Genetics Questions

There are two opposing views about the origin of Modern man. According to one view, Homo erectus in Asia were the ancestors of modern man. A study of variations of DNA, however, suggested African origin of Modern man. What kind of observation on DNA variation could suggest this?

A man and a woman, who do not show any apparent signs of a certain inherited disease, have seven children (2 daughters and 5 sons). Three of the sons suffer from the given disease but none of the daughters are affected. Which of the following mode of inheritance do you suggest for this disease?

Genes for cytoplasmic male sterility in plants are generally located in:

Which one of the following is not true for a species?

At a particular locus, frequency of 'A' allele is 0.6 and that of 'a' is 0.4. What would be the frequency of heterozygotes in a random mating population at equilibrium?

Which one of the following conditions correctly describes the manner of determining the sex in the given example?

What would be the number of chromosomes of the aleurone cells of a plant with $42$ chromosomes in its root tip cells?

Mutations can be induced with:

Which of the following statements about molecular taxonomy is correct?

Which of the following is correct about molecular taxonomy?

Which of the following is incorrect about molecular taxonomy?

A man whose father was colour blind marries a woman who had a colour blind mother and a normal father. What percentage of male children of this couple will be colour blind?

The incorrect statement with regard to Haemophilia is:

In a population of $1000$ individuals, $360$ belong to genotype $AA$, $480$ to $Aa$ and the remaining $160$ to $aa$. Based on this data, the frequency of allele $A$ in the population is:

A human female with Turner's syndrome:

A colour blind man marries a woman with normal sight who has no history of colour blindness in her family. What is the probability of their grandson being colour blind?

The term ‘’linkage’’ was coined by:

A pleiotropic gene:

Fruit colour in squash is an example of:

Transformation was discovered by:

In a dihybrid cross ($AaBb\times AaBb$), the phenotypic ratio of the offspring is:

If both parents are carriers for Thalassemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected child?

Which one of the following is not applicable to RNA?

If two persons with 'AB' blood group marry and have children, the children could be classified as 'A' : 'AB' : 'B' in a $1:2:1$ ratio. Protein electrophoresis reveals presence of both 'A' and 'B' type proteins in 'AB' individuals. This is an example of:

Which of the following statements is not true of two genes that show $50\%$ recombination frequency?

$F_2$ generation in a Mendelian cross showed that both genotypic and phenotypic ratios are same as $1:2:1$. It represents a case of:

A normal-visioned man whose father was colour-blind, marries a woman whose father was also colour-blind. They have their first child as a daughter. What are the chances that this child would be colour-blind?

A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the $F_1$ plants were selfed the resulting genotypes were in the ratio of:

In Hardy-Weinberg equation, the frequency of heterozygous individual is represented by:

Genetic drift operates in:

If a colour-blind man marries a woman who is homozygous for normal colour vision, the probability of their son being colour-blind is:

A true breeding plant is:

The mechanism that causes a gene to move from one linkage group to another is called:

Match Column-I with Column-II:Column-I: (a) Pistils fused together, (b) Formation of gametes, (c) Hyphae of higher Ascomycetes, (d) Unisexual female flowerColumn-II: (i) Gametogenesis, (ii) Pistillate, (iii) Syncarpous, (iv) Dikaryotic

Which one of the following generates new genetic combinations leading to variation?

Pick out the correct statements:(i) Haemophilia is a sex – linked recessive disease(ii) Down’s syndrome is due to aneuploidy(iii) Phenylketonuria is an autosomal recessive gene disorder(iv) Sickle cell anaemia is an autosomal recessive gene disorder

A complex of ribosomes attached to single strand of RNA is known as:

Which of the following is required as inducer(s) for the expression of Lac operon?

In his classic experiments on pea plants, Mendel did not use:

Which one of the following is the starter codon?

Which of the following most appropriately describes haemophilia?

