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

Which of the following is associated with robust populations that can survive bouts of intense selection?

  1. Proteome

  2. Proteomics

  3. Functional genomics

  4. Genome

  5. Gene pool
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Gene pool is associated with robust populations that can survive bouts of intense selection. Meanwhile, low genetic diversity (see inbreeding and population bottlenecks) can cause reduced biological fitness and an increased chance of extinction, although as explained by genetic drift, new genetic variants, which may cause an increase in the fitness of organisms, are more likely to fix in the population if it is rather small.

Multiple choice

Consider the following statements:

  1. Selective breeding is the process of insertion of genes in plants and animals for desirable traits.
  2. DNA fingerprinting was started in USA.

Which of the given statements is/are incorrect?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Statement (1) is correct. Selective breeding (also called artificial selection and unnatural selection) is the process of is the process of insertion of genes in plants and animals for desirable traits. Statement 2 is incorrect. DNA fingerprinting was started by Alec Jeffrey in UK.

Multiple choice

Consider the following statements: (1) The chemicals, which can cause the genetic variation are called mutagens. (2) Ionising radiations (X-rays, gamma rays, cosmic rays, etc.) can cause genetic variation.

Which of the given statements is/are correct?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statement (1) is correct. Mutagens are the chemicals, which can cause the genetic variation. For example, nitrous acid, alkylating agents,etc. Statement (2) is also correct. The ionising radiations (X-rays, gamma rays, cosmic rays, etc.) can cause the genetic variation.

Multiple choice

Consider the following statements:

  1. Heredity is not responsible for the development of new species.
  2. The human traits are influenced by DNA of both mother and father.

Which of the given statements is/are correct?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statement (1) is correct. Heredity is not responsible for the development of new species. Statement (2) is also correct. The human traits are influenced from the DNA of both mother and father.

Multiple choice

Which of the following is responsible for allopatric speciation?

  1. It occurs when genetically related populations inhabit a widely separated geographical area.

  2. It occurs when genetically unrelated populations inhabit a widely separated geographical area.

  3. It occurs when genetically related populations inhabit the same geographical area.

  4. It occurs when genetically mixed populations inhabit the geographical area.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During the course of allopatric speciation, a part of the population become geographically isolated from the main population.

Multiple choice

Match the following and choose the correct option given below ||| |---|---| |A. Cline|i. It is an assemblage of closely related interbreeding individuals of a species.| |B. Biotype|ii. Transient population between species having the same genotypes and species having different genotypes.| |C. Ecotype|iii. Group of individuals of a species having the same genotype.| |D. Deme|iv. Genetically different populations of a species colonizing different specific habitat.|

  1. A – iv, B – iii, C – ii, D – i

  2. A – ii, B – iii, C – iv, D – i

  3. A – iii, B – ii, C – iv, D – i

  4. A – iii, B – iv, C – i, D – ii
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cline – Transient population between species having same genotypes and species having different genotypes.  Biotype - Group of individuals of a species having same type of genotype.  Ecotype - Genetically different populations of a species colonizing different specific habitat. Deme - It is an assemblage of closely related interbreeding individuals of a species.

Multiple choice

Within a population and due to competition between individuals, the individuals with an advantage will survive to pass their genes on to the next generation. What is this idea called?

  1. Adaptation

  2. Darwin's theory

  3. Speciation

  4. Natural selection
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Natural selection is the process where individuals with advantageous traits survive and reproduce more successfully than others in a competitive environment. These beneficial traits are then passed to offspring, becoming more common in the population over generations. Adaptation is the outcome of this process, not the process itself. Darwin's theory is broader, encompassing natural selection as the key mechanism.

Multiple choice

What is the difference between genetic drift and change due to natural selection?

  1. Genetic drift does not require the presence of variation.

  2. Genetic drift does not involve the competition between members of a species.

  3. Genetic drift never occurs in nature, natural selection does.

  4. There is no difference between these two.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The key difference is that genetic drift is random change in allele frequencies unrelated to fitness advantages, while natural selection involves differential survival based on competitive advantages. Genetic drift occurs through chance events (bottlenecks, founder effects) without requiring competition between organisms. Natural selection specifically requires competition where advantageous traits are favored.

Multiple choice

All of the following are believed to contribute to genomic diversity among various species except

  1. gene duplication

  2. gene transcription

  3. lateral gene transfer

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

Gene transcription is the process of making RNA from DNA - a routine cellular function that happens constantly and does not create genetic diversity. Gene duplication creates extra copies that can evolve new functions. Lateral gene transfer moves genes between species. Chromosomal rearrangements alter gene structure and regulation. The latter three processes increase genomic variation, while transcription merely maintains existing genetic information.

Multiple choice

Which of the following statements about gene mutation is correct?

Mutation is the permanent change in the hereditary material, i.e., changes in the structure of chromosome or DNA. These changes in the DNA modify the sequence of amino acid in the protein of genes.

  1. It is the mutation from wild type to a new type.

  2. It is a change in the structure of gene.

  3. It is the mutation caused due to intracellular factors or due to background cosmic radiation.

  4. It is the mutations in germ cells or gametes or cells of germinal.

  5. It is the permanent change in the hereditary material.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Gene mutations or point mutations are changes in the structure of gene. Since genes are DNA segments, the gene mutations include changes in the number or arrangement of nucleotides. These are also known as ‘intragenic mutations’. Gene mutations alter or modify the information conveyed by the gene. Lethal, albinos, chlorophyll deficiencies, sickle cell anaemia, etc., are caused by gene mutations.

Multiple choice

Which of the following staements characterizes induced mutation?

Mutation is the permanent change in the hereditary material, i.e., changes in the structure of chromosome or DNA. These changes in the DNA modify the sequence of amino acid in the protein of genes.

  1. Mutations occurring in the somatic cells.

  2. Mutation caused due to intracellular factors or due to background cosmic radiation.

  3. Mutations in germ cells or gametes or cells of germinal.

  4. Mutation from wild type to a new type.

  5. Mutation introduced artificially or experimentally.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Induced mutations are introduced artificially or experimentally. Any physical or chemical agent, which introduces mutation is called a mutagen or mutagenic agent, physical (high or low temperature and the radiations) and chemical mutagens (mustard gas, colchicines, acridine dyes, nitrous acid, etc).

Multiple choice

Which of the following statements is/are false?

a. Heredity is the continuity of features from one generation to the next. b. Heredity information is present in the gametes of the parents. c. The male ovum fuses with the female sperm to form a zygote that gradually develops into an offspring.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option as this statement is false. The male sperm fuses with the female ovum to form a zygote that gradually develops into an offspring.

Multiple choice

Which of the following statements is/are false?

a. The process in which new species develop from the existing species is known as speciation. b. The gene that can decide the appearance of an organism only in the presence of another identical gene is called a recessive gene. c. If a sperm carrying X chromosomes fertilises an ovum carrying X chromosome, then the child born will be a boy.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option as this statement is false. If a sperm carrying X chromosomes fertilises an ovum carrying X chromosome, then the child born will be a girl.