Assuming a 1 : 1 sex ratio, what is the probability that three children from the same parents will consist of two daughters and one son?

• 0.375

• 0.125

• 0.675

• 0.75

In ‘TaqMan’ assay for detection of base substitutions (DNAvariant), probes (oligonucleotides) with fluorescent dyes at the 5’-end and a quencher at 3’-end are used. While the probe is intact, the proximity of the quencher reduces the fluorescence emitted by reporter dye. If the target sequences (wild type or the variant) are present, the probe anneals to the target sequence, down stream to one of the primers used for amplifying the DNA sequence flanking the position of the variants. For an assay two flanking PCR primers, two probes corresponding to the wild type and variant allele and labeled with two different reporter dyes and quencher were used. During extension the probe may be cleaved by the Taq-polymerase separating the reporter dye and the quencher. Three individuals were genotyped using this assay. Sample for individual I shows maximum fluorescence for the dye attached to the wild type probe, sample for individual II shows maximum fluorescence for the dye attached to variant probe and sample for individual III exhibits equal fluorescence for both the dyes. Which of the following statement is correct?

• Individual I is homozygous for the variant allele

• Individual II is homozygous for variant allele.  

• Individual II is homozygous for wild type allele.

• Individual III is homozygous for wild type allele.

Stem cell therapies are being used in regenerative medicine like forming new adult bone, which usually does not regrow to bridge wide gaps. Successful attempts have now been made in this area because the same paracrine and endocrine factors were found to be involved in both endochondral ossification and fracture repair. Few methods to achieve the above are given below:

A. Develop a collagen gel containing plasmids carrying the human parathyroid hormone gene and place in the gap between the ends of the broken leg.

B. Develop a gel matrix disc containing genetically modified stem cells to secrete BMP4 and VEGF-A and implant it at the site of the wound.

C. Make scaffolds of material that resemble normal extracellular matrix that could be molded to form the shape of a bone needed and seed them with bone marrow stem cell.

D. develop a collagen gel containing plasmids carrying the human bone marrow cells and place them between the ends of the bones.

Which of the above methods would you employ to develop a new functional bone in patients with severely fractured bones?

• A and B

• A, B and C

• A and C

• C and D

54.

Cre/ lox P system is used by phage P1 to remove terminally redundant sequences that arise during packaging of the phage DNA. Cre-lox system can be used to create targeted deletions, insertions and inversion in genomes of transgenic animals and plants. Consider a series of genetic markers A to K. How should the Lox-P sites be positioned in order that Cre recombinase can create an inversion in the EFG segment relative to ABCD and HIJK?

• 

• 

• 

• 

The most important property of any microscope is its power of resolution, which is numerically equivalent to D, the minimum distance between two distinguishable objects. D depends on three parameters namely, the angular aperture, α, the refractive index, N, and wavelength, λ,of the incident light. Below are given few possible options to increase the resolution of the microscope.

A. Decrease the value of λ or increase either N or α to improve resolution.

B. Moving the objective lens closer to the specimen will decrease sin α and improve the resolution.

C. Using a medium with high refraction index between the specimen and the objective lens to improve the resolution.

D. Increase the wavelength of the incident light to improve the resolution.

Which of the following combination of above statements is correct?

• A and C

• B and C

• A and D

• C and D

T-cell proliferation in vivo is to be analyzed. The cells are labeled with CFSE (a fluroscent probe) and injected in CD86-deficient mice and BALB/ c mice along with the required antigens. Three days later, the cells are recovered and analyzed by flow cytometry. Which one of the following is logically correct?

In the following statement taken from a research paper, what does p in the parenthesis stand for?

“The mean temperature of this region now is significantly higher than the one 50 years ago (p < 0.05, t – test)”.

• Ratio of the mean temperatures of the two time periods tested.

• Probability of the error of rejecting a true null hypothesis.

• Probability of the error of accepting a false null hypotheis.

• Probability of the t-test being effective in detecting significant differences in the mean annual temperatures of the two time periods.   

A granite block of 2m × 5m × 3m size into 5cm thick slabs of 2 m × 5m size. These slabs are laid over a 2m wide pavement. What is the length of the pavement that can be covered with these slabs?

• 100 m

• 200 m

• 300 m

• 500 m

Which is the least among the following?

0.33^0.33, 0.44^0.44, ${\mathrm{\pi }}^{-1/\mathrm{\pi }}$, e^-1/e

• 0.33^0.33

• 0.44^0.44

• ${\mathrm{\pi }}^{-1/\mathrm{\pi }}$

• e^-1/e

What is the next number in this “see and tell” sequence?

1   11   21  1211   1112211    …….

• 312211

• 1112221

• 1112222

• 1112131