Biology · Science General

Evolution and Biological Adaptation

1,288 Questions

Evolution and biological adaptation focus on natural selection, speciation events, and how organisms adjust to environmental changes over time. These foundational biology concepts appear frequently in general science sections of civil services and school board examinations. Use these questions to study evolutionary theories, ancestral traits, and the fossil record.

Natural selection mechanismsSpeciation event examplesBiological adaptation traitsPanspermia hypothesis conceptsFossil record analysisMate selection theories

Evolution and Biological Adaptation Questions

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

Which is the most important factor for evolution of new species?

  1. Geographic isolation

  2. Extensive in-breeding

  3. Extensive out-breeding

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

Geographical isolation: The separation of two populations of the same species or breeding group by a physical barrier, such as a mountain or body of water. 

Geographical isolation may ultimately lead to the populations becoming separate species by adaptive radiation. In the fruit fly example, some fruit fly larvae were washed up on an island, and speciation started because populations were prevented from interbreeding by geographic isolation. Scientists think that geographic isolation is a common way for the process of speciation to begin. Rivers change course, mountains rise, continents drift, organisms migrate and what was once a continuous population is divided into two or more smaller populations. It doesn't even need to be a physical barrier like a river that separates two or more groups of organisms. It might just be unfavourable habitat between the two populations that keeps them from mating with one another. This is one of the most important factor for speciation. Thus, option A is correct.

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

Mutation theory cannot explain 

  1. Mimicry

  2. Industrial melanism

  3. Connecting link

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

  • Hugo de Vries in 1901 put forward a theory of evolution, called mutation theory. The theory states that evolution is a jerky process where new varieties and species are formed by mutations (discontinuous variations) that function as a raw material of evolution.
  • Mutation theory can not explain the phenomenon of mimicry (i.e. the resemblance between mimic and model), protective coloration and relationship between position of nectaries in flowers and length of proboscis of insects that pollinate them.

Therefore, the correct answer is option A.

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

The most accepted theory of organic evolution is

  1. Natural selection theory

  2. Phase theory

  3. Synthetic theory

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

In the 20th century conception of evolution being caused by a number of complex and often interacting processes. This is essentially a combination of Darwin's concept of natural selection, Mendel's basic genetics, along with the facts and theories of population genetics and molecular biology. So, this theory explains almost all factors related to organic evolution. Hence, this is the most accepted theory as compared to others.

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

Which is not a pre-zygotic isolation mechanism?

  1. Geographical isolation

  2. Ecological isolation

  3. Seasonal isolation

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

Sterility of hybrid is never a pre - zygotic isolation mechanism.Hybrid zygotes sometimes develop into adults, such as mules (hybrids

between female horses and male donkeys), but the adults fail to develop

functional gametes and are sterile.

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

One of the important consequence of geographical isolation is

  1. No change in the isolated fauna

  2. Preventing Speciation

  3. Speciation through reproductive isolation

  4. Random creation of new species
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If species are geographically isolated and separated for long period of time, they may lose ability to interbreed and produce fertile offsprings. Thus leading to formation of new species

So, the correct answer is 'speciation through reproductive isolation'

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

As per modern synthetic theory organic evolution depends upon

  1. Mutation, reproductive isolation and natural selection

  2. Gene recombination and natural selection

  3. Mutation and natural selection

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

The synthetic theory of evolution is based on gene mutation, gene recombination, natural selection, genetic drift, isolation.(Other factors-migration, hybridisation,chance)

  1. Mutation, recombination, natural selection, genetic drift and isolation are involved in natural selection.
  2. Mutation is an important source of variation that fulfills gene pool and remains a base to polygenic or multi-factorial inheritance.
  3. The process of micro-evolution is governed by natural selection and gene flow is affected by reproductive isolation.
  4. Evolution is governed by genetic drift.
  5. Micro-evolutionary factors create new species.

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

Isolation leads to ________.

  1. Species differentiation

  2. Evolutionary divergence

  3. Formation of analogous structures.

  4. Formation of similar traits
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Isolation, particularly reproductive or geographic, prevents gene flow between populations. This allows populations to diverge genetically, eventually leading to the formation of new species.

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

Modern theory of evolution is based on :

  1. Mutations

  2. Genetic recombination

  3. Natural selection

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

Synthetic theory is considered as Modern theory and the main contributor of this theory was G.L.Stebbins. They considered 5 factors, responsible for organic evolution. They are as follows

1.Mutation 
2.Genetic recombinantion
3.Chromosomal aberration
4.Reproductive isolation
5.Natural Selection
So, the correct answer is 'All the above'

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

Which one does not help in understanding evolution?

