MCAER PG CET 2026 BOTANY AND GENETICS AND PLANT BREEDING

 

MCAER PG CET 2026

Botany, Genetics & Plant Breeding

Time Left: 100s

Questions: 10

1. In a multi-allelic system, if a gene has 5 alleles, how many possible genotypes can be formed in a diploid population?

5 10 15 25

Answer: C (15). Formula: $n(n+1)/2$. So, $5(6)/2 = 15$.

2. [PYQ 2021] Which of the following is an example of an Allopolyploid derived from the cross of Triticum turgidum and Secale cereale?

Raphanobrassica Triticale Gossypium hirsutum Nicotiana tabacum

Answer: B (Triticale). Triticale is the first man-made cereal, an alloploid between wheat and rye.

3. The term "Genetic Load" refers to the existence of deleterious genes in a population. Who coined this term?

H.J. Muller Sewall Wright G.H. Hardy J.B.S. Haldane

Answer: A (H.J. Muller). Coined in 1950 to describe the reduction in fitness due to mutations.

4. In C4 plants, the first stable product of CO2 fixation is Oxaloacetate, which occurs in:

Bundle Sheath Cells Mesophyll Cells Guard Cells Phloem Sieve Tubes

Answer: B (Mesophyll Cells). PEP carboxylase fixes CO2 in mesophyll cells to form OAA.

5. [PYQ 2023] The 'Wobble Hypothesis' explains the degeneracy of the genetic code. Which position of the codon shows 'wobbling'?

First base Second base Third base All three bases

Answer: C (Third base). The 3' base of the mRNA codon allows non-standard pairing.

6. A plant with genotype AaBbCc is self-pollinated. What is the probability of obtaining an offspring with genotype aabbcc?

1/16 1/32 1/64 1/8

Answer: C (1/64). Calculated as $(1/4)^3$ because each locus has a 1/4 chance for recessive homozygosity.

7. Which breeding method is most suitable for transferring a disease-resistant gene from a wild relative to a high-yielding variety?

Mass Selection Backcross Method Pure line Selection Bulk Method

Answer: B (Backcross). Ideal for transferring specific traits (monogenic) into an existing elite line.

8. "Synteny" refers to:

Genes located on different chromosomes Genes located on the same chromosome Deletion of a chromosomal segment Doubling of the genome

Answer: B (Genes on same chromosome). Synteny describes the physical co-localization of genetic loci.

9. The phenomenon where one gene interferes with the phenotypic expression of another non-allelic gene is:

Dominance Epistasis Co-dominance Pleiotropy

Answer: B (Epistasis). It involves gene interaction at different loci.

10. In Plant Breeding, 'GCA' (General Combining Ability) is primarily evaluated using:

Diallel Cross Top Cross Poly-cross All of the above

Answer: D (All of the above). While Top cross is simplest for GCA, Diallel and Polycross also provide GCA estimates.

Review the explanations above to improve your preparation.