Gentics And Evoloution - Practice Test

[#431] Consider the following statements. 1. Hugo de Vries gave the Mutation Theory to explain the mechanism of evolution. 2. Mutations are discontinuous variations and are also called Saltatory Variation. 3. Mutations are the ultimate source of organic variations. Which of the statements given above is/are correct about mutation?

(A) 1, 2 and 3

(B) 2 and 3

(C) 1 and 2

(D) 1 and 3

Correct Answer

(A) 1, 2 and 3

[#432] The advantages of haploids in crop improvement include:

(A) Haploids are useful for induction of mutations and mutation breeding

(B) In hybridisation, the haploids combine the advantages of recombination, segregation and fixation

(C) Use of haploids in the production of homozygous pureline by doubling of chromosomes reduces the total time for developing a new variety from 10 years to 5 to 6 years

(D) All of the above

Correct Answer

(D) All of the above

[#433] Down's syndrome is due to

(A) chromosome number increase in 21 st pair autosome

(B) chromosome number decreases in 21 st pair autosome

(C) chromosome number increases in 18 th pair autosome

(D) chromosome number decreases in 18 th pair autosome

Correct Answer

(A) chromosome number increase in 21 st pair autosome

[#434] Consider the following statements regarding Lamarckism and choose the correct answer: 1. Lamarck believed that change of form of either plants or animals was due to change in environment 2. Lamarck had the idea that organs of plants and animals are developed according to their urgent need 3. Constant use or exercise of organs results in the formation of new organs or increase in size 4. The living beings both plants and animals produce in nature more offsprings than could ordinarily survive

(A) Only 1, 2 and 3 are true

(B) Only 1, 3 and 4 are true

(C) Only 1, 2 and 4 are true

(D) Only 2, 3 and 4 are true

Correct Answer

(A) Only 1, 2 and 3 are true

[#435] The form of micorrhizal association where the fungus lives in the intercellular spaces as well as in the cortical cells is known as

(A) Ectomicorrhiza

(B) Endomicorrhiza

(C) Exomicorrhiza

(D) None of the above

Correct Answer

(B) Endomicorrhiza

Gentics And Evoloution - Study Mode

Correct Answer

[#432] The advantages of haploids in crop improvement include:

Correct Answer

[#433] Down's syndrome is due to

Correct Answer

Correct Answer

[#435] The form of micorrhizal association where the fungus lives in the intercellular spaces as well as in the cortical cells is known as

Correct Answer