Biology · Science General

Evolution and Biological Adaptation

1,354 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

Which of the following, if true, would most strengthen the premise that viruses have evolved from bacteria?

Directions: Answer the given question based on the following passage:

One of the theories that have been under the serious consideration of the scientists and immunologists is that viruses have evolved from bacteria. Although viruses do not exist in fossilized form, and all our knowledge about the life form comes only from what we have come to know of them in the twentieth century, the view is not without merit. The bacteria origin theory, which states that the viruses evolved from bacteria that did not need to survive outside the host cell, and hence lost much of the genetic material needed for the same,  fills in some of the unexplained blanks in human knowledge.  Another theory states that viruses may have evolved from the ‘escaped bits and pieces of’ the DNA and the RNA of larger organisms.
Once a virus attaches itself to a specific molecule on the surface of the host cell, it penetrates the host cell by fusing with it or by another technique called endocytosis. Since a virus needs specific molecules to attach itself to, it means that its host selection is very specific. Once inside the host cell, the virus loses its capsid, or the outer shell, either by self generated enzymes or by enzymes secreted by the host and exposes its core viral nucleic acid. Since living cells produce all the necessary proteins from the various amino acids that are a part of the food supply, viruses take the host cell hostage and force it to synthesize proteins that the host cell does not need. Once synthesized, these new proteins come together later to form new virus cells. Once an army of invasive viruses is ready, enzymes produced by them usually burst the cell wall of the host cell, and the viruses release themselves into the body of the organism. Usually, the host cell death in cases of infections takes place by a process called apoptosis or cell suicide in which the phagocytic bodies produced by the immune system of the host organism are able to engulf the fragments of the host cell before the damage spreads to surrounding cells. However, some cells seemingly remain healthy and carry latent viruses and show few or no signs of infection for months or even years.

  1. The genetic structure of both organisms shows a certain level of similarity.

  2. When viruses are genetically modified to have the same genetic structure as bacteria, their survival rate in external environment improves remarkably.

  3. When bacteria are deprived of the same genetic material that the viruses lack, the bacteria can no longer be treated with antibiotics.

  4. Some virus strains, when mutated with bacteria genes, start reproducing like bacteria.

  5. When cultured together in a Petri dish, viruses often attack bacteria cells and parasite upon them.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

(1) Incorrect; 'a certain degree of similarity' is ambiguous and can be used to both strengthen and weaken the premise. (2) Correct; because incorporating a bacteria like genetic make up in the viruses gives them the ability to survive outside the host cell (like bacteria can), it strengthens the belief that viruses, if given the missing genes, are similar to bacteria. (3) Incorrect; the passage does not mention whether or not viral infections can be treated with antibiotics. (4) Incorrect; only 'some' viruses reproduce like bacteria when mutated with bacteria. It is possible that viruses have taken bacteria like properties but it cannot be inferred that viruses are like bacteria. (5) Incorrect; does not prove whether bacteria and viruses are related.

Multiple choice

All of the following can be inferred about the reproduction of viruses from the passage, except:

Directions: Answer the given question based on the following passage:

One of the theories that have been under the serious consideration of the scientists and immunologists is that viruses have evolved from bacteria. Although viruses do not exist in fossilized form, and all our knowledge about the life form comes only from what we have come to know of them in the twentieth century, the view is not without merit. The bacteria origin theory, which states that the viruses evolved from bacteria that did not need to survive outside the host cell, and hence lost much of the genetic material needed for the same,  fills in some of the unexplained blanks in human knowledge.  Another theory states that viruses may have evolved from the ‘escaped bits and pieces of’ the DNA and the RNA of larger organisms.
Once a virus attaches itself to a specific molecule on the surface of the host cell, it penetrates the host cell by fusing with it or by another technique called endocytosis. Since a virus needs specific molecules to attach itself to, it means that its host selection is very specific. Once inside the host cell, the virus loses its capsid, or the outer shell, either by self generated enzymes or by enzymes secreted by the host and exposes its core viral nucleic acid. Since living cells produce all the necessary proteins from the various amino acids that are a part of the food supply, viruses take the host cell hostage and force it to synthesize proteins that the host cell does not need. Once synthesized, these new proteins come together later to form new virus cells. Once an army of invasive viruses is ready, enzymes produced by them usually burst the cell wall of the host cell, and the viruses release themselves into the body of the organism. Usually, the host cell death in cases of infections takes place by a process called apoptosis or cell suicide in which the phagocytic bodies produced by the immune system of the host organism are able to engulf the fragments of the host cell before the damage spreads to surrounding cells. However, some cells seemingly remain healthy and carry latent viruses and show few or no signs of infection for months or even years.

