If there are only two alleles for a gene in a population one dominant and one recessive what possible genotype could an organism have for this gene?

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Rotenone is an insecticide that is toxic

How is the national wildlife refuge system similar to the pacific region coastal program? a. both programs are concerned with providing habitats for wildlife b. both programs are primarily concerned with preserving fish species c. both programs have set aside 150 million acres of land d. both programs are under the u.s. fish and wildlife service