Question

9. A purebred tall pea plant is

crossed with a purebred short pea
plant. All of the resulting offspring are
tall. What does this tell you about the
gene controlling pea plant height?
O A. The short version of the gene
wasn't passed from the short parent to
the offspring.
O B. The tall version of the gene is
dominant to the short version of the
gene.
O C. The tall version of the gene
wasn't passed from the tall parent to
the offspring.
O D. The short version of the gene is
dominant to the tall version of the.
gene
-20 -10
-10
0 10 20
o
10

Answer 1

B

Step-by-step explanation:

Answer 2

B) The tall version of the gene is dominant to the short version of the gene.

Step-by-step explanation:

In the question, its given that both the pea plants are purebred for genetically for height. Therefore, we can already pre-determine the combination of letters for each gene, since purebred means that both letters in the combination are the same.

Tall genes: TT

Short genes: tt

Inputting these into a punnet square would give a result of four possible combinations for the offsprings height:

Tt, Tt, Tt, and Tt (doesn't matter which letter is first)

If all the offspring are tall, despite there being a purebred short parent, then we can assume that the tall gene is dominant to the short gene. (Dominant alleles when paired with sub. alleles have the result of the dominant gene actually showing up. In this case, Tt, where the plant is tall due to the T allele regardless of the presence of the short allele t.)

Hope that helped!