Biology

Genetics and Plant Breeding

1,240 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

In peas, tall plant trait is dominant over dwarf. If a heterozygous for tall is crossed with one homozygous for dwarf, what will be the appearance of the offspring of a cross of F1?

  1. All tall

  2. All dwarf

  3. 50% tall and 50% dwarf

  4. 75% tall and 25% dwarf
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 In peas, tall plant trait is dominant over dwarf. If a heterozygous for tall is crossed with one homozygous for dwarf, there will be 50% tall and 50% dwarf appearance of the offspring of a cross of F1.

Multiple choice

A child who inherits an X chromosome from the father will be a

  1. boy

  2. girl

  3. Either (1) or (2)

  4. Cannot be determined
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

We know that a mother, being female (XX), can contribute only X chromosome to the progeny. If a child inherits X chromosome from the father, then its genetic makeup will contain a pair of X chromosomes, i.e. XX state, and the child will develop into a girl.

Multiple choice

In which mode of inheritance do you expect more maternal influence among the offspring?

  1. Autosomal

  2. Cytoplasmic

  3. Y-linked

  4. X-linked
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cytoplasmic inheritance shows stronger maternal influence because organelles like mitochondria and chloroplasts (which have their own DNA) are inherited primarily through the egg's cytoplasm. The sperm contributes mainly nuclear DNA with minimal cytoplasm. X-linked inheritance comes from both parents (mother's X and father's X or Y).

Multiple choice

Cross breeding is the crossing of two different pure breeds or populations, as a result of mixing the genetic contributions of its parents the offspring exhibit the characters of both the parents. What is this condition referred to as?

  1. Co-dominace

  2. Dominant epistasis

  3. Heterosis

  4. Duplicate Dominant Interaction
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Heterosis is the improved or increased function of any biological quality in a hybrid offspring. An offspring exhibits heterosis if its traits are enhanced as a result of mixing the genetic contributions of its parents.

Multiple choice

In maize, hybrid vigour is exploited by

  1. bombarding the protoplast with DNA

  2. crossing of two inbreed parental lines

  3. harvesting seeds from the most productive plants

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

In maize, hybrid vigour is exploited by crossing of two inbreed parental lines. 

Multiple choice

Which of the following shows codominance pattern of inheritance?

  1. Flower colour in garden pea

  2. Flower colour in snapdragon

  3. ABO blood group

  4. Both 2 and 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Snapdragon flower color: FRallele is for red flower colour and FWallele for white flower and in when both FRFW condition it will be pink due to codominance and in ABO blood group A and B alleles are codominant to each other.