try A or b, they both have a membrane i belive
The hormone ADH operates by negative feedback mechanism in that when the body's tissues lack water, it causes the nephrons to retain water to prevent the body's tissues drying out.
The nitrogen in the air cannot be used by producers and consumers. It must be fixed or converted by bacteria in the ground into a useable form for plants called nitrates. Some plants called legumes (beans and clover) actually have bacteria in their roots.
Preganglionic axons synapse at the sympathetic chain ganglia with a postganglionic neuron. The postganglionic neuron then leaves the sympathetic chain ganglia through a gray ramus communicans (unmyelinated axons) and reenters the spinal nerve and travels to the skin and blood vessels throughout the body.
a) A warm air mass rises above a cold air mass during a warm front, but two cold air masses surround a warm air mass during an occluded front.
