Consider the following statements regarding centromere and choose the correct answer:<br>1. The position of the centromere is constant for a particular chromosome<br>2. The structure and function of the centromere are different from that of the rest of the chromosome<br>3. During division the centromere is functional, while the rest of the chromosome is genetically inactive<br>4. The position of the centromere varies in different chromosomes

Consider the following statements with regard to the functions of the centromere in the chromosome.
1. Centromeres are the centres of movement of the chromatids or chromosomes during anaphase separation.
2. Acentric chromosomes lack the capacity to segregate in a regular fashion.
3. Crosing-over in one arm of a metacentric chromosome does not affect the crossing over in the arm of the same chromosome.
Which of the statements given above are correct?

A

1, 2 and 3

B

1 and 2

C

2 and 3

D

1 and 3

Consider the following statements.
1. Human beings have 23 pairs of chromosomes.
2. Sex chromosome in human male are named XY.
3. Chromosomes are best seen in metaphase.
Which of the statements given above is/are false about chromosomes?

A

1 and 2

B

2 and 3

C

1, 2 and 3

D

None of the above

Consider the following statements regarding supernumerary chromosomes and choose the correct answer:
1. They are not homologous with any of the normal chromosomes
2. They form synapses among themselves
3. They are generally smaller than normal chromosomes
4. They are found more commonly in plants than in animals

A

Only 2, 3 and 4 are correct

B

Only 1, 3 and 4 are correct

C

1, 2, 3 and 4 are correct

D

None of the above

Consider the following statements regarding the theory of linkage and choose the correct answer:
1. Genes are arranged in a linear fashion in the chromosomes
2. Genes that show linkage are situated in the chromosome
3. Linked genes remain in their original combination during the course of inheritance
4. The genes which are widely separated show strong linkage, while those closely located, have more chances to get separated by crossing over

A

Only 1, 2 and 3 are true

B

Only 2, 3 and 4 are true

C

Only 1, 3 and 4 are true

D

Only 3 and 4 are true

Consider the following statements regarding the pachytene substage of prophase I during meiosis and choose the correct answer:
1. Pachytene is said to begin when synapsis is completed
2. During pachytene the chromosomes are associated in bivalents or tetrads
3. Shortening and thickening of the chromosomes takes place due to longitudinal contraction
4. Exchange of groups of genes takes place as a result of crossing over

A

Only 1 and 2 are correct

B

Only 1, 2 and 3 are correct

C

Only 2, 3 and 4 are correct

D

1, 2, 3 and 4 are correct

Consider the following statements regarding evolution and choose the correct answer:
1. Basically, evolution is the result of the differential survival in each generation of the progeny of the individuals with certain special characteristics
2. The organization of genes in chromosomes and the behaviour of these during cell division do not affect the mechanisms of evolution
3. Due to sexual reproduction there is a tremendous increase in variability
4. Differential survival is always partly due to capacity to adopt to the physical environment

A

Only 1, 2 and 3 are true

B

Only 2, 3 and 4 are true

C

Only 1, 3 and 4 are true

D

Only 1, 2 and 4 are true

Consider the Assertion (A) and Reason (R) and select the correct answer:
Assertion (A) If one premise is particular, the conclusion must be particular.
Reason (R) (i) An affirmative particular has no distributed terms, and a negative particular has an only one.
(ii) The premises cannot both be particular and thus must differ in quantity.

A

A and R both are true but R (i) and (ii) correct explanations of A

B

A and R both are true but R (i) is correct explanation of A

C

A and R both are true but R (ii) is a correct explanation of A

D

A is true, but R (i) and (ii) are incorrect explanations of A

Consider the following statements regarding satellite DNA and choose the correct answer:
1. Satellite or Repetitive DNA consists of short identical genes which are repeated in tandem several hundred or thousand times
2. Such DNA is found in the region of the chromosome adjacent to the centromere
3. It is easy to separate repetitive DNA by ultracentrifugation

A

Only 1 and 2 are true

B

Only 2 and 3 are true

C

Only 1 and 3 are true

D

1, 2 and 3 are true

Assertion (A) Human beings have 23 pair of chromosomes, one of which is the sex chromosomes and the remaining are 22 autosomes. The X-linked disease are related to mutation on a sex chromosomes.
Reason (R) Colour blindness results from a mutation in X-chromosome.

A

Both A and R are true and R is the correct explanation of A

B

Both A and R are true, but R is not the correct explanation of A

C

A is true, but R is false

D

A is false, but R is true

Two forest officials in their respective division were involved in the harvesting of tendu leave. One division had an average output of 21 tons from a hectares and other division, which had 12 hectares of land less, dedicated to tendu leaves, got 25 tons of tendu from a hectare. As a result, the second division harvested 300 tons of tendu leaves more than the first. How many tons of tendu leaves did the first division harvest.

A

3150

B

3450

C

3500

D

3600

E

None of these