A disease is inherited by a child with a probability of $${1 \over 4}$$. In a family with two children, the probability that exactly one sibling is affected by this disease is

RNA is very much susceptible to hydrolysis in alkali because

A. It contains uracil residues in its structure

B. its 2'-OH group participate in intramolecular cleavage of phosphodiester backbone

C. Cleavage occurs in the glycosylic bonds of purine bases

D. Cleavage occurs in the glycosylic bonds of pyrimidine bases

Rho-dependent and rho-independent transcription termination mechanisms operate in prokaryotes. Rho independent termination mechanism involves

A. Binding of the rho protein upstream of the termination element

B. No protein factors and only RNA secondary structure and run of 'U's

C. Presence of UGA or UAA stop codons

D. Binding of accessory factors at termination signal

Determine the correctness or otherwise of the following Assertion (A) and the Reason (R).
Assertion: Cytoplasmic male sterility (cms) is invariably due to defect(s) in mitochondrial function.
Reason: cms can be overcome by pollinating a fertility restoring (Rf ) plant with pollen from a non cms plant.

A. Both (A) and (R) are true and (R) is the correct reason for (A)

B. Both (A) and (R) are true and (R) is not the correct reason for (A)

C. (A) is false but (R) is true

D. (A) is true but (R) is false

Mobile genetic elements present in human genome are
P. Long interspersed elements (LINEs)
Q. Short interspersed elements (SINEs)
R. P elements
S. IS elements

A. Q, R

B. P, Q

C. P, R

D. Q, S