Tag: the paths traversed by life

Questions Related to the paths traversed by life

The major cause of evolution of genes and protein is

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

  1. Point mutation

  2. Chromosomal aberration

  3. Sexual reproduction

  4. Gene duplication and divergence

Show answer
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 

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

  1. Althea rosea

  2. Pisum sativum

  3. Drosophila melanogaster

  4. Oenothera lamarckiana

Show answer
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

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

  1. Pea

  2. Datura

  3. Oenothera lamarckiana

  4. None of the above

Show answer
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 :

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

  1. Garden Pea/ Pisum sativum

  2. Sweat Pea / Lathyrus odoratus

  3. Primula sinesis

  4. Evening Primrose / Oenothera lamarckiana

Show answer
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 :

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

  1. Opposed to natural selection theory.

  2. Not opposed to natural selection theory.

  3. Opposed to germplasm theory

  4. Opposed to Lamrck's theory

Show answer
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 :

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

  1. Genetic drift

  2. Adaption

  3. Mutation

  4. Natural selection

Show answer
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,

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

  1. Morgan

  2. Mendel

  3. De Vries

  4. Muller

Show answer
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 :

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

  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.

Show answer
Correct Option: D

Mutations are considered raw materials of evolution because they :

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

  1. Cause death of organism

  2. Contribute to new variations

  3. Are stable

  4. Random

Show answer
Correct Option: B
Explanation:
Mutations are considered raw material to evolution, as mutations change the genetic material giving rise to  variations an accumulation of variations eventually leads to evolution.
So, the correct answer is 'Contribute to new variations'

A theory explaining the mechanism of evolution based on change of gene structure was put forward by :

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

  1. De Vries

  2. Darwin

  3. Lamarck

  4. Wallace

Show answer
Correct Option: A
Explanation:
  • The theory which took change of gene structure called mutation under consideration was put forward by Hugo De Vries.
  • He his work on evening primrose suggested that variations occurred due to mutations.
  • Mutations are random and directionless while the variations that Darwin talked about were small and directional. Hugo de Vries gave the name saltation (single step large mutation) to the mutations which brought about speciation.
So, the correct answer is 'De Vries'