The F2 genotypic ratio of a monohybrid cross is:

  • 1 : 1
  • 3 : 1
  • 1 : 2 : 1
  • 3. 9 : 7

In a test cross, the plant expressing the dominant phenotype is crossed with the plant:

  • Which is heterozygous dominant
  • Which is heterozygous recessive
  • Which is homozygous recessive
  • Which is homozygous dominant

Which of the following is not true for the Law of Dominance given by Mendel?

  • Characters are controlled by discrete units called factors.
  • Factors occur in pairs.
  • In a dissimilar pair of factors one member of the pair dominates the other.
  • The alleles show blending at the time of fertilization

What is the F2 genotypic ratio in cases of incomplete dominance?

  • 1 : 1
  • 3 : 1
  • 1 : 2 : 1
  • 1 : 1

Blood group antigens are:

  • Carbohydrates present in plasma
  • Carbohydrates present on the surface of RBCs
  • Plasma proteins
  • Proteins present on the surface of RBCs

 

What can be the blood groups of progeny whose father and mother are of AB and O blood group respectively?

 
  • A and B only
  • AB only
  • All except O
  • A, B, AB and O

“Chromosomes, which are seen in all dividing cells and pass from one generation to the next, are the basis for all genetic inheritance”.
This statement is credited to:

  • Watson and Crick
  • Hershey and Chase
  • Sutton and Boveri
  • Meselson and Stahl

T. H. Morgan worked on the fruit fly, Drosophila melanogaster . Which of the following is not an advantage of this fly?

  • They could be grown on simple synthetic medium in the laboratory.
  • They complete their life cycle in about two years, and a single mating could produce a large number of progeny flies.
  • There was a clear differentiation of the sexes – the male and female flies are easily distinguishable.
  • It has many types of hereditary variations that can be seen with low power microscopes.

When the two genes in a dihybrid cross are situated on the same chromosome:

  • The proportion of parental gene combinations was much higher than the non-parental type.
  • The proportion of parental gene combinations was much lesser than the non-parental type.
  • The proportion of parental gene combinations was equal to the non-parental type.
  • Only recombinants are formed.

During his observation of spermatogenesis in few insects, Henking found that a nuclear structure was received by 50 % of the sperms. He called this structure as:

  • X – body
  • Y – body
  • X – chromosome
  • Y – chromosome

In birds, the mechanism of sex determination is:

  • XX – XY; male heterogamety
  • XX – XY; female heterogamety
  • XX – XO; male heterogamety
  • ZZ – ZW; male heterogamety

It is unfortunate that in our society women are blamed for producing female children and have been ostracised and ill-treated because:

  • The sex is determined by the type of sperm fertilizing the egg
  • The sex is determined by the type of egg fertilizing the sperm
  • The sex is determined by the hormones produced by the fetus
  • The sex is determined by the God’s will

The family pedigree of Queen Victoria shows a number of haemophilic descendants as she was:

  • Affected by the disease
  • Carrier for the disease
  • Did not carry the allele for hemopihilia
  • Was not a queen

Which of the following amino acid substitution in the beta chain of the haemoglobin molecule leads to the development of sickle cell anaemia?

  • Arginine by tyrosine                 
  • Tyrosine by phenylalanine
  • Valine by Glutamic acid             
  • Glutamic acid by Valine

An individual affected with Turner’s Syndrome:
I. Is a female
II. Has 45 chromosomes
III. Has rudimentary ovaries
Of the above statements, the correct statements are:

  • Only I and II                       
  • Only I and III
  • Only II and III                   
  • I, II and III

An organism with two different alleles is:

  • Homozygous for that trait

  • Homologous for the allele
  • Heterozygous for the trait
  • Heterologious for the allele

Which one of the following trait is only expressed in the presence of identical allele?

  •   Yellow seed

  •   Inflated pod

  •   Green pod

  •   Green seed

If a colourblind woman marries a man who has normal colour vision, which of the following is possible w.r.t. their children?

  •   All sons and daughters are colourblind.

  •   All sons and daughters are normal.

  •   100% sons are colourblind.

  •   25% daughters are colourblind.

Continuous source of variations in sexually reproducing organisms is

  •   Disjunction of chromosomes.

  •   Crossing over between sister chromatids.

  •   Crossing over between non-sister chromatids.

  •   Mutation.

The number of linkage groups in pea is

  •   14

  •   7

  •   9

  •   24

How many type(s) of gametes is/are produced by a double recessive parent?

  •   One

  •   Two

  •   Four

  •   Six

Find incorrect match

  • Polygenic inheritance – Spread across of gradient.

  • Pleiotropy – Single gene multiple phenotype.

  • X body of henking – One each in sperm.

  • Pedigree analysis – Mendelian trait.

How many of the following statements are correct?
(1) Phenyl ketonuria leads to mental retardness.
(2) Thalassemia is quantitative where as sickle-cell anaemia is qualitative.
(4) 8% of male & 0.4% of females are haemophilic.

Options

2. 3

  • All 

  • 3. 2 

  • (3) Possibility of female becoming haemophilic is extramely rare.

  • 1

Which of the following traits in the garden pea plant would express itself only in homozygous condition?

  •   Violet flower color

  •   Terminal flower position

  •   Green pod color

  •   Yellow seed color

F1 progeny resemble both the parents in the case of:

  •   Complete dominance

  •   Incomplete dominance

  •   Codominance

  •   Multiple allelism

All the following are examples of Mendelian disorders except:

  •   Hemophilia

  •   Sickle cell anemia

  •   Phenylketonuria

  •   Down's syndrome

The pure line round seeded pea plant was crossed with wrinkled seeded pea plant. The F1 generation is ____ and it can be explained by _____. (respectively)

  • Wrinkled : Law of segregation

  • Round : law of dominance

  • Round : Condominance

  • Wrinkled : Law of dominance

A man suffering from haemophilia marries a normal woman without any history of haemophilia in her family. What percentage of their sons are affected?

  • 100%

  • 75%

  • 50% 

  • 0%

Study the given pedigree chart and choose the correct statement

  •  The trait under study is dominant.

  • Both parents are homozygous.

  • The trait can be X-linked recessive disease haemophilia.

  • The trait depicted is autosomal recessive like cystic fibrosis.

The genotypes of a husband and Wife are IAIB and IAi. 
Among the blood types of their children, how many different genotypes and phenotypes are possible?

  • 3 genotypes; 4 phenotypes

  •  4 genotypes; 3 phenotypes

  •  4 genotypes; 4 phenotypes

  •  3 genotypes; 3 phenotypes

0:0:1


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Practice Botany Quiz Questions and Answers