CSIR NET Life Sciences Mock Test II

Questions:
1. During electrophoresis, ethidium bromide is used as a stain to visualize DNA. Which of the following is doesn’t occur when it binds to the DNA

(1) It unwinds the DNA

(2) t increases the normal rotation per bp in DNA

(3) it increases the helical pitch

(4) Its fluorescence increases after intercalation

2. Which of the following is not true about the embryogenesis of Drosophila?

(1) A cell signaling molecule controls nuclear transport of the dorsal protein

(2) Loss of Hox gene causes the appearance of a normal appendage at an inappropriate body position

(3) Bicoid mRNA is located on the posterior pole and nanos mRNA is located on the anterior pole during fertilization

(4) Nanos are RNA binding proteinsosition

3.Which of the following is true for RecA Proteins?

(P) Ability to polymerize single strands

(Q) Ability to incorporate DNA into filaments

(R) The product of RecA sponsored reaction of a circular DNA molecule will be a chi (x) structure

(S) 5’GCT GG TGG3’ sequence stimulates recombination in its vicinity

(1) Q, R

(2) R, S

(3) P, Q, R

(4) P, Q, R, S

4.An aliquot of a solution containing a light absorbing substance at a concentration of 5 gdm–3 was placed in a 2 cm light path cuvette. The cuvette was placed in a spectrophotometer and a beam of light of wave length l was passed through the cuvette containing the solution. If the absorbance of the solution is 0.0969 then calculate the molar extinction coefficient in (mol dm–3) cm–1. (molecular weight of substance is 580).

(1) 9.7 × 10-3

(2) 5.62

(3) 1.6 × 10-5

(4) None

5.Choose the mismatch of the cell line and its origin

(1) Pt k1 – rat kangaroo – epithelial cell

((2) COS – monkey – kidney

(3) SP2 – mouse – plasma cell

(4) L6 - fibroblast – rat

6.Lectins are used as probe to purify specific biomolecules of Jacalin is used in an experiment, which of the following suggests the interaction occurring and the corresponding antibody which can be purified

(1) Protein – protein interaction, IgG

(2) Protein – mannose interaction, IgA

(3) Protein – glucose interaction, IgG

(4) Protein – galactose interaction, IGa

7.Which of the following contributes to cell signaling in bacteria, plants and mammals?

(1) Phosphatidylinositol kinesis

(2) Trimesic G proteins

(3) 2 component His kinases

(4) None

8.In prokaryotes, each subunit of DNA polymerase III has different function which of the following gene transcribes a subunit which interacts with the SSB in (E.coli)

(1) hol C

(2) pol C

(3) dna X

(4) mut D

9.The proteins synthesized in translation are subjected to post - translational modification. During the formation of collagen, the amino acids proline and lysin are respectively converted to hydroxylproline and hydroxylysin. This hydroxylation occurs in the ____(x) and requires ___(Y).

(1) X - Golgi apparatus, and Y - Vit C

(2) X - mitochondria and Y - vit B1

(3) X - Endoplasmic reticulum and Y - Vit C

(4) X - ribosome and Y - Vit. C.

10.Which of the following is not chemotropic nitrogen fixing bacteria?

(1) Chromatium venous

(2) Bacillus macerans

(3) Xanthobacter autotrophicus

(4) Enterobacter aerogenes

11.Which of the following is not correctly matched?

(1) Aminoglycoside antibiotics –– inhibitors of protein synthesis in bacteria

(2) Penicillin –– inhibit the enzymes catalyzing the transpeptidation reaction

(3) Sulfonamides –– inhibit protein synthesis

(4) All are correctly matched

12.Which of the following statements are true regarding Agrobacterium?

(1) All genes are not transcribed during vegetative growth

(2) Some chromosomal genes contribute to virulence

(3) T DNA region contains a 25 bp conserved region only in case of Ti plasmids.

(4) Octapine catabolism is controlled by noc loci

13.Which of the following is false for photorespiration?

(1) It gives an idea about evolution of plants

(2) It cannot occur in very low O2 concentration

(3) It occurs in green cell of petunia

(4) Release of CO2 occurs from C1 of glycolate

14.After the formation of primitive streak, the trophoblasts around the anterior and posterior margins of embryonic disc rise up as folds which grow over and enclose the embryo from above. The outer wall of each fold is called _____(X) and inner one _____ (Y).

Choose the correct option for X and Y.

(1) X - chorion and Y - amnion

(2) X - allantois and Y - chorion

(3) X - amnion and Y - Yolk sac

(4) X - amnion and Y – allantois

15.Match the following.

(P) Tricuspid valve (I) at the entrance to the pulmonary trunk.

(Q) Mitral value (II) Right atrio - ventricular valve

(R) Semilunar Value (III) at the entrance to the aorta

(IV) Left - atrio – ventricular

     P       Q     R

(1) IV      II      I

(2) III      IV     II

(3) II       IV    III

(4) I        III    IV