Please help!! I need an answer to this question from a test

In sexual reproducing animals once fertilization of the egg takes place, the exists as a single cell until cell division begins. a) egg b) larva c) sperm d) zygote

Why did mendel use pea plants in his experiments? a. they have no alleles. b. they are haploid organisms. c. they reproduce quickly. d. they are all male.

Part a - which gene to compare? in this exercise, you will use the cytochrome c oxidase i (coi) gene to investigate relationships among salmon species. (this gene encodes a protein that functions in the mitochondrial electron transport chain.) you will compare the coi gene sequences from your salmon test samples to the standard sequences for each salmon species. in order for the coi gene to be useful for distinguishing among the different salmon species, which three statements must be true?