Match the terms in column I with their description in Column II:
Column I: (a) Dominance, (b) Codominance, (c) Pleiotropy, (d) Polygenic inheritance
Column II: (i) Many genes govern a single character, (ii) In a heterozygous organism only one allele expresses itself, (iii) In a heterozygous organism both alleles express themselves fully, (iv) A single gene influences many characters

In a testcross involving $F_1$ dihybrid flies, more parental – type offspring were produced than the recombinant – type offspring. This indicates:

Satellite DNA is important because it:

Balbiani rings are sites of:

In the following human pedigree, the filled symbols represent the affected individuals. Identify the type of given pedigree.

Test cross in plants or in $\text{Drosophila}$ involves crossing:

Identify the correct order of organisation of genetic material from largest to smallest:

A gene showing codominance has:

Comparative biochemistry provides a strong evidence in favour of common ancestry of living beings.

The two polynucleotide chains in DNA are:

The Okazaki fragments in DNA chain growth:

During transcription, RNA polymerase holoenzyme binds to a gene promoter and assumes a saddle-like structure. What is its DNA-binding sequence?

In maize, hybrid vigour is exploited by:

Molecular basis of organ differentiation depends on the modulation in transcription by:

In the hexaploid wheat, the haploid ($n$) and basic ($x$) numbers of chromosomes are:

A human male produces sperms with the genotypes AB, Ab, aB and ab pertaining to two diallelic characters in equal proportions. What is the corresponding genotype of this person?

Telomere repetitive DNA sequences control the function of eukaryotic chromosomes because they:

What would be the number of chromosomes in the cells of the aleurone layer in a plant species with 8 chromosomes in its synergids ?

Inheritance of skin colour in humans is an example of:

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.

Assertion : Senescence is the time when age associated defects are manifested.Reason : Certain genes may be undergoing sequential switching on and off during one's life.

Primary source of allelic variation is:

Grain colour in wheat is determined by three pairs of polygenes. Following the cross AABBCC (dark colour) x aabbcc (light colour), in $F_2$ generation what proportion of the progeny is likely to resemble either parent?

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

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

The trait traced in the above pedigree chart is:

Which one of the following statements is true for protein synthesis (translation)?

Genes for cytoplasmic male sterility in plants are generally located in :

Which condition is correctly matched with its chromosomal abnormality?

A test cross is carried out to:

In history of biology, human genome project led to the development of:

A man and a woman, who do not show any apparent signs of a certain inherited disease, have seven children (2 daughters and 5 sons). Three of the sons suffer from the given disease but none of the daughters are affected. Which of the following mode of inheritance do you suggest for this disease ?

Which one of the following conditions of the zygotic cell would lead to the birth of a normal human female child?

The unequivocal proof of $\text{DNA}$ as the genetic material came from the studies on a:

Which one of the following symbols and its representation used in human pedigree analysis is correct?

Point mutation involves:

The most popularly known blood grouping is the $\text{ABO}$ grouping. It is named $\text{ABO}$ and not $\text{ABC}$, because "O" refers to having:

Study the pedigree chart given below:What does it show?

Read the following four statements (A - D):(A) In transcription, adenosine pairs with uracil.(B) Regulation of lac operon by repressor is referred to as positive regulation.(C) The human genome has approximately $50,000$ genes.(D) Haemophilia is a sex-linked recessive disease.How many of the above statements are right?

Haploids are more suitable for mutation studies than diploids because:

How does molecular taxonomy help in classification?

Which of the following provides the most reliable classification of organisms?

In pea plants, yellow seeds are dominant to green. If a heterozygous yellow seeded plant is crossed with a green seeded plant, what ratio of yellow and green seeded plants would you expect in $F_1$ generation?

A common test to find the genotype of a hybrid is by:

Select the correct statement from the following:

Two genes R and Y are located very close on the chromosomal linkage map of maize plant. When RRYY and rryy genotypes are hybridized, then $F_2$ segregation will show:

One gene-one enzyme relationship was established for the first time in: