Leghaemoglobin is produced in response to
respiration
photosynthesis
fatty acid synthesis
N2 fixation
D.
N2 fixation
Bacteria like Rhizobium and Frankia live free as aerobes in the soil but are unable to fix nitrogen. They develop the ability to fix nitrogen only as a symbiont when they become anaerobic. They are unable to fix nitrogen by themselves. Roots of a legume secrete chemical attractants. Bacteria collect over the root hairs and form an infection thread enclosing the bacteria. Infection thread grows along with multiplication of bacteria. Bacteria stop dividing and form irregular polyhedral structures called bacteroids. In an infected cell, bacteroids occur in groups surrounded by host membrane. The host cell develops a pinkish pigment called leghaemoglobin (Lb). It is oxygen scavenger and is related to blood pigment haemoglobin. It protects nitrogen fixing enzyme nitrogenase from oxygen.
Which of the following is correctly labelled for the given figure
A: PS II; B : PS I; C :e- acceptor, D: LHC
A: LHC; B:e- acceptor; C: PS I; D: PS II
A: PS I; B:PS II; C:e- acceptor; D: LHC
A: e- acceptor; B : LHC; C: PS Il; D: PS I
Microtubule depolymerizing drug such as colchicine is expected to
inhibit spindle formation during mitosis
inhibit cytokinesis
allow mitosis beyond metaphase
induce formation of multiple contractile rings
Which of the following cartoon characters does not share its name with that of a gene
Tintin
Popeye
Asterix
Obelix
Apiculture is associated with which of the following groups of plants
Grapes, maize, potato
Sugarcane, paddy, banana
Guava, sunflower, strawberry
Pineapple, sugarcane, strawberry
Oxygen binding to haemoglobin in blood is
directly proportional to the concentration of CO2 in the medium
inversely proportional to the concentration of CO2 in the medium
directly proportional to the concentration of CO in the medium
independent of the concentration of CO in the medium
During muscular contraction, which of the following events occur
(i) H-zone disappears
(ii) A band widens
(iii) I band reduces in width
(iv) Width of A band is unaffected
(v) M line and Z line come closer
(i), (iii), (iv) and (v)
(i), (i) and (v)
(ii), (iv) and (v)
(i), (ii) and (iii)
Catecholamine in a normal person induces
intense salivation
alertness
decrease in heart beat
excessive urination.
The release of chemical messenger from synaptic vesicles is under the influence of these ion(s).
Cl-
Fe and S2+
Ca2+
Mg2+ and Sr2+