YY and Yy would result in a plant with yellow seeds. This is because Y is dominant and yellow seeds would show with a dominant homozygous and a heterozygous. It can't be yy because that would be homozygous recessive
They say how an enzyme perfectly fits into its substrate is alike a "lock and key".
Only one specific enzyme can fit a specific substrate.
The answer is true as phenotype involves of having to see the organisms character and their morphological features, by this, it is trying to apply to both of the physical and psychological characteristics, making the sentence above as true.
