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 a Mendelian cross, the offspring that exhibit the dominant trait are known as:

  1. Homozygous Dominant

  2. Heterozygous Dominant

  3. Homozygous Recessive

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

Heterozygous dominant individuals carry both the dominant and recessive alleles, expressing the dominant trait while still carrying the recessive allele.

Multiple choice

Which of the following is an example of a dominant trait in humans?

  1. Brown Eyes

  2. Blue Eyes

  3. Attached Earlobes

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

Brown eyes are a dominant trait, meaning that the presence of even one dominant allele for brown eyes will result in the expression of brown eyes.

Multiple choice

In a monohybrid cross, the ratio of dominant to recessive offspring is typically:

  1. 3:1

  2. 1:1

  3. 2:1

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

In a monohybrid cross, where one gene with two alleles is being considered, the expected ratio of dominant to recessive offspring is 3:1.

Multiple choice

The term 'allele' refers to:

  1. Different forms of a gene

  2. Different genes located on the same chromosome

  3. Different genes located on different chromosomes

  4. Different chromosomes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Alleles are different forms of a gene that occupy the same locus on homologous chromosomes.

Multiple choice

In a dihybrid cross, the expected phenotypic ratio is typically:

  1. 9:3:3:1

  2. 3:1

  3. 1:2:1

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

In a dihybrid cross, where two genes with two alleles each are being considered, the expected phenotypic ratio is 9:3:3:1.

Multiple choice

In a testcross, one parent is:

  1. Homozygous Dominant

  2. Heterozygous Dominant

  3. Homozygous Recessive

  4. Heterozygous Recessive
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a testcross, one parent is homozygous recessive, while the other parent is heterozygous dominant or unknown.

Multiple choice

The law of independent assortment states that:

  1. Alleles of different genes assort independently of each other during gamete formation.

  2. Alleles of the same gene assort independently of each other during gamete formation.

  3. Alleles of different genes assort independently of each other during fertilization.

  4. Alleles of the same gene assort independently of each other during fertilization.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The law of independent assortment states that alleles of different genes assort independently of each other during gamete formation, meaning that the inheritance of one gene does not influence the inheritance of another gene.

Multiple choice

Which of the following is an example of a polygenic trait?

  1. Eye Color

  2. Height

  3. Skin Color

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

Eye Color, Height, and Skin Color are all examples of polygenic traits, which are influenced by the interaction of multiple genes.

Multiple choice

The law of dominance states that:

  1. The dominant allele is always expressed in the phenotype.

  2. The recessive allele is always expressed in the phenotype.

  3. Both alleles are expressed in the phenotype.

  4. Neither allele is expressed in the phenotype.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The law of dominance states that the dominant allele is always expressed in the phenotype, while the recessive allele is only expressed in the phenotype when homozygous.

Multiple choice

What is the rule of primogeniture?

  1. The rule that the eldest son inherits all of his father's property.

  2. The rule that the youngest son inherits all of his father's property.

  3. The rule that all of the sons inherit their father's property equally.

  4. The rule that all of the children inherit their father's property equally.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The rule of primogeniture is the rule that the eldest son inherits all of his father's property. This rule was once common in many parts of the world, but it has been abolished in most countries, including India.

Multiple choice

Which research method involves comparing the behavioral traits of monozygotic (identical) and dizygotic (fraternal) twins?

  1. Genome-wide association studies (GWAS)

  2. Pedigree analysis

  3. Twin studies

  4. Candidate gene studies
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Twin studies, particularly those comparing monozygotic and dizygotic twins, are a valuable method for investigating the genetic and environmental influences on behavior.

Multiple choice

What is the heritability of animal personality?

  1. 0-20%

  2. 20-40%

  3. 40-60%

  4. 60-80%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The heritability of animal personality is typically between 20% and 40%. This means that 20-40% of the variation in animal personality is due to genetic factors.

Multiple choice

What is the estimated heritability of alcohol dependence?

  1. 20-30%

  2. 40-50%

  3. 60-70%

  4. 80-90%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Twin and family studies have estimated the heritability of alcohol dependence to be around 40-50%, indicating a significant genetic contribution to the disorder.

Multiple choice

What are the different types of genetic tests?

  1. Single-gene tests.

  2. Multi-gene tests.

  3. Genome-wide sequencing.

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

There are three main types of genetic tests: single-gene tests, multi-gene tests, and genome-wide sequencing. Single-gene tests look for mutations in a single gene that is known to be associated with a particular disease. Multi-gene tests look for mutations in multiple genes that are associated with a particular disease or group of diseases. Genome-wide sequencing looks at all of the genes in a person's genome.

Multiple choice

In Mendelian genetics, the expression of a dominant allele masks the expression of its recessive counterpart. What is this phenomenon called?

  1. Dominance

  2. Recession

  3. Co-dominance

  4. Incomplete Dominance
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Dominance is the phenomenon where one allele in a gene pair masks the expression of the other allele.