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 zoology biodiversity, classification and conservation levels of biodiversity environmental conservation and biodiversity biodiversity on earth and in india

The interbreeding individuals of a species showing continuous distribution are

  1. Endemic

  2. Deme

  3. Cline

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

In biology, a deme is a term for a local population of organisms of one species, that actively interbreed with one another and share a distinct gene pool. When demes are isolated for a very long time they can become distinct subspecies or species. The term 'deme' is mainly used in evolutionary biology and is often used as a synonym for population. In evolutionary computation a "deme" often refers to any isolated subpopulation subjected to selection as a unit rather than as individuals. 

Multiple choice zoology biodiversity, classification and conservation levels of biodiversity environmental conservation and biodiversity biodiversity on earth and in india

A continental population of insects has blue, red, green, and black variations. The color is controlled by the interaction of two genes, one with two alleles, the other with three alleles.
A piece of driftwood carrying two green insects and five red insects floats in the ocean for several days and washes up on a small island where the insect species did not previously live. The seven insects establish a new population on the island that increases in number significantly over several generations.
Which of the following statements correctly compares the island population with the original mainland population?

  1. Red is dominantly inherited in the island population, while on the mainland green is dominant.

  2. The island population has lower genetic diversity than the mainland population.

  3. The island population is more likely to experience competition with other insect species than the mainland population.

  4. The island population size is increasing, while the mainland population is decreasing.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is given that out of blue, red, green and black variations of insects, only red and green insects established a new population on the new island. Since, these four colors are controlled by two genes, new population could have either of colour of insects. It is an example of founder effect. The island population will have lower genetic diversity than the mainland population because small populations usually have less genetic diversity than large population.

Thus, the correct answer is 'The island population has lower genetic diversity than the mainland population.'

Multiple choice biology selection and evolution ethology animal behaviour natural selection

Identify the true statement:

  1. Mutations are adaptive and occur according to the changes in the environment.

  2. Genetic drift is the random fluctuations in the allele frequencies in large population.

  3. Natural selection is the difference in reproduction that causes difference in the contribution of alleles of next generation.

  4. Mutations are directional and occurs in the individuals of a population.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Natural selection is defined by differential reproductive success based on heritable traits, which leads to changes in allele frequencies over generations.

Multiple choice biology selection and evolution ethology animal behaviour natural selection

Choose the correct answers from the alternatives given.
Populations of peppered moths (Biston betularia) of England changed from 1% dark and 99% grey individuals to 99% dark and 1% light 
individuals between 1848 and 1898. The selective agent causing the change was

  1. humans

  2. birds

  3. lichens on tree bark

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

Due to Industrial melanism, refers to the evolution of dark body colours in animal species that live in habitats blackened by industrial soot. The phenomenon has been documented in numerous species that hide from predators by blending in with their backgrounds. The main predator is bird.

So the correct option is B, birds.

Multiple choice biology selection and evolution ethology animal behaviour natural selection

Choose the correct answers from the alternatives given.
Natural selection may occur when there are

  1. heritable traits

  2. differences in the adaptiveness of forms of traits to prevailing environmental conditions

  3. differences in survival and reproduction among individuals that differ in one or more traits

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Natural selection is the process where organism with favorable traits are more likely to reproduce. In doing so, they pass on these traits to the next generation. Over time this process allows organism to adapt to their environment.

Hence, the correct answer is 'all of the above'

Multiple choice zoology origin of life and organic evolution neo darwinism mechanism of evolution other theories of evolution

Which of the following is the cause of speciation?

  1. Point mutation

  2. Gross mutation

  3. Both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Point mutation is a type of mutation that causes a single nucleotide base change, insertion, or deletion of the genetic material, DNA or RNA.
Gross mutations also known as Chromosomal mutations are the mutations that alter the structure of the individual chromosome. Both Point mutation and gross mutation is the cause of speciation which is the evolutionary process by which reproductively isolated biological populations evolve to become distinct species. Thus, the correct answer is option D.
Multiple choice zoology origin of life and organic evolution neo darwinism mechanism of evolution other theories of evolution

There would be no evolution, if 

  1. The inheritance of acquired characters did not take place.

  2. Somatic variations were not inheritable.

  3. Gene variations were not found among members of population.

  4. Somatic variations would not transform into germinal variations.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Evolution relies on genetic variation within a population. If all members were genetically identical, natural selection would have no variation to act upon, halting the evolutionary process.

