If brown hair is dominant and red hair is recessive, what are the possible genotypes for Sally is she has brown hair?

the answer is BB, Bb

Explanation:

If brown hair is dominant you need to consider the fact that it cant be bb otherwise she would have red hair because lowercase genotypes mean recessive. this eliminates the first and third answer leaving you with the second and fourth answer and we can eliminate the second answer because it says "what are the possible genotypes" meaning we need to list all the possible answers which leaves you with the fourth option.

where is the diagram?

if you insert the diagram ill be able to you

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.