Previous Year Questions

QUESTION ID:2

Agrobacterium tumefaciens, also known as natural genetic engineers, causes crown-gall disease in plants. However, when the same bacteria are used to raise transgenic plants with improved agronomic traits, no such tumor (disease) is observed. This is due to:
A. Vir D2 gene is mutated in Ti plasmid.
B. Disarmed Ti plasmid is generally used.
C. Heat-shock during transformation destroys virulence.
D. Oncogenes have been removed.
Which one of the following combination of above statements is correct?

QUESTION ID:3

Locus control region (LCR) lies far upstream from the gene cluster and is required for the appropriate expression of each gene in cluster. LCR regulates expression of globin genes in the cluster through the following ways.
A. LCR interacts with promoters of individual genes by DNA looping through DNA-binding proteins.
B. The LCR-bound proteins attract chromatin-remodeling complexes including histone-modifying enzymes and components of the transcription machinery.
C. LCR acts as an enhancer for global regulation of gene cluster and does not regulate individual genes.
D. LCR participates in covering inactive chromatin to active chromatin around the gene cluster.
Choose the correct set of combinations.

QUESTION ID:4

A student wrote following statements regarding comparison of Restriction Fragment Length Polymorphism
(RFLP), Random Amplified Polymorphic DNA (RAPD), Amplified Fragment Length Polymorphism (AFLP) and Simple Sequence Repeats (SSRs) techniques used for generating molecular markers in plants:
A. All these techniques can be used for fingerprinting.
B. Detection of allelic variation can be achieved only by RFLP and SSRs.
C. Use of radioisotopes is required in RFLP and RAPD only.
D. Polymerase chain reaction is required for all the techniques.
Which one of the following combination of above statements is correct?

QUESTION ID:5

In order to clone an eukaryotic gene in pBR322 plasmid vector, the desired DNA fragment was produced by PstI cleavage and incubated with PstI digested pRR322 (PstI cleavage site lies within the ampicillin resistant gene) and ligated. Mixtures of ligated cells were used to transform E. coli and plasmid containing bacteria were selected by their growth in tetracycline containing medium. Which type of plasmid/s will be found?

QUESTION ID:6

During apoptosis, phosphatidyl serine (PS) usually present in the inner leaflet of the plasma membrane flips to the outer membrane. Annexin V is a protein that binds to PS, Using this as a tool, we identifiy the apoptic cells from necrotic and normal cell populations by FACS using FITC-tagged Annexin V. Propidium iodide (PI) is used to stain the nucleus which generally identifies necrotic and late apoptic cells. In which
area of the plot you should get early apoptic cells by FACS analysis?

QUESTION ID:7

The muscle tone was increased after electrolytic lesion of the caudate nucleus in a cat. The muscle tone decreased within seven days. The following explanations were given by the researcher.
A. The functional recovery was due to plastic changes of nervous system.
B. The brain tissue surrounding the lesioned area was nonfunctional due to circulatory insufficiency immediately after surgery which led to the greater functional loss.
C. The circulatory status in surrounding tissue recovered with time resulting in partial functional recovery.
D. The degenerating nerve fibres were regenerated which underlie functional recovery.
Which one of the following is correct?

QUESTION ID:8

A fluorophore when transferred from solvent A to solvent B results in an increase in the number of vibrational states in the ground state without any change in the mean energies of either the ground or excited state. What would be the change seen in the fluorophore’s emission spectrum?

QUESTION ID:9

You wish to localise a given gene product at subcellular levels following immunofluoroscence staining. Routine microscopy could not resolve whether the gene product is localized inside the nucleus or on the nuclear membrane.
Which of the following will resolve this unambiguously?
A. Sectioning of cell followed by phase contrast microscopy.
B. A simulation of 3D picture following confocal microscopy.
C. Optical sectioning and observing each section.
D. Freeze fracturing followed by Scanning Electron Microscopy.

QUESTION ID:10

The Triver-Willard hypothesis states that the physiological state of a female can bias the sex ratio of offspring. In an experiment in the bird species a group of females were fed a diet 30% lower in calories than the control females. After allowing both the groups to mate and breed freely, the offspring of control 1 group were 22 males and 18 females. The diet restricted females laid a total of 40 eggs. What should be the minimum deviation from the control to conclude that they have significantly female biased offspring sex ratio. (Chi sq [0.05] df =1 is 3.84)