Answer:
From The School of Biomedical Sciences Wiki. Complementary base pairing is the phenomenon where in DNA guanine always hydrogen bonds to cytosine and adenine always binds to thymine. The bond between guanine and cytosine shares three hydrogen bonds compared to the A-T bond which always shares two hydrogen bonds.
The process that tend to reduceb the variety within a population is called B. Random fertilization.
Atomic number shows the number of protons in the nucleus of an atom.
Atomic weight shows the is an another term for atomic mass, which means <span>It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.</span>
Answer:Valves stop blood flowing backwards
Explanation: Valve are flags of tissue that control the direction of the blood in our heart.,it prevent the backwards flow of blood. valves regulate blood from flowing back into the atria.The right and left atrio-ventricular valves prevent blood from flowing backwards into atria. When the ventricle is full,the valve prevent backwards flow of blood.
Answer:
Dry air is a mechanical mixture of nitrogen, oxygen, argon and several other gases in minor amounts.
Explanation:
