Two amino acids form a peptide bond together as these are just proteins.
Nervous system is the body system that is involved in coordinating and controlling body movements
The statement which best explains why carbon is present in so many kinds of molecules is because <u>it can form four covalent bonds.
<em /></u>It isn't rare on Earth, so A is incorrect. It has valence electrons, so C is incorrect. It cannot become an ion, so D is incorrect.<u>
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Answer:
There are many ways.
Explanation:
Humans have a combined respiratory and circulatory system, whereas insects do not. In humans, the air is brought in through the mouth/nose, through the windpipe, and into the lungs, the oxygen is absorbed into the bloodstream where it can be transported to muscles and organs. However, insects take in air through tiny holes in their thorax and abdomen. These are called spiracles. The oxygen is stored in many dorsal air sacs to be used. Then carbon dioxide is expelled through the spiracles.
