What is true about the isolated small tribal populations?

(1) There is a decline in population as boys marry girls only from their own tribe.

(2) Hereditary diseases like colourblindness do not spread in the isolated population.

(3) Wrestlers who develop strong body muscles in their life time pass this character on to their progeny.

(4) There is no change in population size as they have a large gene pool.

Among the human ancestors the brain size was more than 1000 cc in:

1. Homo neanderthalensis

2. Homo erectus

3. Ramapithecus

4. Homo habilis

Industrial melanism as observed in peppered moth proves that :

(1) the true black melanic forms arises by a recurring random mutation. 

(2) The melanic form of the moth has no selective advantage over lighter form in industrial area

(3) The lighter-form of the moth has no selective adavantage either in polluted industrial area or non-polluted area

(4) Melanism is a pollution- generated feature.

Select the correct statement from the following :

1. Darwinian variations are small and directionless

2. fitness is the end result of the ability to adapt and gets selected by nature

3. all mammals except whales and camels have seven cervical vertebrae

4. mutations are random and directional

If the mean and the median pertaining to a certain character of a population are of the

same value, the following is most likely to occur:

1. a normal distribution

2. a bi-modal distribution

3. a T-shaped curve

4. a skewed curve 

Jurassic period of the Mesozoic era is characterized by:

1. gymnosperms are dominant plants and first birds appear

2. radiation of reptiles and origin of mammal-like reptiles

3. dinosaurs become extinct and angiosperms appear

4. flowering plants and first dinosaurs appear

The slow process by which new types of organism arise from existing forms by genetic

variation is called

1. Hybridisation

2. Mutation

3. Evolution

4. Transformation

Which of the following statements is incorrect?

1. Life processes are consequences of reactions that occur in an organism.

2. Living organisms are made of inorganic and organic compounds.

3. Life comes from pre-existing life.

4. Genes are not responsible for the stability or changeability of species.

Study of fossils is called

1. ecology                     

2. angiology

3. exobiology                 

4. none of these

The 'devonian period' is considered to be as

1. age of fishes

2. age of amphibians

3. age of reptiles

4. age of mammals.