- (i) The infective stage of Plasmodium which Anopheles
mosquito takes in, along with the blood meal, from an
infected human is gametocyte.
(ii) Malaria is characterised by fever at intervals, sudden
acute chillness (cold rigor stage) accompanied by
shivering followed by rise in temperature. Malaria fever
occurs when schizonts in red blood corpuscles burst and
set free their contained merozoites and malarial pigment
(haemozoin) in the blood plasma. Bursting of schizonts
tends to be synchronous as they all burst at the same
time. Haemozoin is said to be toxic and so induces high
fever and shivering.
(iii)
- According to the mode of breeding there are two types
of fish breeding, natural breeding and induced breeding.
Natural breeding (Bundh breeding) - Breeding occurs in
natural bundhs which are special types of ponds where
natural water resource conditions are managed for the
breeding of culturable fish.
Induced breeding - It is the artificial method of fertilising
ova from the females and the sperms from males which
are taken out by artificial means. Stimulation of ovulation
by administering gonadotropins, and other hormones is
an important step in induced breeding.
- (i) The proinsulin has A, B and C polypeptide strands. It
is non functional. The mature insulin has only A and B
polypeptide strands. It is functional.
(ii) From the human cell, DNA containing insulin gene is
isolated. The two DNA sequences corresponding to A
and B chains of human insulin is introduced into the
plasmids of E. coli to produce insulin chains A and B.
The extracted chains A and B are combined by creating
disulphide bonds to form human insulin (humulin).
(iii) The insulin prepared by rDNA technology does not
produce sensitive allergic reactions and immunological
reactions whereas those used earlier, produced allergic
reactions and other complications to the foreign protein
as earlier insulin was extracted from pancreas of
slaughtered cattle and pigs.- (i) Tourists visiting high altitude areas such as Rohtang
Pass or Mansarovar, experience altitude sickness. Its
symptoms include nausea, fatigue and heart palpitations.
This is because in the low atmospheric pressure of high
altitudes, the body does not get enough oxygen. But,
gradually we get acclimatized and stop experiencing
altitude sickness. The body compensates low oxygen
availability by increasing red blood cell production,
decreasing the binding affinity of haemoglobin and by
increasing breathing rate. Thus, the visitors are advised
to resume their normal active life involving heavy work
only after few days, because for doing heavy tasks, our
body needs energy, and this energy is obtained by the
oxidation of glucose in the presence of oxygen. This
oxygen is carried to the cells by haemoglobin present in
RBCs. As oxygen is the limiting factor in high altitudes,
more carrier molecules i.e., haemoglobin molecules are
needed to provide sufficient amount of oxygen to cells.
Thus, increased RBC production, that starts in a few days
after reaching altitudes, prepares the tourists to lead a
normal active life.
(ii) According to Bergman’s rule, temperature affects the
absolute size of an animal and the relative proportion
of various body parts. Birds and mammals attain greater
body size in cold regions than in warm areas. Thus,
smaller animals are rarely found in polar regions. It can
be explained that as small animals have a larger surface
area relative to their volume, they tend to loose body heat
very fast when it is cold outside. Due to higher heat loss,