True it gets that through the blood vessels in the umbilical cord
Answer: During the day, photosynthesis is dominant, so there is a net release of oxygen. At night, photosynthesis stops but respiration continues, so there is a net consumption of oxygen.
Explanation:
Answer:
The cell membrane, or in plant cells, the cell wall
Explanation:
In a plant cell the cell wall helps maintain structure, and in animal cells, the cell membrane regulates what goes in and out of the cell and acts as a structure
D
Reason - language disorder resulting from an injury to the brain
Answer:
they are Na+, K+ and Ca2+ ion channels.
Explanation:
Ionotropic acetylcholine receptors are also called nicotinic acetylcholine receptors because beside acetylcholine (Ch) they respond to nicotine. These receptors are primary receptors in muscle for motor nerve-muscle communication that controls muscle contraction.
Two molecules of ACh are required for receptor to open. Since the receptors are linked to ion channels, the channels open. Opening of the channel allows positively charged ions to move across it: sodium enters the cell and potassium exits.
