Biology Paper 3,Nov/Dec 2013  
Questions:   1 2 3 4   Main
General Comments

Question 1

The diagram below is an illustration of the reproductive system of a mammal. Study the diagram and use it to answer questions (a) and (b)

(a) (i) Identify the structure illustrated in the diagram. [1 mark]
(ii) Name the parts labelled I-X. [5 marks]
(iii) State one function each of the parts labelled I, IV, V, VI and X. [5 marks]
(b) (i) Explain briefly how the part labelled VIII is adapted to life. [6 marks]
(ii) Describe briefly the process in humans that gives rise to the formation of the part labelled VIII. [8 marks]


Few candidates were able to identify the structure illustrated correctly. Many candidates could not name the labelled parts correctly and some made spelling mistakes. Few candidates were able to state the function of the parts labelled I, IV, V, VI and X correctly. Many candidates could not explain how the part labelled VIII is adapted to life but a fairly good attempt was made to describe the process in humans that give rise to the formation of the part labelled VIII.

The expected answers are:

1(a) (i) Identification of structure A mammalian/human embryo/foetus in the womb
(ii) Label of parts

I. Placenta
II. Chorion
III. Amnion
IV. Amniotic fluid
V. Vagina/birth canal
VI. Cervix
VII. Uterus/womb/uterine wall
VIII. Embryo/foetus
IX. Umbilical cord
X. Fallopian tube/Oviduct

(iii) Functions of parts labelled I, IV, V, VI and X

I - Exchange of materials between mother and embryo;
IV - Protects the embryo from shock/damage
V - Opening for passage of sperms into the female/delivery of the foetus.
VI - A gateway to the uterus/womb/for passage of sperm/blood/secretes mucus to keep the vagina lubricated/allows passage of foetus.
X - Site for fertilization/receives matured egg/ovum/passage of egg into the uterus.

(b) (i) Adaptation of part labelled VIII/embryo to life The embryo is adapted to life by the placenta; a structure that allows the embryo to remove waste products; through the mother at the same time obtain oxygen; water and digested food/antibodies; presence of amniotic fluid; serves as shock absorber/protects it against injury/damage; highly vascularized umbilical cord; that connects mother to foetus to promote exchange of materials. Note: Structure and function must tally to score.

(ii) Process that leads to formation of part labelled VIII/Embryo/Foetus The process by which the embryo is formed is sexual reproduction; during mating; the male human introduces the erect penis into vagina of a female human; thereby ejaculates/releases sperms into the vagina; sperms swim to the uterus through the cervix; then into the oviduct/fallopian tube to meet a matured egg; which has been released from the ovary/ovulation occurs; sperm(s) fertilize(s) the egg/ovum to form a zygote; which migrates to the womb/uterus; becomes and gets implanted onto the inner lining of the uterus; This develops into the structure labelled VIII/embryo/foetus.

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