131.

Following are the main types of defense employed by prey species against predators.

Types of defense : Chemical with aposematic coloration (A); Cryptic coloration (B); Batesian mimicry (C); Intimidation display (D)

Prey species : Grasshoppers and seahorses (i); Hoverflies and wasps (ii); Bombardier battles, ladybird beetles, many butterflies (iii); Frilled lizard, Porcupine fish (iv)

Which on of the following combinations is correct?

• A - (i);B - (iii); C - (ii); D - (iv)

• A - (iv);B - (ii); C - (i); D - (iii)

• A - (iii);B - (i); C - (ii); D - (iv)

• A - (ii);B - (iii); C - (i); D - (iv)

Following is the list of some important events in the history of life and the names of the epochs of Cenozoic era.

Events-

A. Angiosperm dominance increase; continued radiation of most present day mammalian orders.

B. Major radiation of mammals, birds and pollinating insects.

C. Origins of man primate groups.

D. Origin of genus Homo.

E. Appearance of bipedal human ancestors.

F. Continued radiation of mammals and angiosperms, earliest direct human ancestors.

Epochs - 

(i) Paleocene; (ii) Pleistocene; (iii) Oligocene; (iv) Pliocene; (v) Eocene; (vi) Miocene

Which one of the following is the correct match of events with the epochs?

• A - (v); B - (ii); C - (i); D - (iii); E - (iv); F - (vi)

• A - (vi); B - (i); C - (ii); D - (iv); E - (iii); F - (v)

• A - (v); B - (i); C - (iii); D - (ii); E - (iv); F - (vi)

• A - (iv); B - (i); C - (ii); D - (iii); E - (v); F - (vi)

In the evolutionary tree given below, terms A, B, C, D, and E, represent respectively

• Homo erectus, Homo heidlebergensis, Neanderthal, Denisovan and Homo sapiens.

• Homo heidelbergensis, Homo erectus, Denisovan, Neanderthal and Homo sapiens.

• Homo erectus, Homo heidelbergensis, Denisovan, Neanderthal and Homo sapiens.

• Homo heidelbergensis, Homo sapiens, Denisovan, Neanderthal, and Homo erectus.

In transgenic mice, the orientation and location of the loxP sites determine whether Cre recombinase induces a deletion, an inversion or a chromosomal translocation. If a researcher wants to put the loxP sites in such a manner that only inversion will take place, which one of the following construct best justifies their intention. Gene X is the target gene.

Factor IX is essential for blood clotting. Deficiency of Factor IX could be corrected by delivering factor IX gene using viral vectors. In an experiment the gene for Factor IX was cloned appropriately into Adenovirus (AV), Adeno-associated virus (AAV) and Retrovirus (RV). Retrovirus integrate the gene into the dividing cells. AAV integrates partially into non-dividing cells. AV does not integrate the gene but tranfects both dividing and non-dividing cells.

Following expression profile for Factor IX was observed when the three vectors were injected intra-muscularly into three groups of experimental mice.

Which one of the following outcomes is corrcet?

• a by RV; b by AV; c by AAV

• a by AV; b by AAV; c by RV

• a by AAV; b by RV; c by AV

• a by AV; b by RV; c by AAV

The following genes have been genetically engineered to develop herbicide resistance in plants:

A. Resistance to glyphosate using the 5-enolpyruvyl shikimate-3-phosphate synthase gene.

B. Bialaphos resistance using the bar gene.

C. Sulfonyl urea resistance using the acetolactate synthase gene.

D. Atrazine resistance using the glutathione S-transferase gene.

In which of the above two case the mechanism is based on abolition of herbicide binding to the enzyme?

• A and D

• B and C

• C and D

• A and C

Somatic embryogenesis is an important exercise in micropropogation and genetic engineering of plants. The following steps are considered as critical for achieving somatic embryogenesis:

A. Reducing the concentration of sucrose in the medium by half.

B. Addition of the hormone, 2, 4-dichlorophenoxyacetic acid, to induce somatic embryos.

C. Reduce agar concentration to 0.6% (w/v).

D. Use maltose in place of sucrose as a carbon source.

Which one of the following combinations is correct?

• A and C

• B and D

• A and B

• C and D

A gene from genomic library is screened by using hybridization technique. After hybridizing the probe, usually a stringent washing step is given. The following statements are given to explain the stringent washing step:

A. Stringent washing takes care of removing unincorporated and non-specifically hybridized probe molecules.

B. Stringent washing is done in solution having high salt concentration and lower temoerature.

C. Stringent washing is done in solution having low salt concentration keeping higher temperature.

D. Salt present in washing solution supports hybrids to stay intact by shielding the interference of water molecules.

E. Salt reacts with DNA molecules and allows easy dissociation of hybrids.

F. Stability of hybrid is directly proportional to the temperature.

Which combination of the above statements is most appropriate for stringent washing step?

• A, B and D

• A, C and D

• A, B and F

• C, E and F

For the aquaculture of Indian Major carps several techniques are used. Which one of the following techniques is NOT used for this purpose:

• Induced breeding

• Selective breeding

• Inbreeding

• Composite fish farming

A student, while constructing knock-out mice, isolated mouse embryonic stem cells and introduced an engineered DNA into the cells. However, none of the mice were transgenic. On checking the cells containing DNA construct, he found that he had made a mistake in constructing the DNA since the cells were resistant to gancyclovir but sensitive to G418. Which one of the following constructs had the designed?