  1. Viruses mutate the metabolic process of the host cell.

  2. Getting infected by a virus does not always annihilate the host cell.

  3. The virus undergoes metamorphosis once inside the host cell.

  4. Viruses reproduce by dividing themselves over and over.

  5. Viruses cannot replicate themselves unless inside a host cell.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

(1) Incorrect; the passage states that viruses force the host cell into manufacturing proteins that it does not need to survive. It means that viruses alter the natural metabolic process of the host cells. (2) Incorrect; the passage mentions that sometimes, the host cell survives for years after being infected. (3) Incorrect; the passage mentions that the virus loses its outer cell wall once inside the host cell. (4)Correct; the passage mentions that viruses reproduce by getting the host cell to produce proteins that it does not need and that these proteins later coalesce to form new virus cells. This information rules out the possibility of viruses reproducing by dividing themselves. (5) Incorrect; the passage mentions that viruses reproduce by getting inside the host cell.  

Multiple choice

The term 'hot dilute soup' has been used while explaining the theory of

  1. special creation

  2. chemical evolution

  3. spontaneous generation

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

The term 'hot dilute soup' was coined by J.B.S. Haldane to describe the primordial environment where organic molecules formed, which is a central concept in the theory of chemical evolution (Oparin-Haldane hypothesis).

Multiple choice

Which one provides correct sequence of events in origin of new species according to Darwinism? A) Natural selection B) Variations and their inheritance C) Survival of the fittest D) Struggle for existence

  1. ABCD

  2. BCAD

  3. CDAB

  4. DBCA

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

According to Darwinism, the sequence is: (D) Struggle for existence, (B) Variations and their inheritance, (C) Survival of the fittest, and (A) Natural selection. This leads to the adaptation of the population.

Multiple choice

Which one does not favour Lamarckian concept of inheritance of acquired characters?

  1. Lack of pigment in cave dwellers.

  2. Absence of limbs in snakes.

  3. Presence of webbed toes in aquatic birds.

  4. Melanization of Peppered Moth in industrial areas.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The melanization of the Peppered Moth is a classic example of natural selection acting on existing genetic variation, not the inheritance of acquired characters as proposed by Lamarck.

Multiple choice

According to Lamarckism, long necked giraffes evolved because

  1. nature selected only long necked animals

  2. of stretching of necks by short ones over many generations

  3. humans preferred long necked animals

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

According to Lamarckism, long necked giraffes evolved because of stretching of necks by short ones over many generations. 

Multiple choice

Weisman cut off the tails of mice, generation after generation but tails neither disappeared nor shortened, showing that

  1. Darwin was correct

  2. Tail is an essential organ

  3. Mutation theory is wrong

  4. Acquired characters are not inherited
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

August Weismann's experiment with mice tails demonstrated that physical changes acquired during an organism's life are not passed on to offspring, thereby refuting Lamarck's theory of inheritance of acquired characters.

Multiple choice

The cornerstone of Darwin's theory is

  1. inheritance of acquired characters

  2. higher productivity

  3. natural selection

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Natural selection is the fundamental mechanism proposed by Charles Darwin to explain how evolution occurs and how species adapt to their environments.

Multiple choice

Which of the following is a missing link in evolution?

  1. Peripatus

  2. Limulus

  3. Pheretima

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

Archaeopteryx is widely recognized as a classic missing link (transitional fossil) between non-avian dinosaurs and birds, possessing features of both groups. Peripatus is a link between Annelida and Arthropoda, not a missing link in the same sense.

Multiple choice

Select the pair that does not match.

  1. Linnaeus -Species are dynamic entities

  2. Darwin's finches - Unique to Galapagos

  3. Hugo de Vries - Evolution is discontinuous

  4. Coacervates -Aggregates of organic compounds bound by organic membrane
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Linnaeus is known for the binomial nomenclature system and the concept of species as fixed and immutable entities, not dynamic ones. The other pairings correctly describe their respective evolutionary concepts.

Multiple choice

Evolutionary history of an organism is known as

  1. Ancestry

  2. Paleontology

  3. Ontogeny

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

Phylogeny refers to the evolutionary development and diversification of a species or group of organisms, often represented as a tree showing ancestral relationships.

Multiple choice

Which one of the following phenomena supports Darwin's concept of natural selection in organic evolution?

  1. Development of transgenic animals.

  2. Production of 'Dolly', the sheep by cloning.

  3. Prevalence of pesticide resistant insects.

  4. Development of organs from 'stem cells' for organ transplantation.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The emergence of pesticide resistance in insects is a direct observation of natural selection in action, where individuals with a random mutation that confers resistance survive and reproduce, passing the trait to offspring.

Multiple choice

Presence of gill slits in the embryos of all vertebrates support the theory of

  1. organic evolution

  2. biogenesis

  3. metamorphosis

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

The presence of gill slits in vertebrate embryos is a classic example used to support the recapitulation theory (biogenetic law), which suggests that an organism's development (ontogeny) repeats its evolutionary history (phylogeny).

Multiple choice

Evolutionary divergence is characterized by

  1. development of dissimilar characters in closely related groups.

  2. development of a common set of characters in the groups of different ancestry.

  3. development of characters by random mating.

  4. development of characters by inbreeding.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Evolutionary divergence (divergent evolution) occurs when a common ancestor gives rise to different species that adapt to different environments, leading to the development of dissimilar characters in closely related groups.