Genetics

DNA-coated metal particles (gold/tungsten) are accelerated into target cells using high pressure. Particles penetrate cell walls and membranes, delivering foreign DNA

Primary Application:

• Particularly effective for plant cells due to their rigid cell walls
• Widely used in crop genetic engineering (e.g., Bt cotton, Golden Rice)

Thus, the correct option is D: Plant cells. This method revolutionized plant genetic engineering by enabling direct gene transfer into intact plant tissues.

To correctly match the terms in Column I with their definitions in Column II:

• Aneuploidy: This refers to the loss or gain of individual chromosomes, leading to an abnormal chromosome number.
• Monoploidy: This condition is characterized by having a single set of chromosomes (haploid), which is common in certain organisms like male bees.​
• Polyploidy: This involves an increase in the entire set of chromosomes, resulting in multiple sets beyond the diploid number.​
• Diploidy: This denotes having two sets of chromosomes, which is the standard chromosome number in most somatic cells of animals and plants.​

Thus, the correct matching is:​

Aneuploidy → q. Loss or gain of a chromosome
Monoploidy → s. A single set of chromosomes
Polyploidy → p. Increase in whole set of chromosomes
Diploidy → r. Two sets of chromosomes

Therefore, the correct answer is (C) : 1-q, 2-s, 3-p, 4-r.

In pedigree charts, the following symbols are standard: 

• Circle: Female
• Square: Male
• Shaded/Filled-in Shape: Indicates an affected individual (has the trait or condition being studied)
• Unshaded/Empty Shape: Indicates an unaffected individual

Therefore, an affected male would be represented by a shaded (filled-in) square.

Based on this, the correct answer is

A mule is the result of Interspecific hybridization.

(A) Out-crossing - Incorrect: Refers to breeding within the same species but unrelated individuals.

(B) Cross-breeding - Incorrect: Typically denotes breeding different breeds of the same species.

(C) Interspecific hybridization - Correct: Mules result from crossing horse (Equus caballus) and donkey (Equus asinus).

(D) Out-breeding - Incorrect: General term for avoiding inbreeding, not specific to hybrid crosses.

The correct answer is (C) Interspecific hybridization, producing this sterile hybrid of different Equus species.

Griffith's experiment demonstrated bacterial transformation. The correct representations are:

P. R strain → Inject into mice → Mice die - Incorrect: The non-virulent R strain alone cannot kill mice.

Q. S strain (Heat killed) → Injected into mice → Mice die - Incorrect: Heat-killed S strain alone cannot kill mice.

R. R strain → Inject into mice → Mice live - Correct: This was Griffith's control experiment showing R strain is non-lethal.

The correct answer is (B) R only, as this was the only completely accurate representation among the options given.