Tag: the paths traversed by life

Questions Related to the paths traversed by life

The fountain head of evolution is 

  1. Mutations

  2. Acquired characters

  3. Natural selection

  4. Sexual reproduction


Correct Option: A
Explanation:

A transformation is an adjustment in DNA, the inherited material of life. A creature's DNA influences what it looks like, how it carries on, and its physiology. So an adjustment in a living being's DNA can cause changes in all parts of its life. Changes are basic to advancement; they are the crude material of hereditary variety.                                                                             

So, the correct option is 'Mutations'.

For evolutionary success, mutation must occur in

  1. Somatic RNA

  2. Somatic DNA

  3. Germplasm DNA

  4. Germplasm RNA


Correct Option: C
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'.

De Vires called mutants

  1. Variants

  2. Elementary species

  3. New species

  4. Sports


Correct Option: B
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.'

According to De Vries' theory, evolution is

  1. Discontinuous

  2. Jerky

  3. Continuous and smooth

  4. Both A and B


Correct Option: D
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 'Both A and B'.

The mechanism of origin of variations was first suggested by

  1. Lamarck

  2. Darwin

  3. De Vries

  4. Mendel


Correct Option: C
Explanation:

Variation was first explained by Hugo De Vries in 1901 while studying evening primrose species. He suggested that species are not formed by continuous changes but with sudden changes called mutation. Thus, the correct answer is 'De Vries.'

De Vires' Oenothera lamarckiana was 

  1. Complex heterozygote with anomalous chromosome behaviour

  2. Homozygous with fragile chromosome

  3. Heterozygote which developed gene mutations

  4. Homozygous with stable chrmosomes


Correct Option: A
Explanation:

Hugo De Vries gave Mutation theory in 1901. He worked on plant Oenothera lamarckiana, commonly known as evening primrose and found several aberrant types. When the plant was self-pollinated and its seeds were allowed to grow, the majority of F$ _1$ plants were similar to the parents, but a few were different plants. Same results were found in F$ _2$ generation. He resulted in that origin of species is through sudden, large changes of traits from another species and these sudden changes are due to Mutation in the gene pool which passes from one generation to another. Later on, it was revealed that most of the variants isolated from Oenothera lamarckiana were due its anomalous chromosome behaviour i.e., chromosome forms multiple rings at meiosis and chromosomal end segments only involves in recombination (low-level crossing over) and plant shows complex heterozygosity i.e., during meiosis maternal and paternal chromosomes are arranged in alternate order. Thus, the correct answer is ‘Complex heterozygote with anomalous chromosome behaviour.’

Choose the correct combination among the following :
(i) Thomas Malthus - Principle of population
(ii) Paul Kammarer - Proteus anguimia
(iii) Hugo de Vries - Oenothera lamarckiana
(iv) Bernard Kettleweli - BIston betularia

  1. i, iv

  2. ii, iv

  3. i, iii

  4. All are correct


Correct Option: D
Explanation:
  1. The work of Thomas Malthus 'Principle of population' inspired Darwin's study of evolution.
    2. Paul Kammarer studied the pattern of inheritance on Proteus anguimia, commonly called 'The midwife toad'.
    3. Hugo de Vries brought forward the idea of mutations after his Workin on Oenothera lamarckiana (evening primose).
    4. Bernard kettleweli studies industrial melanisation on Biston betularia.
    So, the correct option is 'All are correct'.