Answer:
4, 3 5, 1, 2.
Explanation:
The events of muscle contraction begins from the presynaptic neuron, which cause the influx of Ca+, and the release of acetycholine neurotransmitter into the synaptic cleft.
The Ach, binds with the receptors in the sarcolemma, leading to opening of Ligand gated Na+ channels. Therefore Na+diffuses in, causing depolarization, and propagation of action potential along the sarcolemma spreading to the T-tubules.
This is followed by opening of Calcium channels leading exist of Ca+ from the sarcoplasmic reticulum.
The Calcium binds with the troponin, and Tropomysoin exposed the myosin binding sites on the actin filament.Thus cross-bridge is formed by the myosin head with thin filaments which shortened the sarcomere, leading to contraction of muscle fibres.
Answer:
Two types of relationships between variables are direct and inverse variation. ... As one variable increases, the other also increases, and as one decreases, the other also decreases. In contrast, inverse variation suggests that variables change in opposite directions. As one increases, the other decreases and vice versa.
Explanation:
Microtubule roots and fibres
Answer
Cellulose, lignin and suberin are the chemicals that provide rigidity to cell wall.
Explanation
In plant two type of growth occurs, primary and secondary growth. in primary growth when new cells are formed they are bounded by primary wall whose composition in mainly of cellulose. in secondary growth accumulation of lignin in secondary wall, suberin in cork cell wall and lignin in xylem cell wall occurs which provide rigidity.