CSIR NET Life Sciences Mock Test IV

1.A DNA sequence, which is homologous to active gene, but not having any function

a. Intron

b. Interrupted sequences

c. Pseudogenes

d. Non coding repeats

2.Which of the following statement is true?

A. Satellite DNA is a part of chromosome localized to centromere only

B. Satellite DNA was discovered as disitinct band on agarose gel

C.Satellite DNA contains different base composition from rest other DNA sequences

D. All repititive DNA are a part of satellite DNA.

a. Only A

b. Only C

c. Only D

d. Both A and D

3. Around which prehsitoric time scale, homo sapiens evolved from previous species?

a. Pleistocene epoch

b. Eocene epoch

c. Oligocene epoch

d. Jurassic period

4. Bat use echolocation to locate the prey. The right ear of the bat picked up the wave slightly before being recognized by the left ear. This is interepted as

a. The prey is on right side

b. The prey is on left side

c. The prey is moving

d. The prey is on left side and bat is moving over it.

5. In non-human primates, the dominant male shows

A. More ability to capture prey

B. Polygynous

C. Parental care

a. Only B

b. Only c

c. Both A and B

d. All the above

6. The phenotype is governed by bot genotype and environment. Sometimes we find penotype is not inheritable and is prduced by organism exposed to a particular environment. This is due to

a. Pleotropy

b. Phenocopy

c. Psedogenes

d. Complementation

7. What is the minimum number of transesterificatioreactions required to splice out an intron from an mRNA transcript?

a. 1

b. 2

c. 3

d. 4

8. Which of the following processes allows activation of transcription by changing the accessibility of chromatin to transcription factors?

a. Extensive methylation of DNA

b. Binding of protamines to DNA

c. Action of ATPase chromatin remodeling complexes

d. Formation of a Barr body

e. Deacetylation of histones

9. Rifampicin is an important antibiotic used to treat tuberculosis, as well as other mycobacterial diseases. Some strains of Mycobacterium tuberculosis, are resistant to rifampicin, these strain become resistant by which of the following mechanisms?

a.Mutations in the MDR-type ABC transporter, which pumps the drug out of the Mycobacterium.

b. By production of rifamycin oxidase (RO).

c. Mutations that alter rpoB gene, involved in synthesis of β subunit of RNA polymerase.

d. Mutations in the sigma (σ) subunit of RNA polymerase

10. E. coli cells are growing in medium containing lactose but no glucose. A mutation is introduced such that it prevents binding of CRP to its binding site near the lac promoter. What will be the consequence of such type of mutation?

a. When glucose is introduced in the medium, the cells will not be able to utilize glucose.

b. The lac operon will be constitutively expressed irrespective of the concentration of glucose in the external medium.

c. The lac operons expression will decrease irrespective of the concentration of lactose in the surrounding medium.

d. The lac operons expression will be halted when glucose concentration is high.