8. How do Organisms Reproduce-Text-book Questions Science Class 10 In English

Text-book Questions

Page no. 128 

Q1. What is the importance of DNA copying in reproduction?

Answer: The basic event of reproduction is DNA. to replicate. DNA Cells use various chemical reactions to replicate. In this way DNA in the germ cell Two replicas of DNA during reproduction Replication is very important for an organism's physical structure and design, which enables organisms to live in a specific location.

Q2. Why is variation beneficial to the species but not necessarily for the individual? 

Answer: Variation in organisms is beneficial for the species but it is not necessary for the individual, because the diversity in the organisms provides stability to the population of their species. Any one population is adapted to its niche, but in extreme circumstances, when a niche is no longer favorable to them, then these variations save them from the complete destruction of their population. There are some such organisms in their population which are able to resist those odd changes and they survive, but some individuals die from their population. Therefore, variations are beneficial for maintaining the survival of the population.

Page no. 133 

Q1. How does binary fission differ from multiple fission? 

Answer: binary fission
  1. In this the cells of the organism are divided into two parts.

  2. Cells in bifidation In some organisms such as Amoeba, cell division can take place from any plane whereas in organisms like Lesmania, cell division takes place from a fixed plane.

multiple fission

  1. In this the cells of the organism are divided into many parts.

  2. In multiple fission the organism divides into many daughter cells. For example - Plasmodium.

Q2. How will an organism be benefited if it reproduces through spores?

Answer: Spore is a special type of reproductive structure. Which are very light and due to many reasons these spores get separated from their bunch and spread here and there. These are the reproductive parts of the organism which are protected in adverse conditions due to their thick wall and start growing as soon as they come in contact with the moist surface. Hence, they grow only under favorable conditions.

Q3. Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?

Q4. Why is vegetative propagation practised for growing some types of plants?

Answer: Vegetative propagation is used to grow some plants.

(i) Plants which do not have the ability to produce seeds are propagated only by vegetative propagation.

(ii) Plants grown by this method start producing fruits and flowers in less time than those grown by seed.

(iii) Plants grown by this method have the same fruits and flowers as the parent plants.

Q5. Why is DNA copying an essential part of the process of reproduction?

Answer: Because-

(i) DNA The formation of a replica is the basic event of reproduction which is responsible for the biological development in the progeny organism.

(ii) DN ​​of the nucleus of the cell. a. Contains information for protein synthesis. DNA At the time of replication, the type of information involved in replication, the protein produced is also made of the same type.

(iii) Due to different proteins, there is diversity in the physical design of the organisms. The daughter cells, though similar, differ from each other in some way or the other.

(iv) DNA There is some change in the replication of the original DNA, which are not basically identical, so after reproduction these generations have the ability to tolerate.

Page no. 140

Q1. How is the process of pollination different from fertilisation?

Answer: Pollination process -

(i) The transport of pollen grains from pollination to the stigma is called pollination process.

(ii) Cells are not attached to it.

(iii) Often has to wait for the carriers to complete this action.

fertilization -

(i) The combination of male and female gametes is called fertilization.

(ii) Male and female cells are involved in this.

(ii) This verb is conjunct.

Q2. What is the role of the seminal vesicles and the prostate gland?

Answer: Sperm and prostate gland are present in male and their secretion nourishes the sperms. The prostate gland also secretes a fluid. Through this secretion, sperms are transferred to the female reproductive system, so they are important male glands for reproduction.

Q3. What are the changes seen in girls at the time of puberty?

Answer: Changes seen in girls at the time of puberty -

(i) Hair growth around the genitals.

(ii) Increase in the size of the thorax.

(iii) the onset of menstruation.

Q4: How does the fetus get nourishment in the mother's body?

Answer: The fetus is nourished in the mother's womb. Receives nourishment from mother's blood. It is attached to the mother by a tissue called placenta and through this it receives water, glucose, oxygen and other nutrients.

Q5: If a woman is using Copper-T, will it protect her from sexually transmitted diseases?

Answer: No, Copper-T does not prevent the transfer of sexually transmitted diseases. Copper-T only prevents pregnancy.