Biology
(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:
- Pituitary gland is also known as the master gland.
- Gametes have a haploid number of chromosome.
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:
- Desire for a male child.
- Lack of awareness about birth control measures.
(iii) Biological Reasons:
- Pituitary gland is popularly called as the master gland because it controls the functioning of all the other endocrine glands.
- 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.
Related Questions
A homozygous plant having round (R) and yellow (Y) seed is crossed with homozygous plant having wrinkled (r) and green (y) seeds :
(i) Give the scientific name of the plant on which Mendel conducted his hybridization experiments.
(ii) Give the genotype of the F1 generation.
(iii) Give the dihybrid phenotypic ratio and the phenotype of the offspring of the F2 generation when two plants of the F1 generation are crossed.
(iv) Name and state the law which explains the dihybrid ratio.
(v) Give the possible combinations of gametes that can be obtained from F1 hybrid.
The diagram below is an experiment conducted to study a factor necessary for Photosynthesis. Observe the diagrams and then answer the following questions:
(i) What is the aim of the experiment?
(ii) Name the test performed on the leaf and the solution used for the test.
(iii) What type of leaf was used for the experiment? Give an example.
(iv) What is the expected result of the above test on the parts labelled A and B?
(v) Give a balanced chemical equation to represent the process of Photosynthesis.
The diagram given below show the cross section of two kinds of blood vessels:
(i) Identify the blood vessels A and B. In each case give a reason to support your answer.
(ii) Name the parts numbered 1 and 2.
(iii) When are the sound "LUBB" and "DUP" produced during a heartbeat?
(iv) Name the blood vessel that:
- begins and ends in capillaries
- supplies blood to the walls of the heart.
Answer the following:
(i) Draw a well labelled diagram of a 'Neuron' and name the following parts
- Node of Ranvier
- Nissil granules
- Cyton
(ii) Name the part of the human brain which is concerned with the following :
- Seat of memory
- Coordinates muscular activity
(iii) Mention any three major activities of the WHO.