Biology Form 5 Chapter 4 60vu

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4551/2 Chapter 4 :Reproduction and growth 2014

4.1 gamete formation No Marking Criteria (a) There are two type of reproduction: sexual and asexual. state four differences between these

Marks

two types of reproduction

Sexual

Asexual

D1-Sexual reproduction involving gametes

Asexual reproduction not involving gametes

1

D2-It involves two individual

It involves only one individual

1

D3-Gamete formed in meiotic division

The process relies on mitotic division

1

D4-The offspring are genetically different The offspring are genetically identical with form parents parent (b)

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4

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Diagram shows the reproductive structures of a flower

Ovary Based on diagram, name the type of reproduction carried out by this plant Sexual reproduction (c)

What is the importance of the type of reproduction mentioned in (a) (i).explain your answer3 F1-there is variation /diversity (in gene composition of the offspring) F2-When conditions become unfavorable some individual may survive F3-and able to reproduce F4-this will prevent the extinction of the species

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The male reproductive system

No (a)

Marking Criteria

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In which organ does cell R is formed Testis

(b)

(g)

(h)

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Explain the importance of both the process of W (mitosis) and X (meiosis) in sperm formation F1-to produce haploid sperm /gamete

1

F2-To ensure continuous species //to ensure the zygote formed through fertilization is diploid

1

F3-Form genetic variation

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What are the main function of male gonad,testes? P1- testes produce male gamete

1

E1-and male hormone

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2

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In which part of testes does spermatogenesis occur? Seminiferous tubules

(i)

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State the function of the tail To propel the sperm forward when swimming toward the ovum

(f)

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What is role Organelle M? To produce energy through cellular respiration for the sperm to swim to the ovum

(e)

1

Name the organelle M which is found abundantly in Part A Mitochondria

(d)

1

Name the process of the formation of cell R Spermatogenesis

(c)

1

Explain the function of scortum? F-to provide optimum temperature

1

E-which is 2-3oC lower than normal body temperature

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Diagram shows a portion of the schematic diagram of formation of sperms

No (a)

(b)

Marking Criteria State the chromosome numbers of cells P, Q and R P: 2n Q: n R: n

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3

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Name the cell division at W and X W: Meiosis I X: Meiosis II

(c)

The female reproductive system

(d)

Name the structure labeled P,Y and R P:Ovary R:Corpus luteum Y :Secondary oocyte


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No (a)

Marking Criteria

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Name the hormone released by pituitary gland stimulates the development of follicles in P Follicle-stimulating hormone(FSH)

(b)

Primary follicle

Graafian follicle

Secondary oocytes

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What would happen if structure R is degenerated immediately after zygote is formed? P1-Level of progesterone will decrease

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P2-Endometrium will break down

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P3-Fertilised egg would not implant in endomentrium and wound be aborted

(i)

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State the process occurs in Y Fertilization

(h)

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In human, explain when the secondary oocyte will change into ovum Secondary oocyte will change into ovum if a sperm penetrate /fertilizes it

(g)

1

What is ovulation ? Ovulation is a process of the releasing of secondary oocyte form ovary

(f)

3

What is process X? Ovulation

(e)

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Name the process that occurs in P that produces secondary oocyte Oogenesis

(d)

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Write the sequence of development of follicle P Ooogenium

(c)

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Formation of primary oocyte takes place during development of a female foetus ,at stage of cell division events does the development stops? Prophase I of meiosis


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No

Marking Criteria

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(a)

Diagram shows the fanges of four types of hormones which control the menstrual cycle follicle development in the ovaries Q

Z

Figure shows follicle development in an ovary. A woman has a problem conceiving due to the failure of process Z.A doctor advises her to take Human chorionic gonadothrophin Hormone (HCG) that has similar function to hormone P Based on the above situation, explain how the HCG injection enables the pregnancy to occur

(b)

F1-The HCG hormone stimulates ovulation //causing the graafian follicle to release secondary oocyte

1

F2-Corpus luteum secretes progesterone to maintain the thickness of the endomantrium

1

F3-Thus enables implantation to occur

1

F1and any F2&F3

1

Explain what happen if the woman fail to produce hormone Q? F1-did not stimulates growth of follicle in the ovary//follicle does not develop into graafian (in the ovary) F2-Primary occyte does not develop into secondary oocyte

(d)

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F3-did not stimulate the production of oestrogen (c)

2

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What are the functions of Q in the process showed in figure above? F-Graafian follicle will release secondary follicle and develop into corpus

1

E-Which will secrete progesterone and oestrogen if pregnancy happen

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2

Explain how the intake of contraceptive pill affects the development of follicles E1-Contraceptive pill contain oestrogen and progesterone hormone

1

E2-High level of oestrogen inhibit secretion of FSH//inhibit development of occyte

1

E3-No ovulation occur

1

E4-Highh level of progesterone inhibit secretion of FSH//inhibit development of occyte Any 3

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Essay enhancement corner No

Marking Criteria

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Diagram shows a physiological process in a human

Based on the diagram above ,describe the physiological process 1 1

P1-the process is oogenesis P2-germinal epithelial cells undergoes mitosis to form diploid oogonia P3-oogonia grow to form diploid primary oocytes

1

P4-the primary oocytes undergoes meiosis I to form haploid secondary oocyte and first polar body P5-secondary oocyte undergo meiosis II and form ovum and (second) polar body

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any 4P


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4.2 The role of hormones in the menstrual cycle No (a)

Marking Criteria

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What is the menstrual cycle? F1: Monthly reproductive cycle controlled by hormones F2: consist of follicle development, ovulation, thickening of endometrium and menstruation

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(b)

(c)

(d)

Based on diagram, state the meaning of menstrual cycle? 2 P1-The production of ovum by the ovary of female P2-follow by a cycle in 28 days Secondary oocyte,copus lutuem,ovulation ,graafian follicle, primary oocyte Using the term given ,write the correct sequence of a complete menstrual cycle Primary occyte ,secondary occyte ,graffian follicle ,ovulation, corpus luteum Pituitary gland is important in the regulation of hormones in the menstrual cycle. Explain its important P1: The pituitary gland produces FSH to stimulate the development of follicles in the ovary. P2 : The follicle secretes oestrogen to repair the uterine Wall P3 : After the 14th day, the pituitary produces LH that causes ovulation.

(e)

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3

Menstrual cycle is a monthly reproductive cycle consisting of follicle development2ovulation ,the changes of the thickness of the endomentrium ,and menstruation .State its importance2 P1-Produce female gamete (Ovum for fertilization) P2-Thickening endomentrium –prepared for implantation of the embryo


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Days

Marking Criteria

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0-7

What is hormone X and Y/P and Q

1

X/P: Follicle stimulating hormone / FSH

1

Y/Q:LH

2

Give a reason for your answer P:On day 13, the hormone is highest/at the peak/maximum level (to stimulate ovulation )

1

Q:Increase in level form day 1 to day 7/8

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2

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State its function of hormone X To stimulate the formation of follicles in the ovary Explain the effect of follicle stimulating hormones (FSH) on structure P(Primary follicle) P1- (FSH) stimulates the growth / development of the primary follicle

1

P2-Structure P will grow / develop / becomes secondary follicle / Grafiaan follicle.

1

2

Name hormone P and Q Hormone P:Oestrogen

1

Hormone Q:Progesterone

1

2

State the function of hormone X(FSH) and Y(LH) Hormone X: stimulate growth and development of several primary follicle (in the ovary to become a Graafian follicle)

1

Hormone Y: Cause ovulation to occur// Promotes development of the corpus luteum to produce progesterone and oestrogen//

1

2

Stimulate completion of meiosis I by changing primary oocytes into a secondary oocyte State the process which took place at X Menstruation

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Based on diagram above ,State one reason to your answer Thickness of the endomentrium is decreasing

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Days

Marking Criteria

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0-7

An imbalance of hormones P (Oestrogen) and Y (LH) causes the disruption of the ovulation process. Explain. Pt. 1 : If P secretion is reduced, Y is inhibited.

1

Pt. 2 : Ovulation is delayed / does not occur

1

Pt. 3 : If P secretion is excessive, secretion of Y is stimulated.

1

Pt. 4 : Inhibits X, no follicle development / ovulation is hastened

1

Pt 5.The size of structure T is smaller than its size on 20th day

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4

Explain why an imbalance of hormones P and Y causes the disruption of the ovulation process. F1: Hormone P is oestrogen and hormone Y is luteinizing hormone

1

F2: undersecretion of hormone P( oestrogen )inhibits secretion of Follicle stimulating hormone from pituitary gland

1

F3: No development of Graafian follicles so no ovulation occur// no secretion of luteinising hormone from pituitary gland so no ovulation occur

1

F4: Oversecretion of hormone P stimulates secretion of hormone Y from pituitary gland F5-Ovulation occur early

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2

Name hormone Q and structure T. Hormone Q : Progesterone

1

Structure T : Corpus luteum

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Days

Marking Criteria

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0-7

Based on the graph in diagram ,Name the hormone 2 P:LH

1

Q:FSH

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2

Give a reason for your answer P:On day 13, the hormone is highest/at the peak/maximum level (to stimulate ovulation )

1

Q:Increase in level form day 1 to day 7/8

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2

1

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8-14

State the function of hormone Y Hormone Y:Cause ovulation to occur// Promotes development of the corpus luteum to produce progesterone and oestrogen// Stimulate completion of meiosis I by changing primary oocytes into a secondary oocyte Explain the effect if the level of hormone Y is low P1- Ovulation will not occur

1

P2-Grafiaan follicle will not release the secondary oocyte (into the Fallopian tube).

