yes, cell organelles can be seen with a microscope
Chemical factors: This is due to internal stimuli. Changes in the blood such as decrease in O2, increase in CO2 and decrease in PH cause impulse in the carotid artery which stimulates the respiratory centers in the medulla and cause breathing.
Mechanical factors: also called external stimuli. Compression of the fetal chest during delivery forces small amount of lung fluid out of the lungs. This increase in pressure in the chest draws air into the lungs.
Answer:
They sleep on just one side of their brain at a time
Explanation:
Dolphins are different from fishes that can breathe underwater.
It is necessary for them to get to the surface of the water at intervals to breathe air.
While sleeping, dolphins allows one hemisphere of their brains fall asleep while the other half is fully conscious. This means that If the left brain is sleeping, the right eye stays open and if the right brain is sleeping, the left eye stays open.
This happens so they always know when it's time to surface and breathe and when to escape when there is trouble.
Answer:
C) Network of interconnected membranes.
There are different types of channels for blood flow that transport the blood pumped by the heart. They greatly differ only in the size of their diameters. Arteries are the big ones that are located mostly near the heart. Veins are the next which is where nurses inject you to gather blood. Then, the smallest ones are the capillaries.