A tall plant (Tt) is crossed with a tall plant (Tt).What percentage of the offspring will be short?
Assuming that t is a recessive gene for short, it can only happen with tt.
Do you know how to do a Punnett square?
To determine the percentage of short offspring, we first need to understand the genetics involved. In this case, the cross involves a tall plant (Tt) being crossed with another tall plant (Tt).
According to Mendelian inheritance, "T" represents the dominant allele for tallness, while "t" represents the recessive allele for shortness. Since both parent plants are tall, they are both heterozygous (Tt), meaning they carry one dominant and one recessive allele.
When these parent plants are crossed, we can use a Punnett square to determine the possible combinations of alleles in the offspring.
The Punnett square for this cross is as follows:
| T | t |
--------------------
T | TT | Tt |
--------------------
t | Tt | tt |
From the Punnett square above, we can see that there are four possible outcomes: two tall plants (TT and Tt) and two short plants (tt). This means that 50% of the offspring will be short.
Therefore, the percentage of short offspring will be 50%.
To determine the percentage of offspring that will be short, we need to understand the inheritance pattern of height in plants. In this case, the height is determined by a single gene, and we are given that tall is dominant (T) and short is recessive (t).
Given that both parent plants are tall and have the genotype Tt (one dominant allele and one recessive allele), the possible genotypes of the offspring can be determined using a Punnett square.
The Punnett square for this cross would look like this:
T t
T TT Tt
t Tt tt
In the Punnett square, the four boxes represent the possible genotypes of the offspring. We can see that there are two possible genotypes that will result in a tall plant (TT or Tt) and one genotype that will result in a short plant (tt).
Therefore, out of the four possible combinations, one of them (tt) will produce a short plant. This means that 1 out of the 4 offspring is expected to be short.
To calculate the percentage, we divide the number of short plants (1) by the total number of offspring (4) and multiply by 100:
(1 / 4) * 100 = 25%
Therefore, 25% of the offspring are expected to be short plants.