In which one of the following pairs the two items mean one and the same thing
Malleus - anvil
SA node - pacemaker
Leucocytes - lymphocytes
Haemophilia - blood cancer
B.
SA node - pacemaker
The sinoatrial node (SA node), also known as sinus node, is a group of cells located in the wall of the right atrium of the heart. These cells have the ability to spontaneously produce an electrical impulse, that travels through the heart via the electrical conduction system causing it to contract. In a healthy heart, the SA node continuously produces action potential, setting the rhythm of the heart and so is known as the heart's natural pacemaker.
Unidirectional transmission of a nerve impulse through nerve fibre is due to the fact that
nerve fibre is insulated by a medullary sheath
sodium pump starts operating only at the cyton and then continues into the nerve fibre
neurotransmitters are released by dendrites and not by axon endings
neurotransmitters are released by the axon endings and not by dendrites.
In a plant organ which is covered by periderm and in which the stomata are absent, some gaseous exchange still takes place through
aerenchyma
trichornes
pneumatophores
lenticels.
Which one feature is common to leech, cockroach and scorpion
Nephridia
Cephalisation
Ventral nerve cord
Antenna
The total number of nitrogenous bases in human genome is estimated to be about
3.5 million
35 thousand
35 million
3.1 billion.
The sugarcane plant has
dumb-bell shaped guard cells
pentamerous flowers
reticulate venation
capsular fruits.
The bacteria Pseudomonas aeruginosa is useful because of its ability to
transfer genes from one plant to another
decompose a variety of organic compounds
fix atmospheric nitrogen in the soil
produce a wide variety of antibiotics
Which one of the following categories of organisms do not evolve oxygen during photosynthesis
Red algae
Photosynthetic bacteria
C4 plants with Kranz anatomy
Blue green algae
Pruning of plants promotes branching because the axillary buds get sensitized to
ethylene
gibberellin
cytokinin
indole acetic acid.
