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

How many alleles can an organism have for a given gene?

  1. One

  2. Two

  3. Three

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

An organism typically has two alleles for a given gene, one inherited from each parent.

Multiple choice

What is a homozygous genotype?

  1. A genotype with two identical alleles

  2. A genotype with two different alleles

  3. A genotype with three alleles

  4. A genotype with four alleles
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A homozygous genotype is a genotype in which both alleles for a given gene are identical.

Multiple choice

What is a heterozygous genotype?

  1. A genotype with two identical alleles

  2. A genotype with two different alleles

  3. A genotype with three alleles

  4. A genotype with four alleles
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A heterozygous genotype is a genotype in which the two alleles for a given gene are different.

Multiple choice

What is a dominant allele?

  1. An allele that is always expressed in the phenotype

  2. An allele that is never expressed in the phenotype

  3. An allele that is expressed only in homozygous genotypes

  4. An allele that is expressed only in heterozygous genotypes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A dominant allele is an allele that is always expressed in the phenotype, regardless of the presence of other alleles.

Multiple choice

What is a recessive allele?

  1. An allele that is always expressed in the phenotype

  2. An allele that is never expressed in the phenotype

  3. An allele that is expressed only in homozygous genotypes

  4. An allele that is expressed only in heterozygous genotypes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A recessive allele is an allele that is expressed in the phenotype only when an organism has two copies of that allele.

Multiple choice

What is a monohybrid cross?

  1. A cross between two organisms that differ in one gene

  2. A cross between two organisms that differ in two genes

  3. A cross between two organisms that differ in three genes

  4. A cross between two organisms that differ in four genes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A monohybrid cross is a genetic cross between two organisms that differ in one gene.

Multiple choice

What is a dihybrid cross?

  1. A cross between two organisms that differ in one gene

  2. A cross between two organisms that differ in two genes

  3. A cross between two organisms that differ in three genes

  4. A cross between two organisms that differ in four genes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A dihybrid cross is a genetic cross between two organisms that differ in two genes.

Multiple choice

What is a testcross?

  1. A cross between a homozygous dominant organism and a heterozygous organism

  2. A cross between a homozygous recessive organism and a heterozygous organism

  3. A cross between two homozygous dominant organisms

  4. A cross between two homozygous recessive organisms
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A testcross is a genetic cross between a homozygous dominant organism and a heterozygous organism to determine the genotype of the heterozygous organism.

Multiple choice

What is a backcross?

  1. A cross between a heterozygous organism and a homozygous dominant organism

  2. A cross between a heterozygous organism and a homozygous recessive organism

  3. A cross between two heterozygous organisms

  4. A cross between two homozygous organisms
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A backcross is a genetic cross between a heterozygous organism and a homozygous recessive organism to determine the genotype of the heterozygous organism.

Multiple choice

What is a pedigree chart?

  1. A diagram that shows the family history of a genetic trait

  2. A diagram that shows the genotype of a family

  3. A diagram that shows the phenotype of a family

  4. A diagram that shows the sex of a family
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A pedigree chart is a diagram that shows the family history of a genetic trait, including the relationships between family members and the inheritance of the trait.

Multiple choice

What is the term for the genetic makeup of an individual?

  1. Genome

  2. Genotype

  3. Phenotype

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

The genotype of an individual is the genetic makeup of that individual, consisting of the alleles at all of their genes.

Multiple choice

In incomplete dominance, the heterozygous genotype results in:

  1. A blend of the two phenotypes

  2. An intermediate phenotype

  3. A dominant phenotype

  4. A recessive phenotype
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Incomplete dominance occurs when neither allele is dominant over the other, resulting in a heterozygous individual expressing a phenotype that is a blend of the two homozygous phenotypes.

Multiple choice

What is the genotypic ratio of a cross between two heterozygous individuals in incomplete dominance?

  1. 1:2:1

  2. 3:1

  3. 1:1

  4. 9:3:3:1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In a cross between two heterozygous individuals, the genotypic ratio is 1:2:1, where 1 represents homozygous dominant, 2 represents heterozygous, and 1 represents homozygous recessive.

Multiple choice

Incomplete dominance is also known as:

  1. Partial dominance

  2. Codominance

  3. Blended inheritance

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Incomplete dominance is also referred to as partial dominance, codominance, and blended inheritance, as it involves a blend of the phenotypes of the two homozygous genotypes.

Multiple choice

In incomplete dominance, the heterozygous phenotype is:

  1. Identical to the dominant phenotype

  2. Identical to the recessive phenotype

  3. A blend of the two phenotypes

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In incomplete dominance, the heterozygous phenotype is a blend of the two phenotypes expressed by the homozygous dominant and recessive genotypes.