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2

Explain one difference between primary oocyte and secondary oocyte Difference: primary oocyte is diploid while secondary oocyte is haploid.

1

Explanation : Primary oocyte has undergo meiosis (I)

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Days 15-21

Marking Criteria

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Explain the importance of structure Q (corpus luteum)during development F- Q secrete progesterone

1

P1-(progesterone will thickened and) maintained the endometrium wall

1

P2-Endometrium wall ready for implantation of embryo // prevent misscarriage / abortion.

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3

2

2

Hormone X

Structure Y

Complete the follicle development in boxes M and N Based on the diagram ,explain the relationship between the P1-After ovulation /corpus luteum secretes S /Progestrone

1

P2-The level of S /progrestrone increase to maintain the thickness of the endomentrium

1

P3-When the M /corpus luteum degenerates, the level of S progesterone decreases, the endomentrium begi to disintegrates

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3

If the fertilization occurred, the level of hormones S is maintained and the pregnancy is proceed Explain the important of hormone S[GnRH] P1-To inhibit the secretion of FSH of LH form pituitary gland

1

P2-no development of follicle /secondary oocyte

1

P3-then the secretion of oestrogen is reduced

1

P4-Repair rejuvenation of endomentrium is not happened

1

P5-Hence no new early embryo develops

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Explain the relationship between structure Y and the level of hormone X form 16 th day to 28th day P1-16th day to 28th day: Y is formed ,hormone X is secreted,endometrium thickens th -

th

P2-23 28 days: Y degenerated, the level of hormone x declines resulting in the foetus


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Days

Marking Criteria

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22-28

Complete the graph starting for point X in diagram to show the change in the thickness of endometrium wall if fertilization does not occur 1

wall is decreasing / thinning.

1

Explain the graph that you draw in above P1- Corpus luteum degenerate

1

P2-No progesterone is secreted (to thicken the endometrium wall).

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2

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Draw in Diagram 6, structure T on the 26th day if fertilization did not take place. The structure T shrinks. Draw in Diagram 4, structure T on the 26" day if fertilization did not occur.1 Corpus luteum had shrunken/ become smaller in size Give the relationship between the structure Q and the level of hormone Q(Progesterone) from the 16th to 28th day2 Pt.1 : On the 16th day, T is formed, hormone Q is secreted.

1

Pt 2 : On the 24th day, T degenerates, the level of hormoneQ declines.

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Days

Marking Criteria

Marks

22-28

Explain the relationship between the structure T and the level of hormone Q from the 16" to 28" day.2 16" to 28" F1: hormone Q( progesterone) rises to a high level to induce endomentrium to thicken and vascuiarised

1

E1-stucture T (corpus luteum) developed and become active

1

F2: hormone Q decreases to a very low level resulting in menstruation

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E2: Structure T degenerated and not active

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Essay Enchancement Corner No

Marking Criteria

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(a)

Based on diagram, state the meaning of menstrual cycle?2 P1-The production of ovum by the ovary of female P2-follow by a cycle in 28 days Starting with hormone produced by pituitary gland and ovary, describe how the hormone regulate the menstrual cycle and an ovary produced an ovum8 F1-What FSH/hormone P does  it stimulates the development of the follicle in the ovariesUsually one follicle ripens to become the graafina follicle in one of the ovaries during each cycle  It also stimulates the follicle in the ovary to secrete oestrogen F2-Effects of oestrogen /hormone X  After menstruation ,it causes the repair and growth of the uterine lining(endomentrium)  The urine lining become thick and spongy with blood vessels  A high concentration of oestrogen in the blood inhibitsFSH production ,preventing the ripening and growth of more follicles  It stimulates the pituitary gland to secrete luteinizing hormone(LH) F3-Function of LH/Hormone R  It causes ovulation  It also causes the formation of the corpus F4-Corpus luteum


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

1

The corpus luteum secretes progesterone and also some oestrogen

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F5-Function of progesterone /Hormone Y  It keeps the uterine lining thick and well supplied wiuth blood  Preparing it for implantation of the embryo  It inhibit both FSH and LH production

No

Marking Criteria

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(b)

Explain the relationship between development of the follicle , changing of the respective hormonal level in the blood and the thickening of the uterine endometrium in a female.10 Day 0 – 7 Follicle – very small – start to develop when receive FSH from pituitary – the wall of follicle will produce estrogen FSH - pituitary start to release FSH, FSH will go to the ovary - FSH stimulate development of follicle Endometrium - stimulate by estrogen; undergo thickening / repairing Day 8 – 14 Follicle - become larger, develop to form follicle Graaf FSH / LH/ Estrogen/progesterone - FSH decrease, LH at maximum level , estrogen at maximum level


10

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- LH stimulate ovulation / completion of meiosis I, estrogen stimulate the thickening of endometrium - Progesterone level very low Endometrium - endometrium become very thick (ready to implantation (of embryo)) Day 15 – 21 Follicle - Follicle undergoes ovulation/ released oocyte II - The remaining follicle tissue / corpus luteum secreted small amount of estrogen but large amount of progesterone FSH/ LH/ Estrogen/ Progesterone - Progesterone stimulated the thickening of endometrium , halted the secretion of FSH/LH - Development of new follicle and ovulation stop. Endometrium - more thicker and highly vascular - ready for implantation of embryo Day 22 – 28 Corpus luteum - if no fertilisation, corpus luteum become disintegrate FSH/ LH/ Estrogen / Progesterone - FSH, LH and estrogen at minimum level; progesterone level also drop Endometrium - endometrium become breakdown & disintegrate - blood and tissue are shed / lining of uterus discharge through vagina as menstrual flow.


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No

Marking Criteria

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(c)

Based on the above diagram, explain how pituitary hormones and sex hormones control the menstrual cycle F1-During day 1 to day 5, endopsperm wall break down and slough off F2-Pituitary land starts secreting FSH E1-FSH causes a Graafian follicle to develop in the ovary E2-during day 5 to day 10 FAH stimulate the wall of follicle and the tissue of the ovary to secrete oestrogen E3-Oestrogen starts to repair of the uterine wall F3-Ion day 12 to day 14 Oestrogen inhibits pituitary gland form secreting FSH E4-and stimulates pituitary glands to produce LH F4-Lh causes ovulation to occur on day 14 E5-After day 14,the graafian follicle to change into corpus luteum F5-Corpus luteum secretes progesterone E5-Progresteron make up the endometruim become thicken and filled with numerous blood vessel for implantation E6-Increase in the concentration of progesterone will inhibit the production of FSH and LH


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No

Marking Criteria

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Digram shows the hormonal secretion and regilaiton the menstraul cycle .Based on the diagram dicuss the relationship between the following i. hormonal level and the development of follicles P1- Pituitary secrete more FSH P2- FSH reansport to the ovary by blood P3- FSH stimulate development of the follicle P4- When the follicle dvelops into graafian follicle ,level if FAH will reduce

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ii.Ovulation and formaiton of the luteum P1- When graafian follicle form ,LH will secreted by pituirary P2- Level of LH become maximum at day 10-14/fertile time form women P3- LH will stimulate the ovulaiton P4- When follicle release the secondary oocyte into fallopian tube ,the folliucle withoutsecondaryoocyte called carpos luteum iii. Homonal levels and changes in thickness of the endomantrium P1- Wall of the follicel secretes oestrogen P2- It wil stimulate the thickening of endomentrium for implatation P3- When ovulaiton ovvurs,the secretion of oestrogen stops P4- Corpus luteum will secretes progestron to continue the funciton of oestrogen P5- When menstrual occur ,oestrogen and progesterone level will decreas


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No

Marking Criteria

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Explain the changes and the functions of each type of hormone produced by Pituitary and ovary. FSH (Follicle – stimulating hormone) 1 1 1

P1 - From day 1 to day 5, pituitary gland stars to secrete FSH P2 - FSH stimulates the development of follicle P3 - And stimulates the tissue of ovary to secrete oestrogen Oestrogen P4 - From day 5 to day 13, concentration of oestrogen continue to increase

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P5 - Oestrogen causes the repair and heal of the endometrium lining P6 - Endometrium lining becomes thicker and ( filled with blood vessels) LH (Luteinising Hormone)

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P7 - On day 13, the LH level increases P8 - Causing ovulation / Graafian follicle releases secondary oocyte. P9 - LH causes the formation of corpus luteum P10 - Corpus luteum secretes progesterone Progesterone P11 - Progesterone maintains the thickening of endometrium for implantation P12 - Progesterone inhibits the secretion of FSH and LH P13 - If the secondary oocyte is not fertilised by a sperm, corpus luteum disintegrate / progesterone decreases P14 - Endometrium lining begins to breakdown and menstruation starts

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Any 8 P


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No

Marking Criteria

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Based on the diagram state the meaning of menstuaration F1-breakdown of the lining of the uterus P1-diacharge through the vagina P2-small amount of blood and some cell

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Describe how the menstrual cycle is affected if the pituitary hormones peak up seven days later. F1 - Menstruation / menses will occur a week later (than usual) // on the 7th day of the following cycle / month. E1 - FSH peaks up on day-20 / a week later / just before day-21. E2 - LH peaks up on day 20 / a week later / just before day-21. F2 - ovulation only occur a week later / day-21 E3 - due to stimulation / from a rise of LH F3 - level of estrogen remains high until day-21 because E4 - graafian follicle that release estrogen remains intact / due tono LH F4 - corpus luteum will only be formed on day-21 / a week later E5 - this causes level of progesterone to increase after day 21 andremains high E6 - as level of progesterone high, the lining of uterine wall / endometrium will remains thick longer E7 - when corpus luteum degenerate, level of progesterone drops E8 - this causes the lining of endometrium to disintegrate causing menses which occurs a week later than usual Any 10


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4.3 Early Development of human zygote Diagram 1 shows the development of a human zygote .

