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 bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

A child has blood group B. Mother has blood group A. The blood group of the father would be

  1. O

  2. O or A

  3. B or AB

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

Child is B (genotype BO or BB). Mother is A (genotype AO or AA). To have a B child, the father must provide a B allele. Thus, the father could be B (BO or BB) or AB.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

The genotype of B-group father of an O-group child is

  1. $I^O I^O$
  2. $I^B I^B$
  3. $I^A I^B$
  4. $I^O I^B$.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A child with blood group O has genotype OO. If the father is blood group B, he must be heterozygous (genotype BO, represented as I^O I^B) to pass on the O allele to the child.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

A man with blood group A marries AB blood group woman. Which type of progeny indicate that the man is not homozygous?

  1. AB

  2. B

  3. A

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

A man with blood group A can have genotype AA or AO. If he is AO and marries an AB woman (genotypes A and B), they can produce a child with blood group B (genotype BO). If he were AA, he could only produce A or AB children.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

Parents with blood groups O and AB cannot have AB child as

  1. Gene for O is dominant over gene for B

  2. Gene for O is dominant over gene for A

  3. Genes for A and B are absent in one of the parents

  4. Gene for A or B is absent in one of the parents.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A parent with blood group O has the genotype OO. A parent with blood group AB has the genotype AB. The child must inherit an O from the first parent, making it impossible for the child to have the genotype AB.

Multiple choice bio-chemistry immunity and blood groups blood group blood groups and compatibility advance blood groups and transfusion compatibility of blood groups

A boy has the blood group 0. What is true of the inheritance of this blood group in his case?

  1. His mother should be with AB blood group

  2. Both his parents could be heterozygous A group

  3. His father could be homozygous B group

  4. His mother could be homozygous A group
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If the boy has blood group o, both his parents could probably be heterozygous A group, $I^AI^O$, in both the parents.

So, the correct option is 'Both his parents could be heterozygous A group'.

Multiple choice bio-chemistry immunology blood group blood groups and compatibility advance blood groups and transfusion

Choose the correct answer from the alternatives given.
Which of the following is an example of codominance?

  1. Pink flowers of snapdragon

  2. The ABO blood groups in humans

  3. Sex-linkage in humans

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Pink flowers of Snapdragon is a heterozygote phenotype and an intermediate phenotype of the two homozygous phenotypes from which it originates. It is an example of incomplete dominance.
  • Codominance is seen when both the alleles are expressed simultaneously and neither of the alleles is dominant over the other. In human ABO blood grouping system both the alleles I$^A$ and I$^B$ are codominant and hence in the AB blood group individuals both the antigens, A and B are seen. So, the human ABO blood grouping is an example of codominance.
  • The expression of the sex chromosomes in humans differ in males and females and hence are said to be sex-linked.
So, the correct option is 'The ABO blood groups in humans'.
Multiple choice photosystems photosynthesis in plants metabolism, cell respiration, and photosynthesis photosynthesis in higher plants biology

When two hybrids Ttrr & Rrtt are crossed, the phenotypic ratio of offspring shall be?

  1. $3:1$
  2. $1:1:1:1$
  3. $1:1$
  4. $9:3:3:1$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • When Ttrr x Rrtt is performed, 4 types of phenotypes are obtained in equal numbers. (1:1:1:1)
  • The gametes for Ttrr are Tr and tr and for Rrtt are Rt and rt.
  • The possible genotypes are TtRr, Ttrr, ttRr, ttrr which are all different phenotypically.
  • So. the correct answer is '1:1:1:1'.
Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

Feulgen test, is unique for DNA, is a

  1. Gentian violet

  2. Neutral red

  3. Basic fuchsin

  4. Cotton blue
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The feulgen test is a staining technique discovered by Robert Feulgen and used in histology to identify chromosomal material or DNA in cell specimens.
  • The Feulgen test, is unique for DNA, is a Basic Fuchsin.
  • It is used for demonstration of DNA (deoxyribonucleic acid) in tissue sections. 
  • So, the correct answer is 'Basic fuchsin',   
Multiple choice structure of dna and rna nucleic acids and polynucleotides nucleic acids and protein synthesis molecular biology biology

Suppose two species A and B share 94% of their DNA with each other and species C shares 75% of DNA sequence with and B. What inference can be drawn from it ?

  1. Species A and B share more recent common ancestor with each other than either shares with C.

  2. Species C evolved more recently than species A and B.

  3. Species C is more closely related to species B than to species A.

  4. Species A and B have common ancestor but neither have common ancestor with species C.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Higher DNA sequence similarity indicates a more recent common ancestor. Since A and B share 94% and C shares less with them, A and B are more closely related.

Multiple choice evs - i busy at work - our internal organs human lymphatic system lymph and its function lymph and tissue fluid

If the father has blood group A and mother has blood group O, which one of following may be the son's blood group?

  1. B

  2. AB

  3. O

  4. B, AB and O
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If the father is blood group A (genotype AA or AO) and the mother is O (genotype OO), the possible offspring genotypes are AO or OO, resulting in blood group A or O.

Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

Match the following.

A. IAA (i) Herring sperm DNA
B. ABA (ii) Bolting
C. Ethylene (iii) Stomatal closure
D. GA (iv) Weed-free lawns
E. Cytokinins (v) Ripening of fruits

  1. A-(iv), B-(iii), C-(v), D-(ii), E-(i)

  2. A-(v), B-(iii), C-(iv), D-(ii), E-(i)

  3. A-(iv), B-(i), C-(iv), D-(iii), E-(ii)

  4. A-(v), B-(iii), C-(ii), D-(i), E-(iv)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

IAA is an auxin but has potential role of herbicide and weedicide. ABA is stress inducing plant growth regular. It can induce closure of stomata, Ethylene on other hand increases climactic rate and hence used for fruit ripening, GA or gibberlic acid are known to cause bolting in crucifers. Cytokinins were first isolated from Herring sperm DNA.

Thus, the correct answer is 'A-(iv), B-(iii), C-(v), D-(ii), E-(i).'