Which of the following is important for muscle contraction and nerve impulse transmission?
Ca2+ ions
Mg2+ ions
Both (a) and (b)
Fe2+ ions
Spindle fibre is made up of
tubulin
humulin
intermediate filament
flagelin
A.
tubulin
Tubulin is a cytoskeletal globular protein that polymerizes to form microtubules. These radiate from each end of the cell to form a basket like arrangement which helps in the movement of chromosomes to poles. Microtubules also play an important role in the movement of cilia and flagella.
Intermediate filaments are tough rope- like bundles or protein (keratin, desmin, peripherin, vimentin). They provide mechanical stability to cells and interact with microfilaments and microtubules to form cytoskeleton.
Sigmoid notch is formed by
cavity formed by humerus
cavity formed by radius-ulna
cavity formed by tibia-fibula
cavity formed by femur
An acromian process is characteristically found in the
pelvic girdle of mammals
skull of frog
pectoral girdle of mammals
sperm of mammals
Which of the following pairs is correctly matched?
Cartilaginous joint - Skull bones
Hinge joint - Between vertebrae
Fibrous joint - Between phalanges
Gliding joint - Between zygapophyses of the successive vertebrae
The thin filaments of a muscle fibre are made up of
actin, troponin, tropomyosin
actin, troponin
myosin, troponin
actin, tropomyosin
Which of the following is a transparent tissue
Tendon
Hyaline cartilage
Fibrous cartilage
All of these