CBSE Class 8 Science Reproduction in Animals Assignment Set G

VERY SHORT ANSWER TYPE QUESTIONS:-

I. Tick the correct option:-

1. Internal fertilization occurs

(a)in female body (b)outside female body

(c)in male body (d) outside male body

Ans- (a)in female body

2. A tadpole develops into an adult by the process of

(a)fertilization (b)metamorphosis

(c)embedding (d)budding

Ans- (b)metamorphosis

3. The number of nuclei in the zygote is

(a)none (b)one (c)two (d)four

Ans-(b)one

II. Fill in the blanks:-

1. Puberty is the state of onset of sexual maturity in human beings.

2. Reproduction is very important for continuation of a species.

3. The zygote repeatedly divides to form an embryo.

SHORT ANSWER TYPE QUESTIONS:-

1. Explain the following terms:-

(a) Reproduction- The process of giving rise to new organisms of the same species.

(b) Fertilization-The fusion of male & female gametes.

(c) Zygote- The single-celled structure formed on the fusion of male & female gametes.

(d) Metamorphosis- The gradual transformation of an organism from one form to another during its life cycle

(e) Hermaphrodites-The organisms having both male & female reproductive organs in the same body. Eg:- Earthworm, Leech

(f) Foetus- The mult icellular st ructure formed after the repeated cell divisions in the Zygote formed as a result of fert ilization.

(g) Larva- The act ive form that emerges from the eggs .

(h) Placenta- The specialized t issue that at taches the developing foetus to the uterine wall & provides for it nourishment, respirat ion & excret ion.

2. Give reasons for the following:-

(a) Gender of the result ing offspring is determined by the male parent in humans.

Ans- The Y-chromosome bearing sperm that fert ilizes an ovum results in a male offspring.The X-chromosome bearing sperm that fert ilizes an ovum results in a female offspring.

(b) Sex hormones regulate secondary sexual characters.

Ans- The funct ioning of our reproductive organs is regulated by the sex hormones and oneof the functions is the appearance of secondary sexual characters at puberty.

(c) Platypus & Echidna lay eggs but are not oviparous animals.

Ans- They lay eggs but feed the young ones on milk through the mammary glands.

(d) Sperm needs to have motility.

Ans – Sperms have to enter the female reproductive passage and fertilize the ovum by t ravelling through the vagina & uterus for this in the fallopian tube/ oviduct .

LONG ANSWER TYPE QUESTIONS:-

1. Explain where the embryo stays till it is fully developed and also explain how its nutritional , respiratory & excretory funct ions are carried out .

Ans- The embryo gets at tached to the uterine wall through the Placenta which is a specialized t issue richly supplied by blood & takes care of all the developmental functions of the developing embryo- nut rit ion, respirat ion & excret ion.

2. What is Asexual reproduct ion? What are the advantages of this method?

Ans- The mode of reproduct ion that involves a single organisms & also doesn’t require any special organs or cells. Its advantages are:-

(a) Offsprings produced are identical to the parents so desired traits can be t ransmit ted to the next generat ion

(b) A quick method of reproduct ion

Click on link below to download CBSE Class 8 Science Reproduction in Animals Assignment Set G