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 zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

According to the theory of mutation by Hugo de Vries

  1. Only small mutation takes part in variation

  2. Only large mutation takes part in variation

  3. Both small and large mutation cause variation in species

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

According to Devries the evolution is very fast like horse running

movement, but not slowly like snails movement as said by Darwin.

Devries also said that there are no middle forms between the ancestor

and new species.

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

The major cause of evolution of genes and protein is

  1. Point mutation

  2. Chromosomal aberration

  3. Sexual reproduction

  4. Gene duplication and divergence
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Point mutation refers to the single nucleotide change in genes or single amino acid change in proteins. These changes lead to variability in population and ultimately leads to evolution. Meiosis during sexual reproduction produces new combination of already existing alleles and genes through crossing over but does not creates any new alleles. Gene duplication and divergences are rare events as compared to point mutation. Chromosomal aberrations will bring changes in entire chromosome, not individual genes and / or proteins.

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

Forthcoming generation will be less adaptive than the present generation due to :

  1. Genetic drift

  2. Adaption

  3. Mutation

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

According to De Vries theory of evolution:

  • Mutation or discontinuous variation is the raw material of evolution.
  • The mutation appears suddenly and produced their effect immediately.
  • Mutants are different from the parents and there is no intermediate stage between the two.
  • The same type of mutation can appear in several individuals of a species.
  • Mutation can appear in all direction and all mutations are the inheritance
  • Useful mutations are selected by nature an lethal mutations are eliminated.

So, the correct option is 'Mutation'.

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

Theory of mutation by a De Vries considers that :

  1. Only small mutations take part in developing variations

  2. Only large mutations take part in developing variations.

  3. Both small and large mutations cause variations.

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

Hugo de Vries after his work on Evening Primose, put forth his theory explaining the structural changes in gene structures, called mutation as the cause of variations. Only large, single step and abrupt mutation termed as saltation are capable enough to drive the process of evolution.

So, the correct option is 'Only large mutations take part in developing variations'.

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

To be evolutionary successful, mutation must occur in :

  1. Germplasm DNA

  2. Somatoplasm DNA

  3. Plasma protein

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

  • For a mutation to be evolutionary successful, it must occur in Germplasm DNA since germline mutations are the only one that can be passed on to offspring, when either a mutated sperm or oocyte come together to form a zygote.
  • After this fertilization event occurs, germ cells divide rapidly to produce all of the cells in the body, causing this mutation to be present in every somatic and germline cell in the offspring; this is also known as a constitutional mutation.
So, the correct option is 'Germplasm DNA'.

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

Mark the correct set.

  Column I  Column II
1. Sewall Wright A.  Mutation
2. Hugo de Vries   B.  Natural selection
3. Darwin C.  Industrial melanism
4. Kettlewell  D.  Genetic drift
5. Hardy-Weinberg E.  Genetic equilibrium

  1. A- 2, B- 3, C- 4, D- 1, E- 5

  2. A- 1, B- 3, C- 5, D- 2, E- 4

  3. A- 3, B- 2, C- 1, D- 4, E- 5

  4. A- 1, B- 2, C- 3, D- 4, E- 5
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Hugo de Vries, a Dutch botanist, one of the independent rediscoveries of Mendelism, put forward his views regarding the formation of new species which are due to mutations. 
In 1859, Charles Darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. He defined natural selection as the "principle by which each slight variation if useful, is preserved".
Industrial melanism is an effect of urban pollution prominent in many species of arthropods. It is the phenomenon of an organism evolving dark pigmentation when exposed to an environment polluted by dark soot deposit and sulfuric buildup from industrial pollution. The first important experiments on the peppered moth were carried out by Bernard Kettlewell at Oxford University.
Genetic drift or allelic drift is the change in the frequency of a gene variant (allele) in a population due to random sampling. Sewall wright was the chief developer of the mathematical theory of genetic drift.
Genetic equilibrium describes the condition of an allele or genotype in a gene pool (such as a population) where the frequency does not change from generation to generation. It is also called as Hardy-Weinberg equilibrium. Therefore, the correct answer is option A.
Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

For evolutionary success, mutation must occur in

  1. Somatic RNA

  2. Somatic DNA

  3. Germplasm DNA

  4. Germplasm RNA
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Germplasm is living hereditary assets, for example, seeds or tissues that are kept up with the end goal of creature and plant reproducing, protection, and other research employment. Germplasm accumulation is vital for the support of organic decent variety and sustenance security.

So, the correct option is 'Germplasm DNA'.

Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

De Vires called mutants

  1. Variants

  2. Elementary species

  3. New species

  4. Sports
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Hugo de Vries gave mutation theory in 1901 stating that evolution occurs through discontinuous variation or sudden change due to elementary species (later called mutants) which passed on to generations. Thus, the correct answer is 'elementary species.'
Multiple choice zoology environmental factors soil-nature climate factors abiotic components organisms and environment

Ecotype is a type of species in which environmentally induced variations are

  1. Temporary

  2. Genetically fixed

  3. Genetically not related

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

An ecotype is a distinct population within a species that has adapted to specific local environmental conditions. These adaptations are genetically fixed, meaning they are inherited and persist even if the organism is moved to a different environment.

Multiple choice population and how it changes human population ecology and environment zoology

The transient population between two adjacent ecotypes is called as

  1. Deme

  2. Polytypic

  3. Cline

  4. Hybrid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The diverse climate and the seasonal variations lead to the formation of several zones having flora and fauna with the phenotypic difference. An ecocline or simply cline describes an ecotone in which a series of biocommunities display a continuous gradient. The term was coined by the Huxley in 1938. Clines are the source of genetic and phenotypic variations. It consists of different forms of species, that exhibit gradual phenotypic and / or genetic differences over a geographical area, typically as a result of  diverse environmental condition. 

Multiple choice population and how it changes human population ecology and environment zoology

Two populations of a species of pine tree are located on opposite sides of a mountain range. The two populations are genetically similar to each other.
An invasive beetle infestation kills 80% of the trees on the west side of the range. The beetle population does not spread to the eastern side of the range, and the east tree population does not experience any beetle related loss. After the infestation, the western tree population increases in size again.
What is the expected outcome of genetic testing comparing the two populations?

  1. The genetic diversity of the west population is higher than the east population.

  2. The phenotypic variation of the west population is higher than the east population.

  3. The two populations are less genetically similar than they were prior to the beetle infestation.

  4. The two populations remain genetically similar.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Due to beetle infestation, 80% of the trees on the west side of the range were killed. This will result in the alteration of allele frequencies. Certain alleles are lost during infestation. In the small population of the west side, genetic diversity is less compared to that of a large population in the east. Due to less genetic diversity, phenotypic variations will also be lower on the west side. Hence, the two side of populations will be less genetically similar than the earlier. 

Thus, the correct answer is 'The two populations are less genetically similar than they were prior to the beetle infestation.'

Multiple choice population and how it changes human population ecology and environment zoology

For natural selection to occur, which of the following must be true for a population of organisms?

  1. Phenotypic variations must be based on genetic variations rather than on varying environmental conditions.

  2. The population must be occupying the same niche as another local population.

  3. Organisms in the population must be capable of sexual reproduction.

  4. Food resources must be limited.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Evolution takes place due to various reasons like natural selection, mutation, genetic drift. Phenotypic variations must be based on genetic variations rather than on varying environmental conditions. Sexual reproduction results in the genetic variation but does not affect the natural selection. Also, limited food resources may drive natural selection but is not the reason for natural selection to occur.

Thus, the correct answer is 'Phenotypic variations must be based on genetic variations rather than on varying environmental conditions.'

Multiple choice zoology plant reproduction different modes of reproduction sexual and asexual reproduction lifespan, reproduction and variation

Offspring formed by sexual reproduction exhibit more variation than those formed by asexual reproduction because

  1. Sexual reproduction is a lengthy process

  2. Gametes of parents have qualitatively different genetic composition

  3. Genetic material comes from parents of two different species

  4. Greater amount of DNA is involved in sexual reproduction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Asexual reproduction is a type of reproduction by which offspring arise from a single organism, and inherit the genes of that single parent only. During sexual reproduction, fertilization creates a single-celled zygote which includes genetic material from both gametes. Therefore, the complex mixture of genetic material causes a great variation in the offspring. 
So, the correct option is 'Gametes of parents have qualitatively different genetic composition'.



Multiple choice zoology plant reproduction different modes of reproduction sexual and asexual reproduction lifespan, reproduction and variation

________ is the disadvantage of asexual reproduction

  1. Repid reproduction

  2. Lack of genetic variation

  3. Both a and b

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

In asexual reproduction only one parent is involved so there is no fusion of two cells, the daughter cells produced by asexual reproduction are genetically identical to the parent cells variations enable organisms to adopt and survive in changing environment and it helps to prevent the complete extinction of specters. so lack of genetic variation is the disadvantage.
 Whereas rapid reproduction is the advantage of asexual reproduction.

So, the correct answer is ' Both a and b'.