Tag: zoology

Quizzes (289) Questions (5869)

Questions Related to zoology

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

Gene frequency in a population remains stable, unless and until there is ___________.

  1. Random drift

  2. Random mating

  3. Selection

  4. Mutation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • In biology, a mutation is the alteration of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA.
  •  Mutations result from errors during DNA replication or other types of damage to DNA such as may be caused by exposure to radiation or carcinogens.
  • Hence, gene frequency in a population remains stable, unless and until there is a mutation. 
  • So, the correct answer is 'Mutation'.
Multiple choice zoology the paths traversed by life mutational theory of evolution theories of evolution other theories of evolution

The theory of mutation was propagated by

  1. Hugo De Vries

  2. Charles Darwin

  3. Neo Darwinism

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

Mutations are sudden changes in the characteristics of organisms due to chemical changes in the genetic material. The theory of mutation was proposed by Hugo De Vries. Charles Darwin gave the theory of natural selection and Neo-Darwinism is an advanced version of darwins theory.

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

Who coined the term 'mutation'?

  1. Morgan

  2. Darwin

  3. de Vries

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

The term mutation was introduced by Hugo de Vries, while working on evening primrose. He observed aberrent types in $F _1$ generation of two pure breeding varieties. The sudden appearance of new characters was termed as mutation, which he defined as sudden, discontinuous, inheritable changes in genetic material. 

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

The concept of sudden genetic change, which breeds true in an organism is visualized as

  1. Natural selection

  2. Inheritance of acquired characters

  3. Mutation

  4. Independent assortment
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The concept of sudden genetic change, which breeds true in an organism is visualized as a mutation. Any sudden or spontaneous change in character which is inheritable is known as mutation. It is defined as the changing of the structure of a gene, resulting in a variant form which may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes.

So, the correct answer is option C.

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

After observing the variations Hugo De Vries first of all described the mutation in

  1. Oenothera lamarckiana

  2. Neurospora crassa

  3. Pisum sativum

  4. Drosophila melanogaster
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hugo de Vries studied inheritance of flower colour in Oenothera lamarckiana (evening primrose) and proposed mutation theory that says that mutations are sudden, random, and inheritable and discontinuous variations which serve as raw material for evolution. 

George Beadle and Edward Tatum gave molecular definition of a gene while working on nutritional mutants in Neurospora crassa and proposed the one gene–one enzyme hypothesis.
Mendel conducted hybridization experiments on garden pea plant, Pisum sativum and proposed “Laws of inheritance” but did not observe any mutations.
Morgan and Muller identified radioactive nature of X-rays to induce point mutations while working on sex linked inheritance in Drosophila. 
So, the correct answer is option A.

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

Which one of the following scientist's name is correctly matched with the theory put forth by him?

  1. De Vries - Natural selection

  2. Mendel - Theory of Pangenesis

  3. Weismann - Theory of continuity of Germplasm

  4. Pasteur - Inheritance of acquired characters
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

a) Theory of evolution was given by De Vries in 1901 which states that evolution is a process where new species are formed due to mutations that functions as a raw material for evolution.

b) Mendel experimented on pea plant for seven years (1856-1863) and proposed the law of inheritance in living organisms. 
c) Theory of continuity of germplasm was proposed by Wiesmann in 1884 but published in 1893 and states that heritable information is transmitted by germ cells only to gonads but not by somatic cells.
d) The germ theory of disease was proposed by Pasteur in late 1850s.
So, the correct answer is 'Weismann - 'Theory of continuity of Germplasm'.

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

In nature, the occurrence of mutations are

  1. Mostly harmful

  2. Mostly useful

  3. Mostly neutral

  4. Mostly neutral or harmful
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Example for harmful effect of mutation: Oncogenes are harmful mutations can cause cells to become malignant and can ultimately lead to cancer. Mutations are mostly harmful and sometimes neutral (silent mutations)

So, the correct answer is 'Mostly neutral or harmful'

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

The ultimate source of organic evolution is

  1. Selection

  2. Sexual reproduction

  3. Hormonal action

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

According to Dobzhansky, mutations, which help organisms in its survival, in the changing environment are accumulated in its genetic composition by natural selection. Mutations are now considered as the ultimate source of organic evolution. By mutations, some old genes can be replaced by new genes in a population to develop changes and thus, mutations play important part in the process of organic evolution.
Thus, the correct answer is option (D), 'Mutation'.

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

Hugo de Vries discarded the principle of

  1. Darwin

  2. Lamarck

  3. Haeckel

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

Hugo de Vries gave mutation theory and felt the importance of chance events i.e., mutations during evolution. This was against Darwinian view of evolution as a slow directional process. Mutations are random chance events and result in sudden evolution of characters in a single or few generations.