Tag: mutational theory of evolution

Questions Related to mutational theory of evolution

Which one of the following was the contribution de Vries?

  1. Theory of natural selection

  2. Law of segregation

  3. Theory of mutation

  4. Law of dominance


Correct Option: C
Explanation:

Mutations are the raw materials of evolution. 

It is sudden heritable change in germplasm.

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


Correct Option: C
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.

The major cause of evolution of genes and protein is

  1. Point mutation

  2. Chromosomal aberration

  3. Sexual reproduction

  4. Gene duplication and divergence


Correct Option: A
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.

Hugo de Vries formulated the "Mutation Theory" based on the experiments he conducted on 

  1. Althea rosea

  2. Pisum sativum

  3. Drosophila melanogaster

  4. Oenothera lamarckiana


Correct Option: D
Explanation:

Hugo de Vries, a Dutch Botanist formulated the Mutation theory. According to him, "new species are not formed by continuous variations but by the sudden appearance of variations", which he named as variations. He stated that mutations are heritable and persisted in successive generations.

He conducted his experiments on Oenothera lamarckiana (Evening Primrose) and found several aberrant types. These plants appeared to be new species, Hugo de Vries suggested from his experiments that new types of inherited characteristics may appear suddenly without any previous indication of their previous in the race. He believed that Mutation causes evolution and not the minor heritable variations which were mentioned by Darwin. Hence option D is correct.

Mutations were first reported by De Vries in

  1. Pea

  2. Datura

  3. Oenothera lamarckiana

  4. None of the above


Correct Option: C
Explanation:

De Vries discovered new forms among a display of the evening primrose (Oenothera lamarckiana) growing wild in an abandoned potato field. Taking seeds from these, he found that they produced many new varieties in his experimental gardens; he introduced the term mutations for these suddenly appearing variations.

So, the correct answer is 'Oenothera lamarckiana'.

Hugo de Vries worked on the plant :

  1. Garden Pea/ Pisum sativum

  2. Sweat Pea / Lathyrus odoratus

  3. Primula sinesis

  4. Evening Primrose / Oenothera lamarckiana


Correct Option: D
Explanation:

Hugo de Vries had discovered different morphological forms/abberants/variations in primrose/ Oenothera lamarckiana 

So, the correct option is' 'evening primrose/ Oenothera Lamarckiana'

De Vries theory of mutation is :

  1. Opposed to natural selection theory.

  2. Not opposed to natural selection theory.

  3. Opposed to germplasm theory

  4. Opposed to Lamrck's theory


Correct Option: B
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 'Not opposed to natural selection theory'

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

  1. Genetic drift

  2. Adaption

  3. Mutation

  4. Natural selection


Correct Option: C
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'.

Mutation theory based on work over Oenothera lamarckiana was given by,

  1. Morgan

  2. Mendel

  3. De Vries

  4. Muller


Correct Option: C
Explanation:

Hugo de Vries proposed the mutation theory .He worked on a flowered evening primrose, he observed the sudden appearance of several expressions

So, the correct answer  is 'De Vries'

Choose the wrong statement with reference to mutation theory :

  1. Mutations accumulate over generations.

  2. There are no intermediate stages.

  3. Mutants are markedly different from parents.

  4. Mutations are subjected to natural selection.


Correct Option: D