Answer:
The correct answer will be option-D.
Explanation:
Calcium plays an important role in muscle contraction as they are released from the sarcoplasmic reticulum after they receive electric impulse.
Calcium triggers the muscle contraction cycle as these calcium ions bind to the troponin-tropomyosin complex. This binding exposes the myosin-binding site on the actin on which high energy myosin binds and cross-bridge is formed.
This cross-bridge formation causes the contraction of the sarcomere and therefore muscle contracts.
Thus, option-D is the correct answer.
Its hard to believe it but its D.<span />
Answer: Carbon Monoxide is a very harmful and toxic gas which is formed from incomplete combustion of carbon.
Explanation: red blood cells contain haemoglobin ,which are responsible for carrying oxygen into our body system. So oxygen combines with haemagoblin to form oxyhaemogoblin in the red blood cells .
so if a person starts to intake cigarettes which contain high amounts of carbon monoxide ,it reduces oxyhaemogoblin formation because it binds very tightly to the haemogoblin .then carboxyhaemogoblin is formed and its permanent so causing reduction in aerobic respiration, and reduction in oxygen transport and causing damages to heart muscles.
Hope this helps if you need any more explanation feel free to comment in the comment section below !!!
I think the answer is 9.69892×10^7
