Important Questions for Reproduction

 Question 1: Why is DNA copying important in reproduction?

Answer 1. The information related to the inheritance of characteristics from one parent to the next is stored in the DNA. The blueprint for body design is produced as a result of DNA copying. The characteristic features to be transmitted from one generation to the next are maintained by DNA copying. The useful variations essential for species’ survival over time are related to DNA copying.

Question 2: Variation is beneficial to the species, but it is not necessary for the individual. Give the reason.

Answer 2. In species, many individuals of the same type are included. The organisms of a species have a similar body design and are well adapted to their niche and place. When the variation occurs in the individual, it is not beneficial and may even lead to the individual’s death.

Question 3. Explain the difference between binary fission and multiple fission.

Answer 3: 

Binary fission Multiple fission

The parent division leads to the formation of nearly equal-sized daughter individuals. The parent-child division may result in the formation of a large number of small daughter individuals.

Two nuclei are formed. Several nuclei are formed.

For example:

Amoeba and Leishmania divide by binary fission.

For example

Plasmodium and yeast divide by multiple fission.

Question 4: Mention the benefits of reproduction by spores.

Answer 4: The organisms reproducing through spore formation is beneficial in several ways. They are:

Spore formation are a simple and faster mode of reproduction.

They can float in the air as they are light in weight, so the organisms may be dispersed.

Question 5: Mention reasons why more complex organisms do not give rise to new individuals through regeneration.

Answer 5. This is because of the following reasons:

The entire body of simple organisms comprises similar types of cells, so they reproduce through regeneration. The body of complex organisms has a very high degree of organisation.

The particular organs perform a specific function.

Labour division occurs in the body of complex organisms.

Specialised cells are present to carry out regeneration, which is absent in complex organisms.

Question 6: Vegetative propagation is practised for growing some plants. Give a reason and explain why vegetative propagation is important.

Answer 6: The plants that cannot produce seeds or those plants that have non-viable seeds are preferred for vegetative propagation, like, for example, bananas, potatoes, grapes, sugarcane, roses, oranges, etc. The advantages of vegetative propagation are:

The desired features of the parent plant can be easily replicated in the new plants.

The pathogen can eliminate any part of the plant using vegetative propagation.

Question 7: What is the difference between fertilisation and pollination? Explain.

Answer 7:

Pollination Fertilisation

The transfer of pollen grains from the anther to the stigma of a flower is known as pollination. Fertilisation is the fusion of male and female gametes.

Pollination precedes fertilisation. Fertilisation can occur only after pollination, when the pollen grains are germinated and then sent by the male gametes to the ovule.

Pollination carries the male gamete that produces the pollen grainto the female sex organs. Fertilisation brings about the fusion of gametes.

Question 8: Explain the role of the seminal vesicle and prostate gland.

Answer 8. Seminal vesicles are a pair of the thin-walled, muscular, elongated sacs that secrete fluid to nourish and transport the sperms.

To facilitate sperm transport and provide nutrition, the prostate gland secretes fluid into the urethra and seminal vesicles.

Question 9. Define reproduction. Explain the types of reproduction. Mention the characteristic features of asexual reproduction. What are the advantages of sexual over asexual reproduction?

Answer 9: 

The production of new organisms from the existing organisms of a species that ensures the continuity of the population of that species is known as reproduction. It is of two types:

Asexual reproduction

Sexual reproduction.

In asexual reproduction, the offspring is formed from a single parent, and gametes are not fused. The various features of asexual reproduction are:

Only one organism is involved.

Different sexes are not involved.

The cell division occurring is either mitotic or amitotic.

The individuals produced are genetically identical to their parents. The mode of multiplication is rapid.

Gamete formation does not take place.

Fertilisation does not take place.

The process of giving birth to a new offspring or individual through the fusion of male and female gametes is known as sexual reproduction. A diploid zygote is first formed, which develops into a mature organism.

The benefits of sexual reproduction over asexual reproduction are:

The fusion of male and female gametes occurs between two sexually distinct individuals, and the offspring produced has diverse characteristics.

Meiosis during gametogenesis provides opportunities for a new combination of genes.

Origin of new species

Variation for evolution.

Question 10. What is puberty? Mention the changes that occur in girls and boys during puberty.

Answer 10: Puberty is the period of sexual maturity during adolescence when the reproductive organs become functional.

There is the development of secondary sex organs and secondary sex characters in both males and females.

The changes in males are:

The penis and scrotum are enlarged.

Shoulders are broadened.

Muscle development is increased.

The larynx is enlarged.

The voice is deepening due to the thickening of vocal cords.

Growth of pubic hairs.

Development of extra hairs on the face, armpits, and chest.

The puberty changes in women are:

Growth of breast and external genitalia.

Growth of pubic hair and extra hair in the armpits.

Hair on the beard, moustache, and chest is absent.

Pelvis gets broadened.

Initiation of menstruation and ovulation.

Fat deposition in various body parts like the thighs, hips, and shoulders.