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 statements is true?

  1. Mutation is more common in recessive condition.

  2. Mutation is more common in dominant condition.

  3. Mutation is constant in a population.

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene. It is more common in dominant condition as it is expressed here.

Multiple choice

Why offsprings are never found identical to their parents?

  1. Offsprings can be identical to only one of both the parents.

  2. All the offsprings are phenotypically different, but genotypically the same.

  3. Genetics do not play any role in this.

  4. They share the genes from both father and mother.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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Multiple choice

The term pleiotrophy refers to __________.

  1. combining genes from different species

  2. technique for identification of patterns that occur in DNA

  3. impact of single gene over several traits

  4. inheritance of complex characters that are determined by two or more genes

  5. a form of interaction between nonallelic genes in which one combination of such genes has a dominant effect over other combinations
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pleiotrophy refers to the control of several distinct and seemingly unrelated phenotypic effects (traits) by a single gene.

Multiple choice plant kingdom biology

Name the phenomenon that governs the following-

  1. Green beetels living in green bushes are not eaten by the crows
  2. All tall plants are obtained in $F _1$ generation, upon crossing pure tall and dwarf pea plant.

  3. Tails of mice were surgically removed for several generation ; still mice have tails in the following generation .

  4. Numbers of blue beetles on green bushes increase in a fur distant location than green beetles on green bushes, isolated by a river.

  5. A migrant beetle reproduces with the local population ; as a result genes of migrant beetle enter the new population.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Green beetles living in green bushes are camouflaged by their surroundings and are hence not eaten by the crows. This is a defense strategy employed by the beetles in order to escape predation. In the F1 generation crossing homozygous dominant (pure tall) and homozygous recessive (pure dwarf) plants will result in the heterozygous condition (Tt) with a phenotype of all tall plants as they will still have the dominant genotype. Removal of tails cannot be passed on from one generation to another, as it is not a heritable change and not a part of the genetic makeup of the organism. The isolation of an organism by a geographical barrier such as a river is called allopatry and hence governs the speciation of a sub-population such as blue beetles from green beetles. When a  migrant beetle reproduces with the local population the genes of migrant beetle enter the new population by the means of gene flow (also known as gene migration or allele flow) is the transfer of genetic variation from one population to another.  

So the correct answer is Green beetles living in green bushes are not eaten by the crows.

Multiple choice mendel's law of inheritance mendel's laws laws of inheritance mendel's laws of inheritance

How was Mendel's work ultimately reconciled with Darwin's theory of natural selection during the evolutionary synthesis in the 1930s and 1940s?

  1. Scientists recognized that once one thinks about species as populations, rather than individuals, there is no incompatibility between them.

  2. Mendel's theory was replaced by the mutation theory.

  3. It was recognized much of the variation we observe in nature is due to recombination, rather than mutation.

  4. a and c.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The modern synthesis reconciled Mendelian genetics with Darwinian evolution by showing that population genetics (a) and the understanding of genetic variation through recombination (c) provide the mechanism for natural selection.

Multiple choice commercial applications population - the increasing numbers and rising problem impact of depletion of natural resources population growth models depletion of resources

Carrying capacity is

  1. The capacity of an individual to produce young ones.

  2. Availability of resources in a given habitat to support a certain number of individuals of population, beyond which no further growth is possible.

  3. Gene frequency from one generation to next.

  4. Gene frequency in same generation.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The carrying capacity of an organism is the maximum population size of the species that the environment can sustain indefinitely beyond which there is no further growth. When the population reaches the carrying capacity then mortality becomes greater than natality.

Therefore, the correct answer is option B.

Multiple choice zoology molecular genetics one gene - one enzyme hypothesis component of the cell cell and cell organelles

Slight difference is identical twins support the hypothesis that ________________.

  1. Dominance may be incomplete

  2. Single gene may produce multiple effects

  3. The expression of genetic character is affected by environment

  4. They developed from separate fertilized eggs
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Identical twins share the exact same genetic makeup since they develop from a single fertilized egg. Therefore, any slight differences observed between them later in life are due to environmental influences acting on gene expression.