One gene on one chromosome is next to another gene that controls a different characteristic. This indicates that genes are <u>strongly linked</u>. When the genes are very close on the same chromosome, they are said to be linked. This means that the alleles, or the gene versions, put together in a chromosome will be more often inherited as a unit than separately.
The first gene contributes to the expression of the second gene. This indicates <u>non-epistatic gene interaction
</u>. We say that gene interaction is non-epistatic when two or more genes interact, but no allele prevents the expression of another, but the first gene contributes to the expression of the second gene.
I do not know the options to the blanks, but I'd say that the answer to the first one is "strongly linked". Think of a chromosome as a phylogenic chart → 2 species that are beside each other are strongly linked, if compared to 2 species 3 spots apart form each other. So, 2 genes that are close to each other are strongly linked.
I do not know the options to the blanks, but I'd say the answer to the second one is epistasis → which is the interaction between two different genes (different means they're not linked alleles).
