Biology

Genetics and Plant Breeding

1,177 Questions

Genetics and Plant Breeding explores the principles of heredity, chromosomal inheritance, and hybridization techniques. It includes key concepts like Mendelian genetics, gene linkage, and polygenic inheritance. This topic is essential for students tackling advanced biology or botany sections in competitive examinations.

Mendelian InheritanceChromosome TheoryGene LinkagePolygenic InheritancePlant HybridizationPopulation Genetics Equilibrium

Genetics and Plant Breeding Questions

Multiple choice

Crossing between genetically dissimilar plant varieties is known as

  1. cropping

  2. hybridization

  3. tissue culture

  4. insemination
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hybridization is the process of crossing genetically different plant varieties to combine desirable traits from both parents. Cropping refers to growing systems, tissue culture involves growing cells artificially, and insemination is an animal breeding term.

Multiple choice

In reciprocal recombination,

  1. recombination occurs between two genes with high sequence identity

  2. recombination occurs between two DNA sequences with little or no sequence identity

  3. a symmetrical exchange of genetic material occurs between two DNA strands

  4. specialized nucleotide sequences exhibiting some degree of target site specificity are moved between non-homologous sites within a genome

  5. offspring are produced with combinations of traits that differ from those found in either parent
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In site-specific recombination, specialized nucleotide sequences exhibiting some degree of target site specificity are moved between non-homologous sites within a genome.

Multiple choice

Consider the following statements:

(1) Genome is a complete set of an organism's heredity information. (2) Triticale, a crop species has been developed through hybridisation between Wheat and Rye.

Which of the given statements is/are correct?

  1. Only (1)

  2. Only (2)

  3. Both (1) and (2)

  4. Neither (1) nor (2)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statement (1) is correct. A genome is the complete collection of hereditary information for an individual organism. Statement (2) is also correct. Triticale is a crop species resulting from a plant breeder's cross between wheat (Triticum) and rye (Secale).

Multiple choice

Which of the following is/are the reason(s) that Mendel used pea plant in his experiments? (a) Pea plant is a biennial plant. (b) Easily identifiable and contrasting characters are present in pea plants. (c) Cross pollination can be induced in pea plants. (d) A single pea pod has many seeds in it.

  1. Only (a), (b) and (c)

  2. Only (a) and (d)

  3. Only (b) and (c)

  4. Only (b), (c) and (d)

  5. Only (c) and (d)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

All three are correct. (d) is incorrect. A single pea pod has many seeds in it. This is not the reason due to which Mendel used pea plant in his experiments.

Multiple choice

Mendel studied seven contrasting characters for his breeding experiment with Pisum sativum. Which of the following characters did he identify as dominant characters?

  1. Yellow colour of seeds, white colour of flower, inflated seed pods

  2. Green colour of unripe pods, axillary position of flowers, round shape of seeds

  3. Tall stem, constricted seed pods, terminal position of flowers

  4. Green colour of seeds, purple colour of flower, inflated seed pods

  5. Yellow colour of unripe pods, axillary position of flowers, round shape of seeds
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Green colour of unripe pods: Dominant Axillary position of flowers: Dominant Round shape of seeds: Dominant

Multiple choice

As a consequence of accidental conception, which among the following takes place?

  1. Almost all the progenies will have a unique combination of alleles.

  2. Most of the offsprings in the same family have the same combination of alleles.

  3. There will be no randomness in the inheritance of alleles in the offsprings from parents.

  4. Almost all the progenies will have a identical combination of alleles.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Siblings usually share many genetic traits, but they do not have identical sets of alleles unless they are monozygotic (i.e. identical) twins.

Multiple choice

Which of the following principles cannot be depicted by a monohybrid cross?

  1. Law of dominance

  2. Law of segregation

  3. Law of independent assortment

  4. Incomplete dominance
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Law of independent assortment states that when two pairs of independent alleles enter into combination in the F2 generation, they exhibit independent dominant effects. It means that during the formation of gametes, the law of segregation operates but the factors assort themselves independently at random and freely. So, for explaining this principle a monohybrid cross will be insufficient. We will need a dihybrid cross to depict this. Thus, this is the correct answer.