Evolution

Random genetic drift in a population probably results from

1. Constant low mutation rate
2. Interbreeding within this population
3. Large population size
4. Highly genetically variable individuals

Industrial melanism is an example of :-

1. Darkening of skin due to smoke from industries
2. Defensive adaptation of skin against ultraviolet radiations
3. Drug resistance
4. Protective resemblance with the surroundings

In a random mating population in equilibrium, which of the following brings about a change in gene frequency in a non-directional manner :-

1. Selection
2. Random drift
3. Mutations
4. Migration

Darwin in his 'Natural Selection Theory' did not believe in any role of which one of the following in organic evolution ?

1. Survival of the fittest
2. Parasites and predators as natural enemies
3. Discontinuous variations
4. Struggle for existence

Which one of the following describes correctly the homologous structures ?

1. Organs with anatomical dissimilarities but performing same function
2. Organs that have no function now, but had an important function in ancestors
3. Organs with anatomical similarities, but performing different functions
4. Organs appearing only in embryonic stage and disappearing later in the adult

In recent years, DNA sequences (nucleotide sequence) of mt-DNA and Y chromosomes were considered for the study of human evolution, because :-

1. They are uniparental in origin and do not take part in recombination
2. They can be studied from the samples of fossil remains
3. Their structure is known in greater detail
4. They are small, and therefore, easy to study

Some bacteria are able to grow in streptomycin containing medium due to

1. natural selection
2. induced mutation
3. reproductive isolation
4. genetic drift.

Which of the following is important for speciation ?

1. Behavioural isolation
2. Seasonal isolation
3. Tropical isolation
4. Reproductive isolation

Which of the following are homologous organs ?

1. Wings of birds & Pectoral fins of fish
2. Wings of bat & Butterfly
3. Legs of frog & Cockroach
4. Wings of birds & Locust

Genetic drift operates in : -

1. Slow reproductive population
2. Small isolated population
3. Large isolated population
4. Fast reproductive population