The answer is B: no
Hope this helps!
The motor neuron carries the nerve impulse.
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The nerve impulse reaches the neuromuscular junction.
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Calcium ions release into the myofibrils.
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Myosin and actin protein filaments attach to each other.
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Myosin filaments pull on the actin filaments.
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The sarcomere shortens.
The neurotransmitter (ACh) from motor neurons signals a muscle fiber to depolarize. The depolarization (Na+) will trigger Ca++ release and will initiate contraction by binding to troponin. Myosin pulls the actin strands. ATP sustains the contraction.
Answer:
B. the input zone of a nerve cell.
Explanation:
Dendrites are the small extensions that come out of the soma or cell body of a neuron. The function of dendrites is to receive the nerve signals or information from the axons of the presynaptic neurons and carry them towards the cell body or soma. In a synapse, the signals from the axons of the presynaptic neurons are revived by dendrites of postsynaptic neurons. The plasma membrane of dendrites have receptors to which the chemical messengers from other cells bind. In this way, dendrites serve as input zone of a nerve cell.
The answer should be C, It diffuses from the alveoli into the blood.
Alveoli, also called the air sac, is the place where the oxygen we breathed in is exchanged with carbon dioxide that our body produces. Oxygen is passed into the blood in the capillaries through the process of diffusion, while carbon dioxide is diffused from the blood back to the alveoli, so that we can exhale the carbon dioxide after that.
Both a and b are not right because when we breathe in, the oxygen travels from the trachea to the bronchi, to the bronchiole, and to the alveoli, instead of directly into blood vessels like arteries, capillaries, or veins. d is also not right because the direction is wrong.
Therefore, your answer should be C.
