Question

Jenny crosses 2 hybrid pea plants. What is the probability that the offspring will be short? Set-up and complete the punnett square below to solve this problem. (HINT: tt = short, and TT & Tt = tall)

please help

Answer 1

A dominant trait can be described as a trait that masks the effect of recessive trait. A recessive trait can be described as a trait that gets suppressed by a dominant trait. In the above mentioned question, short height is recessive where as tall is dominant.

When a heterozygous tall pea plant is crossed with a homozygous recessive short plant then the offsprings produced will have 50% probability to be heterozygous tall and 50% probability to be short.

Answer 2

1/4 or 0.25

Step-by-step explanation:

This is a monohybrid cross involving a single gene (T) coding for height in the pea plant. According to the hint; genotypes TT and Tt are tall plants while genotype tt is short. Since the heterozygous genotype (Tt) is phenotypically tall. This shows that allele T is the allele for tallness and it is dominant over allele t, which is the allele for shortness.

A hybrid plant is a plant that results from the combination of the alleles of two purebreeding or homozygous plants. It has an heterozygous genotype i.e. different alleles (Tt).

In a cross between two hybrid (Tt), alleles T and t will segregate into gametes according to Mendel's law of segregation. (See attached image). Using a punnet square, four possible offsprings with phenotypic ratio of 3:1 will be produced i.e. 3 tall plants to 1 short plant.

Hence, the probability that a plant will be short (tt) is 1/4 or 0.25.