  1. Genetic variation

  2. Natural selection

  3. Embryogenesis

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

For understanding Evolution, we consider-

Genetic variation- These are changes in genes that are heritable, which might become useful for some, who get better adapted with habitat. 
Natural Selection- It is the process in which the individuals who are better suited for the environment leave behind more offsprings than the ones who are less suited. It is a key component in studying evolution.
Embryogenesis- It is the process and formation of an embryo. With the help of this, we're able to make links with different species on the basis of their embryos. 
Isolation is an important component in the process of Speciation. It doesn't help in understanding evolution. Hence, Option D is correct.

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

The phenomenon 'ontogeny repeats phylogeny' is explained by

  1. Recapitulation theory

  2. Inheritance theory

  3. Mutation theory

  4. Natural selection theory
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Biogenetic law or Recapitulation theory was given by Ernst Haeckel in 18661866. It states that 'ontogeny repeats phylogeny'. Ontogeny is the life history of an organism while phylogeny is the evolutionary history of the race of that organism. This means that an organism repeats its ancestral history during its development.
So, the correct answer is 'Recapitulation theory'.
Multiple choice zoology origin of life and organic evolution neo darwinism mechanism of evolution other theories of evolution

Which of these is a premating isolating mechanism?

  1. Habitat isolation

  2. Temporal isolation

  3. Gamete isolation

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

In order for different species to diverge from common ancestors and drive evolution, reproductive isolation must occur. There are several types of reproductive isolation that lead to speciation. 

One major type is called prezygotic isolation and it happens before fertilization occurs between gametes. Basically, prezygotic isolation keeps different species from sexually reproducing. If individuals cannot reproduce, they are considered to be different species and diverge on the tree of life. There are several types of prezygotic isolation that range from incompatibility of gametes, to behaviors that result in incompatibility, and even a type of isolation that keeps individuals from physically being able to breed.
Mechanical- Mechanical isolation is probably the simplest concept, that keeps individuals from being able to reproduce offspring with each other. Simply put, mechanical isolation is the incompatibility of sexual organs. They just do not fit together. It may be the shape of the reproductive organs not being compatible, or size differences that prohibit the individuals from coming together.In plants, mechanical isolation is a bit different. Since size and shape are irrelevant to reproduction in plants, mechanical isolation is usually due to the use of a different pollinator for the plants.
Habitat isolation- Even very closely related species have a preference of where they live and where they reproduce. Sometimes, the preferred locations of the reproductive events are not compatible and this leads to what is known as habitat isolation. Obviously, if individuals of two different species live nowhere near each other, there will be no opportunity to reproduce and reproductive isolation will lead to even more speciation.
Temporal isolation- Different species tend to have different breeding seasons. The timing of when females are fertile leads to temporal isolation. Similar species may be physically compatible, but may still not reproduce due to mating seasons being different times of the year. If the females of one species are fertile during a given month, but the males are not able to reproduce at that time of the year, then there will be reproductive isolation between the two species.
Gametic isolation- During sexual reproduction, the female egg is fused with the male sperm and together they create a zygote. If the sperm and egg are not compatible, this fertilization cannot occur and the zygote will not form. The sperm may not even be attracted to the egg due to the chemical signals released by the egg. Other times, the sperm just cannot penetrate the egg because of its own chemical make up. Either one of these reasons is sufficient enough to keep fusion from happening and the zygote will not form.

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

In which of the following mechanisms fertile offsprings are not produced as a result of mating between groups?

  1. Geographical isolation

  2. Mechanical isolation

  3. Temporal isolation

  4. Hybrid sterility

  5. Behavioral isolation

  6. Both C and D
Reveal answer Fill a bubble to check yourself
F Correct answer
Explanation

Abnormal distributions to the gametes of whole chromosomes, chromosome segments or combinations of genes lead to hybrid sterility. Geographical, mechanical, temporal and behavioral isolations are pre zygotic barriers and prevent mating between groups by one or other means and hybrid is not produced. Thus, the correct answer is D.

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

The evolution of a species is based upon sum total of adaptive changes preserved by 

  1. Natural selection

  2. Isolation

  3. Speciation

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

A) Darwin's characteristic choice is the procedure by which nature remunerates those people betters adjust to their surroundings with survival and regenerative achievement. It works at the dimension of qualities, areas of DNA that encode for proteins filled in as the product of life. 

B) The instrument of regenerative detachment is a gathering of developmental components, practices and physiological procedures basic for speculation. They keep individuals from various species from delivering posterity or guarantee that any posterity is sterile. 

C) Speciation is the developmental procedure by which populaces advanced to end ups particular species. 

D) Human Conversation is the intelligent correspondence between at least two individuals.

So, the correct option is 'Isolation'.