How Do Organisms Reproduce ? : Complete Set of Questions

This set of questions contains all the possible concepts
which could be asked in the examination

Do Organisms Create Exact Copies of Themselves ?

Q.1 What is reproduction? What are its two types? Which one of the two confers new characteristics on the offspring’s and how?

Reproduction is the process of formation of new young individuals of the similar type of mature living being.

Reproduction is of two types:

(i) Asexual reproduction

(ii) Sexual reproduction

Only sexual reproduction confers new characteristics on the offspring because the process of DNA replication occurs in sexual reproduction. Mutations occur during DNA replication which give rise to variation, thus confers new characteristics on the offspring.

Q.2 How can you say that DNA copying an essential part of the process of reproduction?

The process of reproduction results in the production of offspring’s which are exactly similar to the parents. DNA copying is accompanied by cell division that gives rise to two cells. The exact blue print of body design is inherited in the offspring’s due to DNA replication in parent cell. Therefore, DNA copying is an essential part of the process of reproduction

Q.3 Reproduction is linked to the stability of the species. Justify your statement.

In reproduction, DNA passes from one generation to the next. Copying of DNA takes place with consistency but with minor variations. The consistency of DNA copying during reproduction is important for the maintenance of body design features that allow the organism to use that particular niche. This consistency leads to the stability of the species.Reproduction is therefore linked to the stability of populations of species.

Q.4 Mention any three advantages of variation in individuals.

(i) Variation helps in survival of species.

(ii) It is the basis of evolution.

(iii) It brings adaptation in individuals.

Q.5 What is the effect of DNA copying which is not perfectly accurate in the reproduction process?

During the process of DNA copying, some mutations are produced which give rise to useful, harmful or neutral variations in the offspring.

Q.6 Mention the information source for making proteins in the cell. What is the basic event in reproduction?

The DNA in the nucleus of a cell is the information source for making proteins. If the information is changed different proteins will be made. Different proteins will eventually lead to altered body designs. The basic event in reproduction is the creation of a DNA copy. Cells use chemical reactions to build copies of their DNA. This creates two copies of the DNA in a reproducing cell, and they will need to be separated from each other. DNA copying is accompanied by the creation of an additional cellular apparatus, and then the DNA copies separate, each with its own cellular apparatus.

Q.7 The process of combining DNA from two different individuals during reproduction may result in increased DNA content in each generation. How is this problem taken care of?

The special cells produced in individuals for reproduction have only half the number of chromosomes and half the amount of DNA as compared to the non-reproductive body cells. So, when these special cells, i.e., gametes combine, it results in re-establishment of the chromosome number and DNA content in the new generation.

Q.8 In tobacco plant, the male gametes have twenty–four chromosomes.

(i) What is the number of chromosomes in the female gamete?

(ii) What is the number of chromosomes in the zygote?

(i) 24 chromosomes

(ii) 48 chromosome

Q.9 Why do living organisms reproduce?

Reproduction provides-

(i) Stability to the population of species

(ii) Variations responsible for survival of a species over a period of time (evolution)

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