1. possible gamete genotypes produced by an individual of genotype ppdd are
a) pp and dd
b) all ppdd
c) pd and pd
d) pd, pd, pd, and pd

D) PD, Pd, pD, and pd

Explanation:

You need to draw a Punnet chart and put P (represent a dominant character) and p (represent a recesive character) abobe. Then D (represent a dominant character diferent than P) and d (represent a recesive character different tan d).

When you do the cross over, you will end with four possibles gamete genotypes and those are PD, Pd, pD and pd.

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.