Solved 2012 Question Paper ICSE Class 10 Biology — Question 12

(i) Draw a well labelled diagram to show the metaphase stage of Mitosis in an animal cell having four chromosomes.

(ii) Mention any two reasons for the population explosion in India.

(iii) Give biological reasons for the following:

1. Pituitary gland is also known as the master gland.
2. Gametes have a haploid number of chromosome. [5]

Answer

(i) Well labelled diagram showing the metaphase stage of Mitosis in an animal cell having four chromosomes is shown below:

(ii) Two reasons for the population explosion in India are:

1. Desire for a male child.
2. Lack of awareness about birth control measures.

(iii) Biological Reasons:

1. Pituitary gland is popularly called as the master gland because it controls the functioning of all the other endocrine glands.
2. Gametes are produced as a result of Meiosis during which the chromosome number is reduced to half and each daughter cell receives half the set of chromosomes.
   These gametes (egg and sperm) unite to form a zygote. If both of them were diploid, the zygote would have twice the number of normal chromosomes and the organism produced would be abnormal.