MCAER PG CET 2026 BOTANY AND GENETICS PLANT BREEDING

 

MCAER PG CET 2026

Botany, Genetics & Plant Breeding - Advanced Mock

Time Remaining: 100s

1. Which of the following refers to the "Baldwin effect" in evolutionary genetics?

Genetic drift in small island populations

Learned behaviors becoming evolutionarily ingrained via natural selection

The loss of fitness due to inbreeding depression

Rapid speciation due to polyploidy

Correct Answer: B. The Baldwin effect suggests that the ability to learn new behaviors can influence the rate and direction of evolutionary change.

2. [PYQ 2021] In a nullisomic plant, the chromosome number is represented by:

2n + 1

2n - 1

2n - 2

2n + 2

Correct Answer: C. Nullisomy is the loss of a pair of homologous chromosomes (2n-2).

3. What is the genetic ratio of a duplicate dominant epistasis (e.g., in shepherd's purse fruit shape)?

9:7

15:1

13:3

9:3:4

Correct Answer: B. 15:1 occurs when a dominant allele at either of two loci can produce the same phenotype.

4. The phenomenon of "Paracentric Inversion" results in which of the following during meiosis?

Inclusion of the centromere in the inverted segment

Formation of dicentric bridge and acentric fragment

Change in the arm ratio of the chromosome

No crossover suppression

Correct Answer: B. Paracentric inversions (not involving centromere) produce dicentric bridges and acentric fragments during crossover.

5. [PYQ 2023] Which breeding method is most suitable for transferring a single qualitative trait into an otherwise elite cultivar?

Pedigree Method

Mass Selection

Backcross Method

Bulk Method

Correct Answer: C. The backcross method is the gold standard for introgressing specific genes into a recurrent parent.

6. The term "Gynogenesis" refers to:

Development of embryo from an unfertilized egg

Development of embryo from male gametes only

Development of fruit without seeds

Fusion of two female nuclei

Correct Answer: A. In Gynogenesis, the embryo contains only the maternal genome.

7. In DNA replication, what is the role of 'Topoisomerase'?

Joining Okazaki fragments

Unwinding the DNA helix

Relieving torsional strain (supercoiling)

Adding RNA primers

Correct Answer: C. Topoisomerase prevents DNA from becoming tangled during unwinding.

8. Which of the following is an example of an Allopolyploid?

Autotriploid Banana

Raphanobrassica

Tetraploid Watermelon

Doob grass

Correct Answer: B. Raphanobrassica is a classic intergeneric allopolyploid (Radish x Cabbage).

9. The phenomenon where one gene influences multiple, seemingly unrelated phenotypic traits is:

Epistasis

Pleiotropy

Polygeny

Co-dominance

Correct Answer: B. Pleiotropy is seen in cases like sickle cell anemia or certain pigment genes in plants.

10. "Pure Line Theory" was proposed by Johannsen (1903) working on which crop?

Pea

Princess Bean

Maize

Wheat

Correct Answer: B. Johannsen's work on *Phaseolus vulgaris* (Princess Bean) established that selection within a pure line is ineffective.

Quiz Results

Review the explanations below each question for better understanding.