Biology

Genetics and Evolutionary Biology

1,123 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

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).

Multiple choice

Among which of the following types of speciation, genetic drift is supposed to play a significant role?

  1. Allopatric speciation

  2. Peripatric speciation

  3. Parapatric speciation

  4. Sympatric speciation

  5. Natural speciation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In peripatric speciation, new species are formed in isolated, smaller peripheral populations that are prevented from exchanging genes with the main population. Genetic drift is often proposed to play a significant role in peripatric speciation.

Multiple choice

We are all unique. Every one of us has a unique combination of traits. Which among the following variable traits are influenced by a combination of genes and environmental factors?

  1. Earlobe attachment

  2. Tongue rolling

  3. Dimples

  4. Handedness

  5. Freckles
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Some people can curl up the sides of their tongue to form a tube shape. Tongue rolling is controlled by a single gene. However, people can learn to roll their tongue as they get older, suggesting that environmental factors also influences the trait.

Multiple choice

Which of the following is not true about hybridisation?

  1. Hybridisation refers to the crossing between genetically dissimilar plants.

  2. Crossing between two different species of the same genus is called inter specific.

  3. Crop production can be decreased by biotic and abiotic stresses under different situations.

  4. None of these

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hybridisation refers to the crossing between genetically dissimilar plants. Crop production can be decreased by biotic and abiotic stresses under different situations.

Multiple choice

Continuous inbreeding is not recommended for a small population because

  1. it makes the genetic diversity comparatively small

  2. it makes the genetic diversity comparatively larger and richer

  3. it enhances the rate of mutations

  4. it decreases the rate of mutations
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Usually closely related individuals are genetically similiar. When they mate, there is a less chance of occurrence of significantly new genetic combinations. Compared to crossbreeding, there will be reduced genetic diversity and increased homozygosity.