P

P

Q

Q

Label the diagram Stage

Name of the stage / process

X

Ovulation

Y

Fertilisation

P

Zygote

Q

Morula

Z

Implantation


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Early Development of human zygote No

SPM 2012 Marking Criteria

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(a)

Describe the development in detail 8 1 1 1 1 1 1 1 1 1

P1-A fertilization ovum is known as a zygote P2-Zygote divides repeatly by mitois P3-Morula develops into balstula/blastocytst P4-It is a hollow ball of cells P6-Blastocyst forms inner mass cells and trophoblast P7-Blastocyst implants at the endomentrium /uterus P8-Inner mass cells /zygotes develops into embryo P9-trophoblast will form villi of placenta any 8P

8

(b)

Describe the process which occurred form P and Q 4 P1 – Ovulation releases a secondary oocyte , which enters the oviduct. P2 – The secondary oocyte starts meiosis II which progresses until metaphase II. P3 – The nuclei of a sperm cell (n) and the ovum (n) fuse and form a diploid zygote (2n). // A sperm fertilize the ovum to form a zygote. P4 –Zygote begins to divide repeatedly by mitosis as it travels along the fallopian tube towards the uterus. P5 – Morula is form followed by blastula. P6 – Implantation occur / The blastocyst attaches itself to the endometrium.


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No

Marking Criteria

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(c)

Based on the diagram above (i) Explain briefly process A F1-ovulaiton P1-he release of secondary oocyte form the ovary

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(ii) Describe the early development of a zygote form process B until process C P1-after fertilization the zygoite divide repeatly/undergoes mitosis P2-as its travel along the (fallopian) tube toward uterus P3-first division form two-celled embryo P4-further division formed a solid mass of cells called morula P5-then morula is ball of about 100 cells called blastocyts/blastula P6-Blastocyst/blastula is a fluid filled sphere with outer layer of cells and inner cell mass P7-The cilia in the (fallopian ) tube helps developing embryo to reach the uterus P8-Blascocyts/blastula undergoes implantation to attach itself to the endomentrium P9-The inner cell mass becomes firmly embedded in the endomentrium

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8

The formation of twins No (a)

Marking Criteria Diagram shows the formation of two pairs of twins Based on the diagram ,explain how the formation of twin occurs6 F-Siamese twin P1-One sperm and one ovum are involve in fertilization P2-to produce one /single zygote P3-Zygote undergoes mitosis repeatly to form blastocyst P4-Blastocyts does not divide completely P5-the blastocyt does not dvide completely P6-The two blastocyst implant/embedded into endomentrium wall and develop to embryo) P6-The are ed at certainly part of body


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Comparison of the twins Refer to

SPM 2005

Q7

No

Pg 312-314 Marking Criteria

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(b)

Based on diagram ,explain the role of placenta as endocrine gland P1 : After the placenta is formed, it secretes progesterone P2 : The level of progesterone continues to increase P3: The hormone maintains the thickness of the uterus lining


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No

Marking Criteria

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(a)

Diagram 4.1 shows a graph on how the endometrium in the human uterus varies in thickness with time. Fertilization took place on the 16th day of the second month.

State the process which took place at X.1 Menstruation

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(b)

Based on the Diagram 4.1, state one reason to your answer in (i)1 The endometrium begins to break down

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(c)

Complete the graph in Diagram 4.1 to show the changes in the thickness of the endometrium after day 22 in the second month until day 28 of the third month.1

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(d)

Explain why the thickness of the endometrium changes in the way shown in (b) (i).2 P1 : The endometrium begin to became thicker, for preparation for the implantation of a fertilized ovum P2 : The endometrium keep thickening due to the level of progesterone and oestrogen continue to rise because fertilization occurs. P3 : The corpus luteum continues to secrete oestrogen and Progesterone

(e)

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Based on the changes in Diagram 3.1, complete Diagram 3.2 to indicate the level of the hormone progesterone from the first to the third months.2

Explain the changes in the level of progesterone in the three months as shown in Diagram P1 : Increasing in progesterone level will stimulate the uterine wall to became thicker P2 :When the fertilization occur, the level of progesterone continue to rise to ensure the uterine walls continue to grow and nourish the embryo


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No (f)

Marking Criteria

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Explain the changes in the level of progesterone when the women faces menopause. P1 :The level of progesterone become lower

1

P2: Ovaries are less stimulated by FSH and LH

1

P3: lead to inhibits the development of the follicles and ovulation

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3

(g)

Diagram 4.3 shows the process of sperm formation in the human testis.2 Are cells V, cell W and cell X genetically identical? Explain. 1

F : Cell V is similar to cell W but is different from cell X. P : Cell V and cell W are products of mitosis whereas cell X is a product of meiosis.

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2

The function of the placenta in foetal development No

Marking Criteria

Marks

(a)

R

Name two materials that via R(Placenta) form mother to the foetus Water/amino acid/glucose/nutrient/oxygen /antibodies

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1

(b) (i)

Name M Amniotic fluid

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(ii)

State the importance in fluid M P1-Protect the foetus by absorbing shock

1

P2-Protects foetus form physical damage

1

P3-Allow movement of the foetus any one

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No (c)

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Explain how the structure R (Placenta) enable exchange of material to take place 2 1 1

F1-Placenta has a large surface area to volume ratio P1-to increase exchange rate OR F2-Material and embryonic bloods are brought into close

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P2-Diffusion can take place efficiently OR F3-Seperated only by a thin membrane P3-Diffusion can take place efficiently

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(d) P

Structure P consists of two type of blood vessels. Name both vessels 1. Umbilical artery 2. Umbilical vein (e) (i)

State the function of each blood vessel named in above/ Give the diference between both blood vessel 1. Carry waste product/deoxygenated blood form the foetus to the placenta 2. Carry oxygenated blood form placenta to the foetus

(ii)

State two substances which are carried by the blood in Y, in the direction of the arrow 1. Carbon dioxide 2. Nitrogenous waste products

(f)

A pregnant woman of blood group A is having a foetus of blood group B. Based on diagram 5.1 and the statement above , state whether agglutination will occur in the foetal blood or not. Explain your answer. F- No E- The foetal circulatory system and the maternal circulatory system are separated // not directly connected (due to the presence of the placenta)

(g)

Placenta also involved in endocrine system ,discuss how placenta act as endocrine system P1-placenta secretes oestrogen and progesterone P2-helps maintain a thicked ,blood enriched endomentrium during pregnancy


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No (a)

(b)

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Marks

State the differences between the content of R (placenta) and foetal blood R (placenta) Foetal blood Oxygen High Low Nutrient High Low Carbon dioxide Low High Waste /example Low High

1 1 1 1

Diagram 5.2 shows a negative habit of a pregnant mother. . Explain the effect of this habit to the foetus3

P1 : Cigarette contain nicotine / DDT / lead particles. P2 : Nicotine are small in sizes so it can diffuse from maternal blood capillaries to foetal blood capillaries through the placenta P3 : The substances are carried by umbilical vein to the foetus. P4 : The substances can cause miscarriage // birth defect // illness in the resulting baby (c)

1 1 1 1

4

1 1 1

3

th

In the 16 week, pregnant mother was infected with disease .the infection caused structure n to stop functioning the mother miscarriage, explain the statement F1-N secrete progesterone to stimulate/induce the thickening endomentruim E1-Infection caused N not to secrete progesterone E2-Endometrium are no longer thicken //endometrium break down o foetus is aborted

(d)

4

Human chorionic gonadtrophin hormones (HCG) has a similar role to luteinizing hormone(LH).A wife .A wife has a problem conceiving due to the failure in ovulation . The wife becomes after doctors has given her injections of HCG Based on above statement, explain how HCG injection enable the process of pregnancy. P1-HCG stimulates ovulation P2-ovum/secondary oocytes is released form the ovary to the fallopian tube P3-Ovum fuses with sperm in fallopian tube forming a zygote P4-corpus luteum secretes progesterone P5-progesterone maintains the thickeness of the uterine wall /endometrium P6-the thickness of the uterine wall enables implantation to occur


any three

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4

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Essay Enhancement corner No (a)

Marking Criteria

Marks

Diagram shows the structure of placenta Space filled with maternal blood Foetal blood Umbilical artery Umbilical vein Placenta

Explain the function of placenta in foetal development 6 P1-Seperates foetal blood form maternal blood

1

P2-Exchange of substances between foetus and mother

1

P3-Oxygen and nutrient diffuse form the maternal blood to the foetal blood

1

P4-Carbon dioxide and nitrogenous waste products diffuse form the feotal blood into the maternal blood

1

P4-Carbon dioxide and( nitrogenous) waste products diffuses form the foetal blood into the maternal blood