Multiple choice zoology origin of life and organic evolution neo darwinism mechanism of evolution other theories of evolution

Genetic variation in a population that determines the phenotype is referred by its

  1. Fitness

  2. Heritability

  3. Limited environmental resources

  4. Overproduction of offspring

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

Heritability is the part of phenotype variation in a population. This can be attributed to genetic variations in the organisms in that population. This is the factor which describes the chances of evolution occurring in that population on the basis of the genetic differences. 

Thus, the correct answer is option "Heritability'.

Multiple choice zoology origin of life and organic evolution neo darwinism mechanism of evolution other theories of evolution

The mechanism in which mating is prevented between individuals of different groups due to structural differences is known as

  1. Geographical isolation

  2. Mechanical isolation

  3. Temporal isolation

  4. Hybrid sterility

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

Physical separation of groups preventing the gene flow between them leads to geographical isolation. Incompatible differences in reproductive structures leading to prevention of cross-fertilization refer to as mechanical isolation. Different periods of attainment of sexual maturity lead to temporal isolation. Hybrid sterility is one of the post-zygotic isolation. Incompatible premating behaviour leading to no attraction between groups for mating is termed as behavioural isolation. Thus, the correct answer is B.

Multiple choice zoology origin of life and organic evolution neo darwinism mechanism of evolution other theories of evolution

Which of the following statements concerning genetic variation is most accurate?

  1. The process of natural selection directly creates genetic variation.

  2. Changes in the environment of a population stimulate mutation and genetic change in that population.

  3. Genetic variation must be present in a population before natural selection can act upon organisms in that population.

  4. The higher the average heterozygosity in a population, the less genetic variation in the gene pool.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Genetic variation results in the evolution. It results due to mutation in the genetic material resulting in a permanent change. The process of natural selection directly creates genetic variation. Natural selection will change the allele frequencies in the population. This in turn will create genetic variation due to loss of certain alleles during natural selection. Mutation and genetic changes occur spontaneously and change in the environment does stimulate it. The higher the heterozygosity in a population, the higher genetic variation is seen in the population. 

Thus, the correct answer is 'The process of natural selection directly creates genetic variation.'

Multiple choice zoology origin of life and organic evolution neo darwinism mechanism of evolution other theories of evolution

Which of the following best describes natural selection?

  1. A populations gene frequencies change over time.

  2. Individuals develop useful adaptations in response to environmental stress.

  3. Individuals with the most favorable traits survive and reproduce.

  4. Some individuals in a population will survive longer than other members of the population.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Natural selection is a process governed by changes in environmental factors, these factors produce stress on the organisms. That compels the organisms to undergo changes, in case the organism undergoes changes suitable to the environment, that is, it is suited to survive in the environment will also pass on those traits to the next generation, until the next change occurs. This is natural selection.

So, the correct answer is 'Individuals with the most favorable traits survive and reproduce'

Multiple choice zoology origin of life and organic evolution neo darwinism mechanism of evolution other theories of evolution

Which of the following is related with reproductive isolation?

  1. Genetic isolation

  2. Temporal isolation

  3. Behavioural isolation

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Genetic isolation exists when two populations are so different genetically that they cannot produce fertile offspring (or any offspring at all).
Temporal isolation is genetic isolation achieved due to temporal differences in breeding.
Behavioral

Isolation is a form of reproductive isolation in which two populations

have differences in courtship rituals or other types of behavior that

prevents them from interbreeding




Multiple choice zoology origin of life and organic evolution neo darwinism mechanism of evolution other theories of evolution

Which of the following variations are temporary and have nothing to do with the last or next generation?

  1. Hereditary variations

  2. Discontinuous variations

  3. Environmental variations

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

Environmental variations are those variations which are merely due to environment. These variations are temporary and have nothing to do with the next generation. Hereditary variations are those variations which transfer to next generation. Discontinuous variations are sudden changes in organism which are also heritable.

So, the correct answer is 'environmental variations'