Biology

Genetics and Evolutionary Biology

1,156 Questions

Genetics and evolutionary biology explain how traits are passed from parents to offspring and how species change over time. Key concepts include genetic drift, inbreeding, and heredity. This topic is fundamental for the biology section of many competitive tests.

Heredity and traitsGenetic variations and driftInbreeding conceptsEvolutionary mechanisms

Genetics and Evolutionary Biology Questions

Multiple choice

Sum total of genes in a population is

  1. genotype

  2. gene flow

  3. genetic constitution

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

The gene pool is defined as the sum total of all genes and their alleles present in a population at any given time.

Multiple choice

'Philosophie Zoologique' was written by

  1. De Vries

  2. Lamarck

  3. Mendel

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

'Philosophie Zoologique' was published in 1809 by Jean-Baptiste Lamarck, outlining his theory of evolution.

Multiple choice

Genetic drift

  1. is random change in gene frequency

  2. has nothing in common with inbreeding

  3. is an orderly change in gene frequency

  4. produces greatest fluctuations in large populations
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Genetic drift is the change in the frequency of an existing gene variant (allele) in a population due to random sampling of organisms. It is most pronounced in small populations.

Multiple choice

Frequency of a gene in a population will increase if the gene is

  1. lethal

  2. dominant

  3. recessive

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

According to the principles of natural selection, alleles that provide a fitness advantage to the organism in a given environment are more likely to be passed on to the next generation, thus increasing their frequency in the population.

Multiple choice

Which of the following is not true for a species?

  1. Members of a species can interbreed.

  2. Gene flow does not occur between the populations of a species.

  3. Each species is reproductively isolated from every other species.

  4. Variations occur among members of a species.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

By definition, a species is a group of interbreeding populations that are reproductively isolated from other such groups. Gene flow is a defining characteristic that maintains the cohesion of a species, so stating it does not occur is incorrect.

Multiple choice

The chances of elimination of genes from a small population is an example of

  1. selection pressure

  2. speciation

  3. adaptation

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

Genetic drift or Sewall Wright effect is an important mechanism in evolutionary change in small populations. In a small population not all the alleles which are representative of that species may be present. Therefore, chance events may result in the elimination of that allele form population. 

Multiple choice

Mutation can be introduced by

  1. mustard gas

  2. UV rays

  3. hexagonal RX

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

Mustard gas caused genetic damage in all systems in which it was tested. It caused DNA damage.

Multiple choice

Directions: Read the paragraph and answer the question that follows.

Very early in the study of genetics biologists began to pay particular attention to the aberrations now known as mutations; this investigation was initiated by de Vries at the turn of the century and brilliantly developed by Morgan and his school from 1910 on. A gene, by definition, is a living particle that reproduces itself, and nearly always it does so exactly. But occasionally, probably under the influence of some outside agent, it forms an imperfect copy of itself. If this altered gene is able to reproduce itself in its new form, the result is a mutation, which is evidenced in permanent change in some trait of the organism.

What according to you would succeed the passage?

  1. Mutation is the antithesis of heredity.

  2. Mutation is detrimental to the reproduction of gene.

  3. Mutation occurs when genes do not reproduce themselves.

  4. Mutation brings about a noxious change in the trait of an organism.

  5. This mutative trait becomes the hallmark of the species.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Heredity ensures the basic continuity of the organic form, whereas mutation creates a diversity of genes, under the influence of some external agent. Thus, mutation is the antithesis of heredity. Hence, (1) is the answer. 

Multiple choice

Which of the following statements can be excluded from the characteristics of microsatellites?

  1. Microsatellites can be amplified for identification by the polymerase chain reaction process.

  2. Random microsatellite primers can be developed by cloning random segments of DNA from the focal species.

  3. Almost 50% of the human genome is contained in various types of transposable elements.

  4. Microsatellites within introns also influence genotype.

  5. Length changes of microsatellites within promoters and other cis-regulatory regions can also change gene expression among the generations.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Microsatellites within introns also influence phenotype. For example, a GAA triplet expansion in the first intron of the X25 gene appears to interfere with transcription, and causes Friedreich Ataxia (Bidichandani 1998).