1

P5-Some antibodies diffuse for the maternal blood into the foetal blood

1

P6-Protect the feotus form the high pressure of maternal blood

1

P7-Prevents large organism like bacteria form entering the foetal blood

1

P8-Prevents mixing of foetal blood with maternal blood/agglutination any 6P (b)

The developing foetus is nourish and protected in the mother‟s uterus Explain the above statement10 N1-Nutrients/oxygen/antibodies /hormones/any 2 example N2-Form maternal are transported to the foetus through umbilical vein N3-Carbon dioxide and nitrogenous waste products form the foetus are transported to the maternal (vein)through umbilical arteries N4-The numerous blood capillaries ( in the chorionic villi provide a large surface area fro diffusion of materials P1-The foetal circulatory system and the maternal circulatory system are separated P2-Prevents certain harmful bacteria and their toxins form entering the foetus P3-Prebents the action of meternl hormones/chemical in mother‟s blood that could harm the developing foetus P4-Prevents the mixing of blood groups of mother and the foetus P5-Which cause Aggulutination P5-Prevents the fine blood vessel of the foetus di not burst P7-Due to blood pressure of the maternal circulation 4N +6P


1

6

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The advantage of having separate foetal and maternal circulatory system No (a)

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Marks

Explain why the foetus has a separate blood circulatory system form his mother2 F-Prevent the mixing of blood groups of the mother and the foetus which may be incompatibles

1

E1-If incompatible bloods mix, they clot agglutinate

1

E2-and cause blockage in important organs/death

1

Or F-Protect the foetus form the high blood pressure of the mother

1

E1-Foetus has fine and delicate blood vessel

1

E2-high blood pressure of mother„s blood will cause the feotl blood vessel burst and damage

1

Or

(b)

F-Prevent the action of maternal hormone /chemical /harmful bacteria

1

E1-From crossing the foetal blood

1

E2-which could harm the development of the foetus any two

1

3

1

1

Name two the materials that partially prevented by placenta form entering the blood of foetus Drug/alcohol/caffeine/nicotine /HIV/rubella virus

(c)

R regresses and cause miscarriage Explain the above statement

(d)

F-Placenta acts as an endocrine gland//secreting

1

E-(these hormone) help to maintain a thickened /blood enriched endomentrium throughout the pregnancy

1

2

Explain why colostrums valuable to the baby immediately after birth 2 F-Colostrums contain antibodies

1

P-To help/baby survive form pathogen

1


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Essay enchancement corner No (a)

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Diagram 9 shows relationship between K and L of placental blood circulatory system.

Explain why K and L circulatory system are not directly connected to each other. F1 both system separated E1 blood of both not mixing E2 permits exchange of gases/food E3 waste product E4 between the foetus and the mother F2 prevent the action of maternal hormone/other chemical E5 in mothers blood E6 which could harm the development of the foetus E7 but the protection is incomplete. E8 Harmful chemical/alcohol/nicotine/morphine/bacteria/toxine/viruses E9 can enter the foetus from mothers blood E10 cause permanent damage F3 (protect foetus) from high blood pressure of maternal circulation.

1 1 1 1 1 1 1 1 1 1 1 1 1 1

Any ten


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4.4Appreciating the contribution of science and technology t human reproduction No

Marking Criteria

(a)

A married couple, who has been married for 10 years, fail to have baby. Examination by a doctor revealed that the husband has a low sperm count. Describe one method that would help the couple to have a child F1-Artificial insemination E1-Sperm form a donor can be obtained form a sperm bank E2-Sperm is injected into the uterus of a woman during ovulation any two

(b)

Marks

If the sperm counts of a husband are too low, artificially insemination can be carries out to overcome this infertility problem. Discuss the appropriate technique should be used P1-the sperm are collected for the husband/taken form sperm banks P2-An inserted directly into the fallopian tube of the wife during ovulation phase

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2

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2

Essay enhancement corner Refer to: SPM 2011 State two infertility problem and explain the various method to overcome infertility problem [6m] Pg 316 No

Marking Criteria

Marks

(a)

A married want to have a baby. But he‟s wife has fallopian tubes blocked problem.it make impossible for her to conceive through the natural process.They insist to have their own child. Describe one modern technique that may be able to help this couple to have their own child. Explain the moral issues related to the suggested technique10 1 1 1 1 1 1 1 1 1 1 1

F-The couple can use the intro-vitro fertilization (IVF) method P1-Mother undergoes hormonal treatment to produce more secondary oocyte P2-A fine laparoscope is used to remove the secondary oocyte form her ovary P3-the secondary ooctye are placed in a Petri dish of culture solution P4-then, sperm form the husband are added to secondary oocyte P5-the sperm and ova fused and become zygote//fertilization is occurred to form zygote P6-The zygote undergoes mitosis to become embryo/eight-cell stage P7-The embryo formed is implanted in the wife uterus P8-A baby born is called as a test-tube baby (f+any7P) Able to explain the moral issues related to the suggested technique of reproductive technology M1-Frezzing and destroying living embryo M2-Vitro fertilization morally acceptable


1 1

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10

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No

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Marks

(b)

Preventing pregnancy and difficulty in having children are two main problems in human reproduction. Based on the statement, discuss the moral issues related to applicationof Science and Technology in overcoming human reproduction‟s problems. Preventing pregnancy F1 Contraceptive method P1 stop ovum from being formed P2 stop the fertilize ovum from developing in the uterus. P3 stop sperm from reaching ovum. F2 Could harm the foetus when a women has the ability to bear a child. F3 Only use contraception for health P4 for health P5 financial reason F4 (Prevention of fertilize egg from developing) is an act of killing. F5 The use of spermicides kills life F6 Religious believe there is only accept natural method of contraception.

1 1 1 1 1 1 1 1 1 1 1 1 1

Overcoming infertility F7 Infertility is the failure of the couple to have a baby P6 due to block fallopian tubes. P7 low sperm count F8 Sperm bank P8 not allowed (religion) if used sperm not from husband, F9 In-vitro fertilization IVF P9 it is wrong to destroy extra embryos P10 abuse the technique to select the sex /zygote P11 to produce perfect offspring F10 Surrogate mother P12 Life of surrogate mother is threatened. Many women assume that as long as they are still getting their

1 1 1 1 1 1 1 1 1 1 1 1 1 1

menstruations , they have plenty of healthy eggs left. But this is not quite true.


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No (c)

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Marks

Explain the contribution of science and technology to human reproduction F-name the methods to overcome infertility E- give explanations F-Artificial insemination E1-Impotence in the husband/ erectile dysfunction requirethe sperm to be collected and then injected into the cervixof the wife time of the woman's ovulation.

1

E2-Low sperm count /immobile sperms/ abnormal sperms of the Husband to be overcomed by obtaining healthy sperms form suitable donor in a sperms bank and then inject into the fallopian tubes of the wife during ovulation.

1

F-In vitro fertilisation ( inoperable blocked fallopian tubes)

1 1

El: Permanent blocked oviducts in the wife prevent Secondary occytes from being fertilized by the sperms. E2: Wife treated with follicle – stimulating Hormone (FSH) and luteinising hormone (LH) to increase the oocyte production.

1

E3: Oocytes collected and placed in a Petri dish containing a suitable medium similar to the fallopian tubes.

1

E4: The oocytes are mixed with the husband's sperms.

1 1 1

E5: 2 days old embryos are transferred into the wife's uterus for implantation. F: In vitro fertilization ( Postponement of motherhood ) / having children later in life. El : Eggs / oocytes of women are collected , frozen and stored when less than 34 years old. E2: Oocytes are used: later when the women decide to stad a family. F: Surrogate mother El : Wife unable to have babies herself. And need another younger , healthier woman to bear her child. E2: Woman become pregnant by artificial insemination or by in vitro fertilization.

1 1 1 1 1

Any 9 correct KS: Ability to describe one treatment method correctly


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No (d)

(e)

Marking Criteria Pregnant woman are advised not to smoke and avoid form drugs and alcohol Explain this statement - Cigarette contain nicotine / DDT / lead particles. - The wall of maternal blood capillaries and the wall of foetal blood capillaries are semipermeable. - Nicotine, drugs and alcohol are small in size. - Nicotine, drugs and alcohol can diffuse from maternal blood capillaries to foetal blood capillaries - through the placenta - The substances carried by umbilical vein to the foetus. - Nicotine, drugs or alcohol can affect the development of foetus - (example) cause disable / miscarriage . birth defect/ illness in the resulting baby.

Marks

1 1 1 1 1 1 1 1

6

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5

Mrs. Ali is a married woman, she has a problem to get pregnant

Explian under what type of condition Method A can be used to help Mr. and Mrs. Ali 5 - Method A is known as in-vitro fertilization (IVF) - Method A is use if the fallopian tubes of Mrs. Ali are blocked. - sperm cannot reach the ovum, fertilization fail to occur. - fertilization has to be done outside the body. - developed zygote/embryo then retransfer and implant in the uterus of Mrs. Ali. - the embryo then undergo normal development in the uterus of Mrs. Ali as normal pregnancy.


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No

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(f)

Discuss the role of Madam X in Method B and issue may arise - Method B is used if the uterus of Mrs. Ali fail to carry the implanted embryo because of damaged or abnormal uterus.

1 1 1 1

- Madam X is the woman who is willing / hired to carry the implanted embryo to full term. - Madam X is known as surrogated mother. - Genetically the baby belongs to Mr. and Mrs. Ali. - Who is the real biological mother of the baby, Mrs. Ali or Madam X - There are cases that the surrogated mother refuse to return the baby to the couple after giving birth (g)

1

1

5

A married do not wish to start a family soon after marriage. Explain the following methods of contraception (i)

Natural method

F1-avoid sex during fertile period/after ovulation /around day 14 ( to prevent conception) P1-Detect ovulation by measuring body‟s temperature daily/rise in body temperature (ii)

Mechanical methods

F2-Using intrauterine device(IUD) P2-Prevents implantation of embryo F3-Using diaphragm P3-Prevnts sperm form entering uterus F4-Using condom P4-Prevent sperm form entering uterus (iii)

1 1

1 1 1 1 1

Chemical method

F5-Taking oral contraceptive pills P5-Prevent formation of foliciles in the ovaries F6-Using spermicides P6-Kill sperm Any F corresponding P


1 1 1 1

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6

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No

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(h)

A husband and wife with seven children plan not to have anymore child. Based on your biological knowledge, explain the method that can be recommended to them 6 F1-Diaphragm P1-Inserted into vagina to cover the cervix to stop sperm ofmr entering the uterus F2-IUD P2-Fitted into uterus by doctor and can be left in the uterus (2 years) and prevent implantation F3-Spermicide P3-Chemical cream /gel /foam is applied to vaginal walls before copulation and kill the sperm ejaculated into vagina F4-Contraceptive pills P4-Prevents ovulation (by inhibiting the secretion of FSH and LH) P5-noth the fallopian tubes are cut and tied ( in an operation ) causes the ovum cannot reach the part of fallopian tube ,fertilization is not occurred

(i)

Marks

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5

Technology in human reproduction has given great contribution to family planning .contraceptive pills, intrauterine deceive (IUD) and vasectomy are example of birth control method in family planning Explain the advantages of the following birth control methods family planning (i) Contraceptive pill P1-Contains oestrogen /progesterone P2-(oestrogen/progesterone hormone) can prevent the formation of follicle in the ovary P3-Prevents ovulation //inhibits the secretion of follicle stimulating Hormone/FSH /Luteinizing hormone/LH P4-No fertilization occur//the woman is not pregnant P5-Effeceint /safe method (of birth control) (ii) Intrauterine device (IUC) P6-(intrauterine) device is inserted into the uterus (by doctors) P6-Left in the uterus (for approximately two, three and five years) P8-irritates the endomtrium /prevents the thickening of the uterine wall P9-Prevent the implantation of embryo P10-No development of zygote /no pregnancy P11-effeicent/safe method (of birth control)

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(iii) Vasectomy P12-the vas deferens are tied cut in a surgical operation P13-The sperm re still produced but cannot be transferred out/reach the uterus/fallopian tube P14-No fertilization P15-effeceint/safe method (of birth control) (P5, P11 and P15, mark awarded once only)


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10

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No

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(g)

Reproduction technology has contributed a lot to human health and population growth. Describe how infertility is overcome in humans using the following methods:  Sperm banking [Bank sperma]  Artificial insemination [Permanian beradas]  In vitro fertilization [Persenyawaan in vitro]  Surrogate mother [Ibu tumpang] Sperm bank  Used when the man/spouse/male suffers from low sperm count/production of weak/unhealthy sperms  Sperms are donated and donor‟s identity is recorded/secret  Genetic biodata of donor and the woman recipient should match for successful fertilization Artificial insemination  Practiced by a couple when the man is sterile  Donor‟s sperm are injected into the womans uterus during ovulation  No sexual intercourse is involved  The genetic background and health of donor is screenned before acceptance


1 1

1 1 1 1

In vitro fertilization  Practiced when the woman‟s ovum cannot be fertilized due to blockage of fallopian tube  Ovum is extracted (from the woman) and fertilized outside the body/in Petri dish/test tube  Fertilized ovum/zygote grows in culture medium  Than it is implanted into the woman‟s uterus Surrogate mother  Method practiced when a woman cannot be pregnant in normal way  The zygote is obtained by invitro fertilization  Another woman is implanted with the couple zygote  (Surrogate mother) carries the baby only until it is born

1

1 1 1 1

1 1 1 1

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10

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No

Marking Criteria

(h)

Menstrual cycle is regulated by hormone which is secreted by pituitary gland and ovary. Married woman usually plans their families by taking contraceptive pill. Based on your knowledge in biology, explain how this pills react as with negative to prevent pregnancy. P1–Contraceptive pills contain (a combination of low) oestrogen and (high) progestron hormone P2 – the pills should be taken between any day from the 1st -5th day of the menstrual cycle, for a duration of 21 days P3–Oestrogen promotes/causes repair / growth of the endometrium (in preparation for implantation) P4- Progestrone maintain the thickness of uterus lining P5 –High level of progesterone inhibit the pituitary‟s production P6- no secretion of FSH / follicle-stimulating hormone P7–no follicle develops in the ovary P8 –no Graafian follicle P9 – less / no secretion of LH by the pituitary gland P10 – Ovulation is low / does not occur P11 – no fertilisation occur

(i)

(j)

Marks

Describe briefly the method of in vitro fertilization (IVF) in human. P1 - Woman is injected with FSH hormone P2 - stimulates growth / developments of follicle in the ovary P3 – (A laparoscope is inserted at the navel to) collect immature ova /ovum from the ovaries // the immature ova/ovum are harvested from the ovaries P4 - then, the ova are placed in (glassware with) culture solution to mature P5 – Sperms are collected and placed in the culture solution . Fertilisation occurs. // the ova then, fertilised with the sperm P6 – leave it within 2 days (48 hours) to enable the zygote to develops/ divide themselves into eight cells P7 – the zygote / embrsyos are placed into the woman/mother uterus (by using a catheter) P8 – the embryos/zygotes are allowed to develop in her uterus until birth Based on your knowledge in biology, what are the moral issues related to this method? M1 – Storage techniques used in IVF produces more than one zygote. What will happen to this zygote M2 – If the uterus of the mother is not strong/ healthy, who is going to accept the zygote? What is the relationship between zygote/child with the surrogate mother M3 – If the husband is infertile, who is going to donate the sperm? What is the relationship between zygote/child with the father M4 – Unmarried women can have their own children / can get pregnant M5 – Tendency of choosing the children gender M6 – There were cases where the surrogate mother develop emotional ties and refuse to be separated from their babies REJECT – RELIGIOUS ORDERS


1 1 1 1 1 1 1 1 1 1 1

10

1 1 1 1 1 1 1 1

6

1 1 1 1 1 1

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6

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No

Marking Criteria

Marks

(l)

A couple, Mr Zafrie and Mrs Munirah had married almost ten years but still do not have any child. After undergone an inspection, they found that the husband does not have any problem but the Fallopian tube of Mrs Munirah is blocked. Based on your biological knowledge in reproduction technology, explain how the couple can have children P1 : means fertilization occurs outside of the body

1 1

P2 : the wife injected with hormone to fasten the development of the secondary oocyte / ovum in ovary

1

P3 : secondary oocyte / ovum release out by using ovulation)

1

F : In-vitro technique

laparoscope (from ovary before

P4 : sperms from husband fertilize with the secondary oocyte in a Petri dish (contains culture medium) P5 : (after fertilization) zygote will divide by mitosis P6 : (after 2 days) formed embryo until eight cells stage P7 : embryo transferred to the endometrium of the uterus wall through cervix (using pippet) P8 : embryo implant at the endometrium of uterus wall and develop P9 : baby that is delivered is called test tube baby P10 : This technique is complicate


1 1 1 1 1 1 1

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No (m)

Marking Criteria “In Malaysia, it is estimated that one baby is abandoned every 10 days in the Klang Valley, and 100 babies abandoned every year nationwide.” The Star Online, September 27, 2008 Discuss the advantages and the disadvantages in the application of science and technology in human reproduction in handling the issue. Advantages: F1 - Sterilise method; vasectomy / by cutting the vas deferens intestes E1 - to prevent the sperms from going to prostate glands// ejaculation does not contain sperms F2 - use of (male) condoms E2 - prevent / reduce chances of sperms from going into cervix / uterus F3 - Use female diaphragm that covers the cervix // Use of female condom which is fitted inside vagina E3 - Block entrance of sperms into the uterus // Prevent entrance of sperms into uterus // sexually transmitted disease F4 - Contraceptive pills // Contraceptive implant// Depo-vera injection E4 - prevent development of follicle // inhibit ovulation // difficulties in implantation of zygote F5- Morning after pill E5- Prevent fertilization/ F6- Sterilization by cutting and tying the fallopian tube E6- Prevent the egg travelling along the fallopian tube / sperms reaching the ovum. Any 8 Disadvantages: B1 - Sterilising method cause permanent disabilities to produce sperm / ovum hence the person is not able to produce off springs anymore B2 – Condoms; sometimes sperms can still penetrate therefore chances of getting pregnant is still there B3 - Pills are unreliable because they have to be taken consistently B4 - All these methods will cause teenages / unmarried adults to increase their sexual activities (because they are not afraid to get pregnant thus increasing the moral issues in the societies). Any 2 A married woman has her uterus removed ,making it impossible for her to conceiving the natural process, If she still wants to have a baby with her husband, suggest what she can do. Justify the technique that can ba used by the couple to conceive 6 F-surrogate mother P1-Another woman is utilized as a surrogate mother P2-the sperm and ovum are contribute by the couple P3-Ovum are fertilized in a petri dish /in-vitro P4-Fertilized egg are allowed to develop to become embryo P5-embryo are transferred to the surrogate mother‟s uterus P6-the surrogate mother become pregnant and the foetus develop in her uterus until birth Any 5


Marks

1 1 1 1 1 1 1 1 1 1 1

1 1 1 1 1

6

1 1 1 1 1 1

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5

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No (n)

Marking Criteria Diagram, 8.3(i) and (ii) show the methods related to human reproduction

Based on the diagram ,describe the method M1-IVF/In vitro fertilization P1-a laparoscope is inserted at the navel to collected immature ovum form ovary P2-The ovum is placed in cultured solution to mature P3-sperm are collected and added to the culture P4-Fertilization occurs//sperms and ovum fused and develop into embryo P5-(after 2-4days) the embryo si transferred/inserted into uterus (through cervix) M2-Diaphragm P6-For female contraceptive method P7-inserted into vagina to cover the cervix P8-to stop sperm entering the uterus

Marks

1 1 1 1 1 1 1 1 1

M1+4P=5 M2+2P=3


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8

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4.5 Sexual reproduction in Flowering plants No (a)

Marking Criteria

Marks

What is fertilization ?2 P1-Process where nucleus o f male gamete fuse with nucleus of female gamete P2-Both gametes are haploid P3-Zygote diploid will form

4.5.1 The formation of pollen grains in the anther No (a)

Marking Criteria

Marks

Diagram shows the formation of Y through process X in a typical plant

Name X and Y X:Meiosis Y:Pollen grains (b)

F2-Hapliod F3-Have very rough surface

3

1

1

Explain how the process you named in (b) take place 1 1 1

P1-Pollinating agent (wind/water/animal) P2-transfer the pollen onto the stigma P3-pollen grain will stick onto the surface of the stigma (e)

1 1 1

Name the process when Y is transferred to stigma Pollination

(d)

2

State two characteristic of Y F1-Have 2 nuclei I.e. tube nucleus and generative nucleus

(c)

1 1

Based on the diagram, explain the formation of pollen grain F-Pollen grains are formed in anther, an anther has four pollen sacs E1-Each pollen sac contains hundreds f cells called pollen mother cells (2n) E2-Each pollen mother cell undergoes meiosis to produces four haploid pollen cells/micro pores (n) E4-The nucleus of each microspores then divided by mitosis to form a tube nucleus and generative nucleus


2

1 1 1 1

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4

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Marking Criteria

Marks

(a)

Diagram shows the transferring of pollen grains onto the stigma and fertilization between male and female gamete Describe the process that take place in diagram 8

P1- Pollen grains transfer onto stigma

1

P2- By pollinating agent e.g. animal /water/wind

1

P3- Pollen grain will stick onto the stigma because stigma is sticky//pollen grain have rough surface P4- The sucrose solution on the stigma stimulate pollen grain to germinate P5- Pollen tube will grow until it reaches the pore at the embryo sac /microphyll P6- Nucleus tube lead the elongation of pollen tube

1 1 1 1 1

P7- As nucleus tube moved forward ,generative nucleus followed behind

1

P8- Generative nucleus undergoes mitosis to form 2 male gamete

1

P9- One of the gamete fertilized the egg cell in the embryo sac to form diploid zygote

1

P10- The other male gamete fertilized 2 polar nuclei to form triploid endosperm

1

P11- Both processes take place at the same time ,so it called double fertilization


1

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No (b)

Marking Criteria

Marks

Sexual reproduction in plants involve the production of pollen grains and ovules (a) By using a flow chart describe how pollen grains are formed in plants. Pollen sac

C1

Pollen parental cell C2 Meiosis C3 microspores C4 Pollens

Able to describe how pollen grains are formed in plants 

Pollen grains are male gametes (produced in the anther/pollen sac



(pollen sac) contains diploid pollen parental cell/ pollen mother cell/ microspore

1 1

mother cell 1



(each pollen mother cell) undergoes meiosis



Producing 4 haploid microspores(n)



nucleus of (every) microspore undergoes mitosis forming two nuclei



The generative nucleus and the tube nucleus



Microspore with surfaces adapted for dispersion and is now called pollen


1 1 1 1

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6

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No

Marking Criteria

Marks

(c)

Diagram (i) and (ii) shows the formation of pollen grain and development of the embyo sac .Describe both processes 8 Pollen grains G1-Pollen is produced in the anther (which consists of four pollen sacs) G2-each pollen sac contain hundred of pollen mother cells which is diploid G3-each mother cells undergoes meiosis to form four haploid microspores/cells/tetrad G4-The nucleus of each cell/microspore/tetrad indergoes mitosis to form (pollen )tube and a generative nucleus

1 1 1 1

Embryo sacs E1-Embryo sac mother cell (diploid /2n)undergoes meiosis to form four haploid cells /megaspores E2-three of the/megaspores degenerate, leaving only one (in the ovule) E3-Nuclues of megaspores undergoes mitosis three times to form eight haploid bnuclei E4-Three of eight nuclei migrate to one end of the cell to form antipodal cells E5-Another two nuclei/polar nuclei move to the centre E6-(near the opening of ovule /micropyle) one of three nuclei develops into egg cell/female flanked by two synergid cells E7-The structure is known as embryo sac


1 1 1 1 1 1 1

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No

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(d)

Based on diagram ,Describe the process that occurs in the anther 1 1 1 1 1 1 1

P1 Pollen mother cells in the pollen sac are diploid cells P2 These cells undergoes meiosis P3 to produce four haploid microspores/ tetrad P4 Nucleus of each microspore divides by mitosis P5 Forming haploid tube nucleus and generative nucleus P6 These microspores develop into pollen grains (e)

6

Diagram shows the formation of pollen grain in anther of a plant

Based on the diagram, explain the formation of pollen grain F-Pollen grains are formed in anther, an anther has four pollen sacs E1-Each pollen sac contains hundreds f cells called pollen mother cells (2n) E2-Each pollen mother cell undergoes meiosis to produces four haploid pollen cells/micro pores (n) E4-The nucleus of each microspores then divided by mitosis to form a tube nucleus and generative nucleus


1 1 1 1

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4

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4.5.2The formaiton of the embyyo sac in the ovule No

Marking Criteria

Marks

(a)

1 1

Name the structure Y Mega spore/Embryo (b)

2

In diagram, complete and label the mature embryo sac Based in diagram, Explain the formation of a mature embryo sac 1 1 1

P1-Embryo sac mother cell divides by meiosis to form haploid cells P2-(three haploid cell degenerate,while one haploid cell develop into a haploid megaspore P3-The nucleus in the mega spores divides 3 times mitotically ) to produce 8 haploid cells P4-One cell form the egg cell,2 cell form the polar nuclei.3 cells form the anti podal cells and 2 cells form the synergid cells

1

4

Fertilization in plant occurs when receive nucleus in pollen grain fused with the nucleus in embryo sac in ovule .Based on your biology knowledge ,explain the development of ovule to form mature embryo sac F-The ovule develops form the ovarian tissue

1 1 1 1

E1-Inside the ovule is a central mass of parenchyma tissue/nucellus E2-only one diploid cell megaspores /embryo sac mother cell(2n) enlarges E3-Embryo sac mother cell undergoes meiosis to form a row of four haploid/megaspores E4-three of the four megaspore enlarges and nucleus undergoes mitosis three times to form eight haploid nuclei

1

E5-The left megaspore enlarges and nucleus undergoes mitosis three times to form eight haploid nuclei

1

E6-Three of the eight (migrate to one end of the cell) to form antipodal cells, another two nuclei to form polar nuclei develops into an egg cell/female gamete/ovum and to synergids cell any 6

1 1


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4.5.3Formation of the pollen tube, zygote and triploid No (a)

Marking Criteria

Marks

Diagram shows the germination of pollen tube towards the embryo sac in flowering plants

Based on diagram 5.2, explain the fertilization process in embryo sac P1-One male gamete will fuse the egg cell to form a diploid zygote P2-Another male gamete will fuse with 2 polar nuclei to form triploid nucleus P3-Both process take place at the same time //double fertilization occurs (b)

1 1 1

3

1

1

1 1 1 1

3

Reproduction in plants involves the fusion of male gamete and female gamete.diagram 4.2 shows a male gamete 4.3 shows the early stage of double fertilization in flowering T

Based on the diagram name the structure S Polen grain (c)

Explain what happen to structure S when it land on structure T F1-Sucrose solution /sugar on structure T stimulate germination of S F2-Pollen tube grows out the ovary F3-It grows down (the style) into ovary F4-enter ovule through microphyle


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No (e)

Marking Criteria

Marks

Complete diagram 4.4 below to shows how double fertilization occurs

The diagram 4 shows the process of double fertilization in a flowering plants Criteria of the diagram : Correct drawing with pollen tube enter through the microphyle end

-1

Correct drawing of embryo sac with 2 polar nuclei and egg nucleus inside- 1 Correct drawing of pollen tube with 2 male nuclei with correct labels

-1

1 1 1

3

(f)

Name the cells contains in Y that involves in double fertilization process 2 polar nuclei//1 egg cell (g)

