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
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%
A.
50%
Down's syndrome is the result of trisomy in which chromosome number 21st contains an extra copy of chromosome (2A + 1). Affected mother will produce 50% normal egg cells and rest 50% eggs are of abnormal type.
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
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