Someone please help me i’m so confused it don’t make sense

What should be the strand of complementary dna produced by the strand of dna shown below cgt ata

Which statement describes compounds a. compounds are made of one type of atom. b. compounds cannot be represented by models. c. compounds are represented by chemical formulas. d. compounds cannot be broken down into simpler forms.

Natural selection changes allele frequencies because some survive and reproduce more successfully than others.