The H-zone in the skeletal muscle fibre is due to
the absence of myofibrils in the central portion of A-band
the central gap between myosin filaments in the A-band
the central gap between actin filaments extending through myosin filaments in the A-band
extension of myosin filaments in the central portion of the A-band
C.
the central gap between actin filaments extending through myosin filaments in the A-band
H-zone in skeletal muscle is the central gap between actin filaments extending through myosin filaments in the A-band. Alternate arrangement of dark and light bands gives the striated appearance to a skeletal muscle. At the centre of A-band, a comparatively less dark zone called H-zone is present. In the centre of H-zone, M-line is present, formed by the threats that connect the myofilaments.
Which of the following are correctly matched with respect to their taxonomic classification?
Flying fish, cuttlefish, silverfish - Pisces
Centipede, millipede, spider, scorpion - Insecta
House fly, butterfly, tse-tse fly, silverfish - Insecta
Spiny anteater, sea urchin, sea cucumber - Echinodermata
Which of the following is not correctly matched for the organism and its cell wall degrading enzyme?
Bacteria - Lysozyme
Plant cells - Cellulase
Algae - Methylase
Fungi - Chitinase
Which group of animals belong to the same phylum?
Malarial parasite, Amoeba, mosquito
Earthworm, pinworm, tapeworm
Prawn, scorpion, Locusta
Sponge, sea anemone, starfish
What external changes are visible after the last moult of a cockroach nymph?
Mandibles become harder
Anal cerci develop
Both fore wings and hind wings develop
Labium develops
Which of the following are likely to be present in deep sea water?
Archaebacteria
Eubacteria
Blue-green algae
Saprophytic fungi
Which of the metabolites is common to respiration mediated breakdown of fats, carbohydrates and proteins?
Glucose-6-phosphate
Fructose 1, 6-bisphosphate
Pyruvic acid
Acetyl Co-A