In a certain species, the allele for tall plants (T) is dominant over the allele
Practice Questions
Q1
In a certain species, the allele for tall plants (T) is dominant over the allele for short plants (t). If two heterozygous tall plants (Tt) are crossed, what is the expected phenotypic ratio of the offspring?
1:2:1
3:1
9:3:3:1
1:1
Questions & Step-by-Step Solutions
In a certain species, the allele for tall plants (T) is dominant over the allele for short plants (t). If two heterozygous tall plants (Tt) are crossed, what is the expected phenotypic ratio of the offspring?
Step 1: Identify the alleles. Tall plants have the allele T (dominant) and short plants have the allele t (recessive).
Step 2: Determine the genotypes of the parent plants. Both parent plants are heterozygous tall, which means they have the genotype Tt.
Step 3: Set up a Punnett square to visualize the possible combinations of alleles from the two Tt parents.
Step 4: Fill in the Punnett square. The possible combinations are: TT, Tt, Tt, and tt.
Step 5: Count the phenotypes. The combinations TT and Tt result in tall plants, while tt results in short plants.
Step 6: Calculate the ratio of tall to short plants. There are 3 tall plants (TT and Tt) and 1 short plant (tt).
Step 7: Write the expected phenotypic ratio. The ratio of tall to short plants is 3:1.
