When levels decrease, the parathyroid releases hormones.
Chlorophyll is a pigment found in the thylakoid membranes of the chloroplasts in the leaves. This is why plants are green. The simple answer is that plants are green because they have green chloroplasts.
Plankton is part of an aquatic ecosystem
Energy loss is demonstrated more clearly on an energy pyramid than on a food web.
The answer is an envelope.
A virus is an infectious agent that can replicate only inside a host cell. When it is outside the cell, it consists of genetic material coated with protein capsid. Some viruses also have an envelope which covers capsid. The function of the envelope is to identify and bind some receptor sites on the host membranes. After fusing with the cell membrane, it allows to capsid and genetic material to enter the cell and infect it.
