Genetics and Evolution - short answer questions

 

Evolution (NEET Syllabus): Origin of life; Evolution of Life Forms; Universe; Origin of Universe; Biological Evolution and Evidences for Biological Evolution from Paleontology, Comparative Anatomy, Embryology and Molecular Evidence; Darwin’s Contribution, Modern Synthetic theory of Evolution; Mechanism of Evolution-Variation (Mutation and Recombination) and Natural Selection with examples, types of Natural Selection; Gene Flow and Genetic Drift; Lamarckism; Darwinism; Mutation Theory of Hugo De Vries; Hardy-Weinberg’s Principle; Adaptive Radiation; Human Evolution.  

EVOLUTION (Genetics and Evolution)

Theoretical Questions - TQ 1 (Q. No. 1-6)

Very Short Answer Type Questions

Question.1: Define fossils.
Question.2: Write name of two Vestigial organ of human.
Question.3: Define Genetic Drift.
                   Or,
The random changes in the allele frequency occurring by chance alone are genetic drift.

Short Answer Type Questions

Question.4: What is meant by analogous organ? Taking a suitable example, explain how they support the theory of organic evolution.
Question.5: What is speciation?
Question.6: Explain Disruptive Nature of selection?

Answer 1: Fossils are preserved remains, traces or prints of organism that lived in past.

Answer 2:
(i) Vermiform appendix, (ii) Tail vertebrae.

Answer 3:
Genetic Drift: (Sewall Wright effect)
"Drift is a binomial sampling errors of the gene pool." Sampling errors (error in gene pool of next generation mean gametic error) by chance often lead to the elimination of certain alleles and fixation of other and it ultimately cause the loss of genetic diversity.
                 Or,
The random changes in the allele frequency occurring by chance alone are called genetic drift.

Answer 4: The organs which have different developmental origin and structural design but perform similar functions are called analogous organs. The wings of birds and insects are analogous organs indicating that they have different ancestors but show a convergent evolution.

Answer 5:
Speciation is formation of one or more new species from pre-existing species. It can be of two types:

Allopatric speciation
When a population formerly continuous in a range, splits into two or more geographically isolated population and form new species. Eg. Darwin finches, Marsupial radiation.

Sympatric speciation
When a population reproductively isolated in midst of its parent population and form new species. Sympatric speciation is the formation of a species within a single population without geographical isolation. Ex. Quated example of sympatric speciation comes from polyploidy (when chromosome fails to segregate at meiosis or replicate without undergoing mitosis).

Answer 6:
Disruptive Nature of Selection

Natural selection that favours the extremes of a phenotype in a population. It often operates when an environmental factor shows distinct variations, for example high temperatures in summer and low temperatures in winter with no intermediate forms. In this case the population will be variously adapted to withstand both high and low temperatures.

Genetics and Evolution - More Practice and Sample Questions with Answers 
<<Prev                                                                   Next>>

 Recent Posts
BIOLOGY
CHEMISTRY
PHYSICS

No comments:
Write comments