Dendritic cells (DC) from BALB/c mice were treated with 1L-10or IFN-γ. Similarly, dendritic cells from β2-microglobulin-deficient mice were also treated with 1L-10 or with IFN-γ. These cells were co-cultured with CD8⁺ T cells from hen egg lysozyme (HEL)-specific T cell receptor transgenic mice in the presence of the HEL peptide. five days later, CD8⁺ T cells were assayed for target cell lysis. Which one of the following combinations will have the highest target cytotoxicity?

• DC (BALB/c)^IL-10 × CD8⁺T

• DC (BALB/c)^IFN-γ × CD8^+T

• DC (β2-microglobulin-deficient)^IL-10 × CD8⁺T

• DC (β2-microglobulin-deficient)^IFN-γ × CD8⁺T

A novel enzyme was identified in humans. The following approaches are available to identify the chromosome on which the gene encoding the enzyme is present:

(A) Suppress the activity of enzyme by RNAi.

(B) Identify polymorphism in the population and carry out pedigree analysis to study its inheritance.

(C) Purify the enzyme, decipher its amino acid sequence, predict its DNA sequence and search for its presence in the available human genome sequence.

(D) Create chromosome addition lines by making somatic hybrids between human and mouse cells, identify lines showing the enzyme and the human chromosome present in it.

Which of the above approaches can be used?

• (A) or (B)

• (B) or (C)

• (C) or (D)

• (A) or (C)

Plasmids are self-replicating small circular DNA elements in bacterial cells that can be said to have stable symbiotic existence with the host cell. They often carry genes useful to the host. Which of the following is a potential threat to the evolution and stability of the symbiotic coexistence?

• 'Copy-up' mutations that increase the rate of plasmid replication per host cell cycle.

• Reversible integration of plasmid DNA into the host DNA.

• Transfer of plasmids to new cells by conjugation.

• Spontaneous curing of plasmids in a small proportion of host cells.

Choose the correct sequence of events in a next-generation sequencing technology-bases whole genome sequencing project.

• DNA extraction → shearing → library preparation → sequencing → assembly → finishing → annotation → submission to Genbank.

• DNA extraction → library preparation → sequencing → assembly → annotation → finishing → submission to Genbank

• DNA extraction → shearing → adapter ligation → library amplification → sequencing → assembly → finishing → annotation → submission to Genbank.

• DNA extraction → adapter ligation → library amplification → shearing → sequencing → finishing → assembly → annotation → submission to Genbank.

The frequency distribution of tree heights in two forest areas with different annual rainfall are given

Which of the following statistical analysis will you choose to test whether rainfall has an effect on tree heights?

• t test for comparison of means.

• A non-parametric comparison of the two groups.

• Correlation analysis of rainfall and mean tree heights.

• Regression of tree heights on rainfall.

166.

Two species of plants were sampled in 32 quadrants in a forest. The mean and variance for the occurrence of species 1 were 16.2 and 48 and species 2 were 3.6 and 3.2 respectively. Which of the following statements about the distribution of the two species in these quadrats is supported by these findings?

• Both species are distributed randomly.

• Species 1 is distributed randomly and species 2 is clustered.

• Species 1 is clustered and species 2 is distributed randomly.

• Both species are clustered.

A cartwheel rolls along a straight line. If the distance covered is equal to the diameter of the wheel, what is the angle through which the wheel has turned?

• 90°

• between 90° and 120°

• between 120° and 150°

• between 150° and 180°

In a class of 10 students, 3 failed in History, 6 failed in Geography and 2 failed in both. How many passed in both the subjects?

• 1

• 2

• 7

• 0

As shown in the diagram above, a sphere is placed on the top of an incline. It rolls down the incline without slipping in exactly 50 turns. The radius of the sphere is

• $\left(\frac{5}{\mathrm{\pi }}\right)\mathrm{cm}$

• $\left(\frac{5}{\mathrm{\pi }}\right)\mathrm{m}$

• $\left(\frac{10}{\mathrm{\pi }}\right) \mathrm{cm}$

• 10 cm

A set of concentric circles if integer radii 1, 2, ...., N is shown in the figure above. An ant starts at point A₁, goes around the first circle, returns to A₁, moves to A₂, goes round the second circle, returns to A₂, moves to A₃ , and repeats this until it reaches A_N. the distance covered by the ant is

• N(N + 1)$\mathrm{\pi }$

• 2N$\mathrm{\pi }$ + N

• $\mathrm{\pi }$(N + 1) N + N - 1

• $\mathrm{\pi }$(N - 1) N + N - 1