1

How structure W cause the formation of structure X F-W rough sticky wall E1-(sticky wall)stimulate the germination /elongation of structure X to embryo sac

(h)

1

1 1

2

1

1

State the two nuclei found in the structure X Nucleus tube and generative nucleus /male gamete


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No (i)

Marking Criteria

Marks

Describe briefly the movement of structure X P1-X secretes enzymes to digest the surrounding tissue as it grows downward P2-the direction of growth of structure X is controlled by the nucleus tube which at the tip of the structure

(j)

1 1

2

Explain why the fertilization process is process is known double fertilization 1

P1-because there are two fertilization P2-First fertilization happen when one of the male gamete fuses with the egg to form zygote P3-The second fertilization happens when the other male gamete fuses with the two polar nuclei to form a triploid nucleus (3n)/endosperm (k)

1 1

3

1 1 1 1

3

Explain what happen happens to the structure Y after double fertilization? P1-Nuclues triploid /zygote triploid undergoes mitosis P2-Then develop to endosperm P3-Zygote develop to embryo P4-(endosperm) store the food for the development of embryo/seed germination


Marking Criteria

(a)

The product form the process in (a) is transferred onto the stigma through pollination Explain the process that will occur in the style and ovary after pollination P1 On the stigma, sugar stimulates pollen grains to germinate P2 Form pollen tube P3 Pollen tubes grows into the style and towards the ovule, led by tube nucleus P4 Generative nucleus undergoes mitosis and form two male gamete nuclei P5 Pollen tube penetrates the ovule through micropyle

Marks

1 1 1 1 1 1

P6 Tube nucleus disintegrates P7 One male nuclei fuses with the egg cells to form diploid zygote P8 Another male nucleus fuses with the two polar nuclei to form triploid zygote P9 This process is known as double fertilization P10 Triploid nucleus divide to form endosperm (ie nutritive tissues) P11 Diploid zygote divides and grows into embryo


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No (b)

Marking Criteria

Marks

Diagram shows the proves of fertilization in flowering plants Pollen grains

Ovary

Mature embryo sac

Based on diagram describe how this process occurs

10

P1-Pollen grains have been released form the anther to the stigma for pollination by insect to wind P2-When pollen grain lands on stigma, epidermal cell secrete sucrose solution P3-(sucrose solution) stimulates the pollen grain to germinate and pollen tube P4-the pollen tube grows down the style to ward th ovule P5-it secretes enzyme to digest surrounding tissues as it grow downward P6-The generative nucleus (follows behind it) divides by mitosis to form two male gamete nuclei P7-the male gamete nuclei move down the pollen tube lead by the tube nucleus P8-when the pollen tube reaches the ovary, it penetrates the ovule through the microphyle P9-The tube nucleus degenerates, leaving a clear age for the male nuclei to enter the embryo sac

1 1 1 1 1 1 1 1 1

P10-one male gamete fuses with two polar nuclei to form triploid nucleus which divide by mitosis to form endosperm tissue

1

P12-this fertilization is called double fertilization

1


any 10 point

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No

Marking Criteria

Marks

(c)

Based on the diagram ,explain how double fertilization occurs in the plant10 1

P1-Anther produces pollen grains .male gamete P2-Polen mother cell (in the anther) undergoes meiosis to produce (four) megaspores (n)/haploid cells /tetrad

1 1 1

P3-Megaspores (n)/haploid cells /tetrad develop into pollen grains P4-The nucleus of each megaspores (n)/haploid cell /divides by mitosis P5-to form one tube nucleus and one generative nucleus

1 1

P6-When a pollen grain falls on the stigma P7-Stimulates (the pollen grain to germinate to) form pollen tube

1 1

P8-(during the growth of pollen tube) the generative nucleus divides mitotically P9-to produce two male gametes P10- to the male gametes move/follow behind the tube nucleus (down the pollen tube until they

1

reach the microphyle 1

P11-The tube nucleus disintegrates and the two male gametes enter the embryo sac P12-(during double fertilization ), one male gamete fuses with the egg cell/ovum to form a

1

diploid zygote and P13-The other male gamete fuses with two polar nuclei to form a triploid nucleus (so double fertilization occurs)

1

any 10


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No (d)

Marking Criteria

Marks

Diagram shows the process of double fertilization in the flowering plant

Describe the process P1-One of the male nuclei which is x fuses with egg cell nucleus which is D

1 1 1 1 1 1

P2-the other form a diploid Zygote P3-The other male nucleus fuses with two polar nuclei which is C P4-To form nucleus divides to form the endosperm P5-This triploid nucleus divides to form the endosperm P5-That will provide food to the embryo (e)

Diagram 7.2 shows the growing of pollen tube in the style and the process of double fertilization in flowering plant. Pollen grains

Sytle Pollen tube Embyro sac

Antipodal cell Polar nucleus Egg cell

Integumens

Pollen tube

Describe the growing process of pollen tube in the style and the process of double fertilization in flowering plant7 Growing of pollen tube process P1- Sugary/sucrose solution stimulate the growing of pollen tube P2 - pollen tube grows down the style towards the ovule P3 - The generative nucleus divides to form two male gametes nuclei P4 - Leading the front is the nucleus tube


1 1 1 1

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Double fertilization P6 - Pollen tube penetrate the micropyle to reach the egg cell P7 - Nucleus tube disintegrate P8 - one of male nucleus fuses with egg cell to form a diploid zygote P9 - other male gamete nucleus fuses with the two polar nuclei forming a triploid nucleus. P10 - which later develops into the endosperm P11 - the synergid cells and the antipodal cells disintegrate Any 7 P

1 1 1 1 1 1

10

4.5.4 The development of seed and fruits after fertilization No (a)

Marking Criteria

Marks

Based on your answer in above, describe the formation of fruit and seed P1-The diploid zygote divides via to form the embryo P2-The embryo develops and differentiates into three part, a radical (young root),plumule (young shoot) and one two cotyledons (seed leaves) P3-(at the same time) the triploid endosperm cell undergoes repeated mitosis to beome endosperm (a food store that nourish embryo after germination )

1 1 1

P4-The intergument forms the testa (seed coat) 1 1 1

P5-The ovule develops into a seed/multiple protect the seed I the ovary P6-the ovary becomes a fruit (which protect the seed and help in its dispersal)

6

4.5.5The importance of fertilization No (a)

(b)

Marking Criteria

Marks

Explain the significant of double fertilization in flowering plant Structure Question P1-Diploid zygote will developed to form an embryo P2-Triploid nucleus will develop to form endosperm tissue P3-Endosperm tissue nourishes the developing embryo any 2

1 1 1

Explain the significant of the process(double fertilization ) that occur in ovaries of flowering plants4 P1 After double fertilisation, the outer layer of ovule dries up and develops a hard seed coat P2 To protect both embryo and endosperm P3 Ovule will develop into seed P4 Ovary enlarges and form fruit P5 Ovary wall develops into fruit wall that cover & protect the fruit P6 This will ensure the flowering plant to survive P8 The endosperm of the seed provides nutrition and energy to the embryo for its growth

1 1 1 1 1 1 1


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3

4

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4.6 Growth in multicellular organism Refer to: SPM 2007 Q7 Based on the diagram explain meaning of growth [4 marks] Pg 318 No

Marking Criteria

Marks

(a)

(b)

Based on the diagram name the diagram labeled T1: Zone of cell division T2: Zone of expansion /elongation T3: Zone of differentiation

1 1 1

3

Name the zone where the primary xylem tissue starts to form? T3//zone of elongation

1

1

1

1

(c)

Give two example of cells that undergoes the process in zone t3 Epidermal cell//phloem cell/xylem cell/root hair cell Essay enhancement corner No (a)

Marking Criteria

Marks

Diagram shows a longitudinal section of shoot tips of a plant

Describe the process of growth in each zone Zone I F1-Cell division stage E1-The number of cells in an organism increase by repeated mitosis


1 1

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No

(b)

Marking Criteria

Marks

Zone II F2-Cell enlargement stage E2-Increase in size and volume of cell through intake of water

1 1

Zone III F3-Cell differentiation stage E3-Unspecialized cell become specialized permanent cells with specific function

1 1

6

Diagram shows the stges of growth X ,Y and Z at tip of plant shoot Zone P,Q,R and S shows the changes that occur in the cells during the stages of the growth

Based on diagram ,Explain the meaning of growth Criteria : P1-Mitosis P2-Increase in the number of cells P3-Elogation of cells P4-Specialisation of cells P5-increase of shoot length P6-The process is irreversible F1-zone P and zone R is cell division /mitosis zone P1-Produces new /number of cells increases F2-zone R is elongation region P2-New vacuole are formed /enlargement of vacuole /increase in the size of cells F3-zone S is differentiation /specialization in zone P3-Differentiation cell are specialized to form specific /permanent of tissue /form specific function /example of tissue F4-Length of shoot increases/Height of the plant increases P4-the process is irreversible

1 1 1 1 1 1 1 1 1 4

Any four


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4.7 The growth curve 4.7.1The parameter for measuring growth No (a)

Marking Criteria

Marks

Diagram 8 shows the growth curve of a maize plant, using dry mass as parameter of growth

Explain how the dry mass of maize plants can be measured over a period of time to be used as a parameter of growth. P1- 50 maize seeds are planted in a nursery bed. P2- The seeds are given the same condition – the same amount of light, water and minerals P3- On day 1, three maize seeds are removed from the nursery bed and heated at 102oC until their combined mass becomes constant. The average dry mass of each maize seed is determined. P4- On day 3, three maize seeds (or seedling, if they have germinated) are taken out and their average dry mass is determine in the above step (On day 1). P5- Three seedling are again removed at every interval of two day (on day %, 7, 9 and so on) and their average dry mass is determined. P6- Changes in the average dry mass of a maize plant are recorded in the form of a table. (b)

Explain the shape of the graph shown in Diagram P1- The growth curve of the maize plant has a sigmoid shape P2- For the period of time from A to B, the dry mass of the plant decreases. P3- This is because the stored food in the seed is oxidized to produce energy for germination. P4- From B to C, leaves have emerged and the young plant begins to make food by photosynthesis. The food is used to make plant tissues. P5- This cause the growth rate to increase. P6- When the maize plant is near maturation, P7- growth slows down and the curve is less steep(CD) P8- During the period from D to E, the plant has reached maturity. The rate of photosynthesis Is equal to the rate of respiration. P9- Hence, there is no more increase in the dry mass of the plant. Growth rate equals zero. P10- When the plant are old, there will be a decrease in the dry mass of the plant (EF). P11- This is because flowers, fruits and the older leaves fall off. The growth rate is negative.


