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What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

Awater molecule is polar because there is an uneven distribution of these between the oxygen and hydrogen atoms.

Why do mutations in genes affect traits? o a. genes determine what type of mutagens an organism has. o b. genes produce proteins that cause traits. o c. genes affect how many chromosomes an organism has o d. genes code for carbohydrates that influence traits.