41.

The maintenance of internal favourable conditions by a self-regulated mechanisms in spite of the fact that there are changes in environment, is known as

• entropy

• enthalpy

• homeostasis

• steady state

The linkage map of X-chromosome of fruit-fly has 66 units, with yellow body gene (y) at one end and bobbed hair (b) gene at the other end. The recombination frequency between these two genes (y and b) should be

• $\le$50%

• 100%

• 66%

• > 50%

In Drosophila, the sex is determined by

• the ratio of pairs of X-chromosomes to the pairs of autosomes

• whether the egg is fertilised or develops parthenogenetically

• the ratio of number of X- chromosomes to the set of autosomes

• X and Y-chromosomes

Which one of the following conditions though harmful in itself, is also a potential saviour from a mosquito borne infectious disease?

• Pernicious anaemia

• Leukaemia

• Thalassaemia

• Sickle cell anaemia

Short-lived immunity acquired from mother to foetus across placenta or through mother's milk to the infant is categorised as

• cellular immunity

• innate non-specific immunity

• active immunity

• passive immunity

Bartholin's glands are situated

• on either side of vagina in humans

• on either side ofvas deferens in humans

• on the sides of the head of some amphibians

• at the reduced tail end of birds

Down's syndrome is caused by an extra copy of chromosome number 21. What percentage of a normal father would be affected by this disorder?

• 50%

• 25%

• 100%

• 75%

Genetic map is one that

• shows the stages during the cell division

• shows the distribution of various species in a region

• establishes sites of the genes on a chromosome

• establishes the various stages in gene evolution

Pollorum disease of poultry is caused by

• Mycobacterium

• Salmonella

• Clostridium

• Haemophilus

Minamata disease is pollution related disease. It result from

• oil spills in sea

• DDT pollution

• release of industrial waste containing mercury in fishing water

• accumulation of arsenic