Sickle cell anaemia has not been eliminated from the African population because
it is controlled by recessive genes
it is not a fatal disease
it provides immunity against malaria
it provides immunity against malaria
C.
it provides immunity against malaria
Sickle cell anaemia (in which RBCs become sickle shaped and stiff) is a genetic disorder that is autosomal and linked to a recessive allele. It has not been eliminated from the african population because it provides immunity against malaria. People who are heterozygous for sickle allele are much less susceptible for falciparum malaria which is one of the main causes of illness and death in them. Thus, the sickle cell allele is maintained at high levels in population where falciparum malaria is common.
Limit of BOD prescribed by Central Pollution Control Board for the discharge of industrial and municipal waste water into natural surface water, is:
< 3.0 ppm
< 10 ppm
< 100 ppm
< 100 ppm
Withdrawal of which of the following hormones is the immediate cause of menstruation?
Eastrogens
FSH
FSH-RH
FSH-RH
The arrangement of the nuclei in a normal embryo sac in the dicot plants is
2+4+2
3+2+3
2+3+3
2+3+3
An enzyme that can stimulate germination of barley seeds is
α-amylase
lipase
protease
protease
In a cereal grain the single cotyledon of embryo is represented by
coleorhiza
scutellum
prophyll
prophyll
Triticale, the first man-made cereal crop, has been obtained by crossing wheat with
rye
pearl millet
sugarcane
sugarcane
In order to obtain virus-free plants through tissue culture the best method is
protoplast culture
embryo rescue
anther culture
anther culture
HIV that causes AIDS, first starts destroying
B-lymphocytes
leucocytes
thrombocytes
thrombocytes
Both sickle cell anaemia and Huntington's chorea are
bacteria-related diseases
congenital disorders
pollutant-induced disorders
pollutant-induced disorders
