Variations during mutations of meiotic recombinations are:

1. random and directionless

2. random and directional

3. small and directional

4. random, small and directional

Subtopic:  Sources of Variation: 1 | Sources of Variation: 2 |
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Darwin's in his natural selection Theory did not believe in any role of which one of the following in organic evolution?  
1. Parasites and predators as natural enemies
2. Survival of the fittest
3. Struggle for existence
4. Discontinuous variations 
 

Subtopic:  Darwin's Theory |
 66%
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Convergent evolution is illustrated by   
1. rat and dog.
2. bacterium and protozoan
3. starfish and cuttlefish
4. dogfish and whale 

Subtopic:  Concept of Organic Evolution: Evidence |
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Industrial melanism is an example of        
1. drug resistance
2. darkening of skin due to smoke from industries
3. protective resemblance with the surroundings
4. defensive adaptation of skin against ultraviolet radiations.

Subtopic:  Concept of Organic Evolution: Evidence |
 72%
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Which one of the following correctly describes the homologous structures?
1. Organs with anatomical similarities, but performing different functions.
2, Organs with anatomical dissimilarities, but performing same functions.
3. Organs that have no functions now, but had an important function in ancestors.
4. Organs appearing only in embryonic stage and disappearing later in the adult.
 

Subtopic:  Concept of Organic Evolution: Evidence |
 91%
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Which one of the following sequences was proposed by Darwin and Wallace for organic evolution?   

1. Overproduction, variations, constancy of population size, natural selection
2. Variations, constancy of population size, overproduction, natural selection
3. Overproduction, constancy of population size, variations, natural selections
4. Variations, natural selection, overproduction, constancy of population size
Subtopic:  Darwin's Theory | Summary of Darwin's Theory | Concept of Organic Evolution: Evidence |
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If a random mating population is in equilibrium, which of the following brings about a change in gene frequency in a non-directional manner? 
1. Mutations
2. Random drift
3. Selection
4. Migration 

Subtopic:  Sources of Variation |

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Random genetic drift in a population probably results from  
1. highly genetically variable individuals. 
2. inbreeding within this population
3. constant low mutation rate
4. large population size 

Subtopic:  Sources of Variation |

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In recent years, DNA sequences (nucleotide sequence) of mtDNA and Y chromosomes were considered for the study of human evolution, because             
1. they are small, and therefore, easy to study
2. they are uniparental in origin and do not take part in recombination
3. their structure is known in greater detail.
4. they can be studied from the samples of fossil remains. 

Subtopic:  Modern Theory of Evolution |
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According to Oparin, which one of the following was not present in the primitive atmosphere of the earth?  

1.Oxygen2.Hydrogen
3.Water vapour4.Methane 

Subtopic:  Examples of Chemical Evolution |
 93%
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