Now that you have identified the components of dna, can you describe how these components bind together to form a dna molecule

DNA has three components a phosphate group, a sugar deoxyribose and 4 nitogenous bases.

DNA has two important bonds that make up the DNA which are phosphodiester bond and hydrogen bonds.

Explanation:

The phosphate of the one nucleotide in DNA bonds with the 5 sugar (5' carbon) of the next nucleotide forming the PHOSPHODIESTER BOND which is a strong covalent bond.

The other bond in DNA is the hydrogen bonds which are among the nitrogenous bases.

There are four bases adenine,guanine,cytosine,thyamine

These bases are held together by strong hydrogen bonds.

Adenine and thyamine have two hydrogen bonds between them and cytosine and guanine have three hydrogen bonds between them.

These hydrogen bonds keeps the DNA helix in place.

the right option is; decreased genetic variation  

decreased genetic variation describes the effect of this environmental change.

genetic variation is the naturally occurring genetic diversities or differences between organisms of the same species in a population. genetic variation allows the survival and adaptability of a species when they encounter changing environmental conditions. when an endangered species reduces, it loses genetic variation which may not be restored even if the species rebound and will only be recovered through the gradual collection of mutations over many years.