1 1 1

1 1 1

6

1 1 1 1 1 1 1 1 1 1 1

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10

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No

Marking Criteria

Marks

(c)

Explain why the dry mass is the most accurate parameter of growth. P1- The dry mass of an organism is its mass after all its water content has been removed. P2- It is the mass of real tissues in the organism P3- Unlike fresh mass, dry mass is not affected by changes in the water content in the organism.

1 1 1

3

4.7.1 The sigmoid growth curve of an organism No (a)

Marking Criteria On diagram 5.1 label and state all phases that should be in the growth curve2

ABCDE(b)

Marks

Lag phase rapid growth phase slow growth phase Stationary phase Senescence and death phase

Using any phase above ,explain briefly what happen during each phases P1-Lag phase : growth rate is slow P2-Rapid growth phase: growth rate is the fastest P3-Slow growth phase: growth rate is zero P5- Senescence and death phase: old age stage


1 1 1 1 1

2

1 1 1 1

1

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Refer to: SPM 2011

Explain the change occur in each phase

No (a)

[10 marks ]

Pg 315

Marking Criteria

Marks

Graph shows fresh mass of Zea mays plotted against time

2

4

6

8

10 14

15

Based on the graph, which shows the fastest growth rate? Week 4-8 (b)

(c)

1

1

Explain the growth rates as shown by the graph form start to week 8 P1-Negative growth/growth rate is negative form beginning to week 1because germinating seeds use the food stored in the endosperm

1

P2-From week 2-week 4-the growth rate is slow because the leaves are starting to grow(and photosynthesis has just begun)

1

P3-Week 4 –week 8 shows growth rate because plant is actively making food (though photosynthesis)

1

3

1

1

Name the phase f the plant growth after week 8 Mature phase/maturity


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4.7.3 The growth curve of insect Refer to: SPM 2011

Explain the growth of grasshopper [4marks] pg 315

No (a)

Marking Criteria

Marks

On graph 5.2 draw an arrow and label it as Q to shows where the ecdysis begins

Based on diagram 5.2, explain the process that occur during X P1-a new exoskeleton forms below the old exoskeleton P2-the exoskeleton soften and its essential resources are digested and reabsorbed into new skeleton P3-The old exoskeleton then splits and is discarded P4-(before the new exoskeleton hardens), the insect enlarges its body volume by swallowing air or liquid until new cuticle hardenAny 3

1 1 1 1 3

(b)

Graph 5.1 Graph 5.2 A student carried out an experiment to study the growth and life cycle of a rat and grasshopper. The curves for both organism are shown in the diagram 5.1 and 5.2 Give two differences of the growth curve between both organism Growth curve for a rat

Growth curve for a grasshopper

P1

Shaped sigmoid/S

Shaped: staircase

P2-

Has five different phases

Has five instars an imago phase


2 2

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The difference between growth curve of human and insect No (a)

Marking Criteria

Marks

Graph 7(a) and 7(b) show the growth curve of human and insect. Based on the graph , compare the growth process in human and insect.

Similarities S1- height of man / length of instar increases by time

1 1

S2- both show horizontal line / constant growth during adult Difference D1- Form of graph – Sigmoid form for human and like series of steps in insect D2- Age of organism – the height measured yearly, but in insect used day for measuring the length D3- Caused of different – human have endoskeleton but insect have exoskeleton D4- Stages involve – in human, the curve has three different phases, but there are five steps in insect // nymphal stages

1 1 1 1

D5 - Vertical and horizontal line : curve for human did not shows different line (only the curve from continuous points), but there are five different horizontal and vertical lines each

1

D6- Zero growth – no point to show zero growth in human, but there are 5time of zero growth (at horizontal line)

1

D7- Sudden growth : no sudden growth for human, but there are sudden growth in insect (at vertical line)

1

D8- Ecdysis : no ecdysis in human but ecdysis occurred in insect

1 1

D9- Mitosis : the cells in human undergo mitosis all the time, but in insect, mitosis only occurred at certain time (during ecdysis) D10-Absorption of air : in human, there are no absorption of air, but in insect, during ecdysis Max – 10 marks * 2 marks for similarities 8 marks for Differences


1

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No (b)

Marking Criteria Diagram 8.3(i) and 8.3 (ii) ,explain the differences between the growth curve of both organism 4

Explain the differences between insect growth curve and maize growth curve E1-the pattern of growth in maize is sigmoid curve but the pattern of growth in insect is the form of steps E2-growthis an irreversible process which increase the number of cells, size complexity and organ function in the organism body E=2m

Marks

1 1

2

Essay enhancement corner No (a)

Marking Criteria Growth and development does not cease once birth has occurred, instead it continues throughout the stages of life from Infancy to adulthood. Do you agree with the above statement '? Justify your answer. Give opinion F:Relate occurrence of growth and development at each stage of life E: Justification Opinion : Agree F: Infancy ( birth - 2 years ) E 1: Growth and development occur at a rapid .rate. E2: Head and brain develop faster than rest of the body. E3: Lymph tissues well developed ( thymus) to give immunity to diseases F: Childhood E 1 : Period of steady growth and body proportions change. E2: Steady increase in height and organ size. F: Adolescence El : Period of rapid growth/ acceleration of growth. E2: Development of reproductive system, sexual organs become functional I attains puberty/gametogenesis E3: Rapid changes in height, weight, fat distribution and body proportions. E4: Males experience growth spurts later females and grow for a longer period of time. F: Adulthood E 1: Period of no new growth / stationary phase. E2: functional organ system physical peak. E3: Growth and specialization of new cells continue to occur to replace dead cells1 damaged tissues , e.g. blood cells, liver cells , skin cells Any 8 correct KN: Ability to describe the human growth curve correctly /reflects the sigmoid shape.


Marks

1 1 1 1 1 1 1 1 1 1 1 1 1 1

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10

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4.8 The primary and secondary growth in plants Refer to: SPM 2007 (i) State three differences between primary growth an d secondary growth [3 marks] (ii) Explain the benefits to the plant that undergoes secondary growth as compared to those that do not undergo secondary growth [7marks] Pg 318 4.8.1secondary growth No (a)

Marking Criteria

Marks

Diagram 7.3 shows the stages of secondary growth in a dicotyledonous stem.

Explain the process of secondary growth in dicotyledonous stem5 Secondary growth of dicotyledonous stem P1 - Secondary growth of dicotyledonous stem involves vascular cambium and cork cambium P2 - Vascular cambium divides actively by mitosis. P3 - To form ring of cambium / new cells P4 – Cells at inner layer will form secondary xylem P5 – Cells from outer layer will form secondary phloem P6 – Cork cambium divides by mitosis to form new cells P7 – The new cells at the inner layer form parenchyma P8 – The new cells at the outer layer form cork (tissue)

1 1 1 1 1 1 1 1 1

Any 5 P


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5

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No

Marking Criteria

Marks

(b)

Diagram show the stage of secondary growth in the stem of dicotyledons plants. Explain the stage of growth (1 to 4) P1-(secondary growth start)st vascular cambium at the vascular bundle /separated primary xylem and primary phloem//involve the lateral meristem

1

P2-The cambium cell divide radially and merge with vascular cambium to form intervascular cambium

1

P3-(the cambium cell divide) tangentially to produced two layer of cell (one inner layer will form secondary xylem while the other layer will form secondary phloem

1

P5-the primary xylem will pushes towards the pith while the primary phloem will pushes toward to epidermis

1

P6-the walls of secondary xylem become thickened with lignin to give the tissue mechanical strength 9which have to the plant)

1

P7-Cambium cell between the vascular bundle divided to form secondary parenchyma tissue

1 6

P8-(increasing the secondary tissue will ) increase the diameter of the stem (c)

Describe the importance od secondary growth 1 1 1 1

E1-secondary growth increase the perimeter/diameter of the stem E2-to increase the mechanical (and stability) E3-Secondary growth produced more secondary phloem and secondary xylem E4-to water and mineral salt transportation E5-to transport the product of photosynthesis E6-(more secondary xylem tissue produced) to increase when the plants become increase the stem and diameter E7-to increase the lift of the plant of the plant/life longer any 4


1 1 1

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6

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