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

A gene which suppresses the effect of a gene at another locus is

  1. epistatic

  2. hypostatic

  3. lethal gene

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

Epistasis is a genetic interaction where one gene masks or interferes with the expression of another gene at a different locus. The gene that does the masking is epistatic, and the one being masked is hypostatic.

Multiple choice

The three important laws of heredity proposed by Mendel relate to

  1. linkage, segregation and independent assortment

  2. dominance, independence assortment and linkage

  3. segregation, independent assortment, and dominance and recessiveness

  4. segregation, linkage and mutation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Mendel's primary contributions to genetics are summarized in three laws: the Law of Dominance, the Law of Segregation, and the Law of Independent Assortment. While linkage and mutations are important genetic concepts, they were discovered and described by later scientists like Morgan and de Vries.

Multiple choice

Crossing over in diploid organisms is responsible for

  1. dominance of genes

  2. linkage between genes

  3. segregation of alleles

  4. recombination of linked genes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Crossing over occurs during meiosis and involves the exchange of genetic material between non-sister chromatids of homologous chromosomes, which leads to new combinations of linked genes.

Multiple choice

The cross between two pairs of alleles is called

  1. crossing over

  2. linkage

  3. monohybrid cross

  4. dihybrid cross
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A cross involving two pairs of alleles (e.g., RrYy x RrYy) is defined as a dihybrid cross, as it tracks two distinct traits simultaneously.

Multiple choice

Triticale is an:

  1. Aneuploid

  2. Interspecific man-made hybrid

  3. Allotetraploid

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

Triticale is a man-made hybrid created by crossing wheat (Triticum) and rye (Secale). It is an allopolyploid (specifically an allotetraploid or allohexaploid depending on the cross).

Multiple choice

Which of the following statements are TRUE? P. Maximum parsimony is not a character-based method in tree construction. Q. A bifurcating branch point in the phylogenetic tree is known as clade. R. Pedigree is a tree representation of a family showing the relationships between members and the pattern of inheritance of a given trait. S. UPGMA is a distance-based method in tree construction.

  1. Only P and Q

  2. Only P and S

  3. Only Q and R

  4. Only Q and S

  5. Only R and S
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Yes, this is the correct answer. Both statements are true. A tree representation of a family showing the relationships between members and the pattern of inheritance of a given trait is known as pedigree. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) is a distance-based method in tree construction.

Multiple choice

Fill blank (ii).

Directions: Read the following passage having some numbered blanks.

In jaguars, the mutation is (i)_______. Hence, black jaguars can (ii)_______ both black and (iii)______ cubs, but spotted jaguars only (iv)_______ spotted cubs when bred together. In leopards, the (v)_______ is recessive and some spotted leopards can produce the black cubs if both (vi)________ carry the gene in hidden form, while black leopards always breed true when mated together. In (vii)______ mounted specimens, black leopards often (viii)_______ to a rusty color, but black jaguars fade to chocolate brown. (ix)_______ black jaguar was (x)________ a separate species by indigenous people.

  1. produce

  2. outgrow

  3. harvest

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

Here, 'produce' is the correct option as it means to create or to generate. Other options are irrelevant in this context. 'Outgrow' is to grow too large or too mature, 'harvest' is the process or period of gathering the crop and to 'attain' is to succeed in achieving something.

Multiple choice

Fill blank (iii).

Directions: Read the following passage having some numbered blanks.

In jaguars, the mutation is (i)_______. Hence, black jaguars can (ii)_______ both black and (iii)______ cubs, but spotted jaguars only (iv)_______ spotted cubs when bred together. In leopards, the (v)_______ is recessive and some spotted leopards can produce the black cubs if both (vi)________ carry the gene in hidden form, while black leopards always breed true when mated together. In (vii)______ mounted specimens, black leopards often (viii)_______ to a rusty color, but black jaguars fade to chocolate brown. (ix)_______ black jaguar was (x)________ a separate species by indigenous people.

  1. spotted

  2. patchy

  3. checkered

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

Here, spotted is the correct option as the young ones of a leopard are spotted. ‘Patchy’ is irregular in appearance, ‘checkered’ is an arrangement of squares of different colour and ‘stained’ is mark or discolour with something that is not easily removed. The young ones are not patchy, checkered or stained.

Multiple choice

Fill blank (iv).

Directions: Read the following passage having some numbered blanks.

In jaguars, the mutation is (i)_______. Hence, black jaguars can (ii)_______ both black and (iii)______ cubs, but spotted jaguars only (iv)_______ spotted cubs when bred together. In leopards, the (v)_______ is recessive and some spotted leopards can produce the black cubs if both (vi)________ carry the gene in hidden form, while black leopards always breed true when mated together. In (vii)______ mounted specimens, black leopards often (viii)_______ to a rusty color, but black jaguars fade to chocolate brown. (ix)_______ black jaguar was (x)________ a separate species by indigenous people.

  1. discharge

  2. attain

  3. harvest

  4. produce
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Here, 'produce' is the correct option as produce here implies to create or form something as part of a physical process. ‘Discharge’ implies allowing a liquid, gas or other substance to flow out from where it has been confined and ‘harvest’ implies the process of gathering the crop.

Multiple choice

Fill blank (vi).

Directions: Read the following passage having some numbered blanks.

In jaguars, the mutation is (i)_______. Hence, black jaguars can (ii)_______ both black and (iii)______ cubs, but spotted jaguars only (iv)_______ spotted cubs when bred together. In leopards, the (v)_______ is recessive and some spotted leopards can produce the black cubs if both (vi)________ carry the gene in hidden form, while black leopards always breed true when mated together. In (vii)______ mounted specimens, black leopards often (viii)_______ to a rusty color, but black jaguars fade to chocolate brown. (ix)_______ black jaguar was (x)________ a separate species by indigenous people.

  1. architects

  2. custodians

  3. parents

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

Here, 'parents' is the correct option as parent is one that begets or brings forth offspring. ‘Architect’ is a person who designs buildings and in many cases, also supervises their construction, ‘custodian’ is a person who has responsibility for taking care of or protecting something and ‘prototype’ is a first or preliminary version of a device or vehicle from which other forms are developed.