AIIMS Botany Principles Of Inheritance And Variation Class 12 Questions

Genes on same chromosome can be

Which of the following is a sex linked character

Assertion: Down syndrome, Klinfelter syndrome and Turner syndrome are chromosomal disorders. Reason: In Klinfelter syndrome females are sterile.

Match the Column-I with II

When heterozygous tall (Tt) is crossed with a recessive parent (tt), then 50% of the offspring will be homozygous recessive.

A colour blind man marry with a daughter of colour blind father, the generation will be

In a plant, red fruit (R) dominant over yellow fruit (r) and tallness (T) is dominant over shortness (t). If a plant with RRTT genotype is crossed with a plant that is rrtt. Then

Assertion : Inbreeding increases homozygosity, thus exposes harmful recessive genes, which are eliminated by selection. Reason : Continued inbreeding reduces fertility and productivity.

Assertion : HbS HbS denotes the homozygous condition for sickle-cell anaemia. Reason : It occurs due to substitution of glutamic acid by valine at the 6^{th} position of β-chain of Hb.

Assertion : A middle aged woman is reported to have small breasts and undersized uterus. Reason : Her genotypic analysis shows XO condition of allosomes.

Which of the following is correct?

Assertion : A geneticist crossed two plants, he got 50% tall and 50% dwarf progenies. Reason : It follows Mendelian law as one of the parent plant might be heterozygous.

Which of the following disorders are caused due to recessive autosomal mutations?

Which of the following diseases is also called Christmas disease?

Assertion: Inbreeding produces pureline. Reason: It causes homozygosity.

Assertion: Antirrhinum is a good example to understand incomplete dominance. Reason: Heterozygotes show characteristics of both the alleles.

Which of the following species has the chromosome complement similar to that of Triticum aestivum?

Eugenics is the branch concerned with

Percentage of recombination between A and B is 9%, A and C is 17%, B and C is 26%, then the arrangement of genes is

Which of the following conditions represents a case of co-dominant genes?

Assertion: A gamete may carry either of the traits but not both. Reason: This is Mendel’s second law or law of independent assortment.

XO⁻chromosomal abnormality in human beings causes

If a homozygous red-flowered plant is crossed with a homozygous white-flowered plant, the offspring will be

Gene which suppresses other gene's activity but does not lie on the same locus is called as

Pure line breed refers to

Assertion (A) : Haemophilia is a recessive sex linked disease. Reason (R) : Haemophilia occurs due to mutation of a structural gene on chromosome 15.

Which one of the following pairs of features is a good example of polygenic inheritance?

Given below is a highly simplified representation of the human sex chromosomes from a karyotype. The gene a and b could be of

In which one of the following combinations (a-d) of the number of chromosomes is the present day hexaploid wheat correctly represented?

Given below is a pedigree chart showing the inheritance of a certain sex-linked trait in humans.

The 'cri-du-chat' syndrome is caused by change in chromosome structure involving

Grain colour in wheat is determined by three pairs of polygenes. Following the cross AABBCC (dark colour) × aabbcc (light colour), in F₂ generation what proportion of the progeny is likely to resemble either parent?

Primary source of allelic variation is

Assertion : In humans, the gamete contributed by the male determines whether the child produced will be male or female. Reason : Sex in humans is a polygenic trait depending upon a cumulative effect of some genes on X⁻chromosome and some on Y⁻chromosome.

Given below is a pedigree chart of a family with five children. It shows the inheritance of attached ear-lobes as opposed to the free ones. The squares represent the male individuals and circles the female individuals. Which one of the following conclusions drawn is correct?

How many different types of gametes can be formed by F₁ progeny, resulting from the following cross: AA BB CC × aa bb cc

Assertion : The honey bee queen copulates only once in her life time. Reason : The honey bee queen can lay fertilized as well as unfertilized eggs.

One of the genes present exclusively on the X⁻chromosome in humans is concerned with:

Pure line breed refers to

If a homozygous red flowered plant is crossed with a homozygous white flowered plant, the off-spring would be

Barr Body is found in the cytoplasm during:-

The ratio in a dihybrid test cross between two individuals is given by:

“Gametes are never hybrid”. This is a statement of

Mendel was not able to say anything about recombination and crossing over because

A man has enlarged breasts, sparse hair on body and sex compliment as XXY. He then suffers from

Albinism and phenylketonuria are disorders due to

A man has a wound. Normally a bleeding wound develops a clot and flow of blood stops. If this does not happen to the man, then he probably suffers from