In a test cross, an individual with an unknown genotype is crossed with a homozy
Practice Questions
Q1
In a test cross, an individual with an unknown genotype is crossed with a homozygous recessive individual. What is the purpose of this cross?
To determine the dominant allele
To determine the recessive allele
To determine the genotype of the unknown
To determine the phenotype of the offspring
Questions & Step-by-Step Solutions
In a test cross, an individual with an unknown genotype is crossed with a homozygous recessive individual. What is the purpose of this cross?
Correct Answer: To determine the genotype of an individual with a dominant phenotype.
Step 1: Understand that a test cross is used to find out the genotype of an individual with a dominant trait.
Step 2: Know that the individual with the unknown genotype can either be homozygous dominant (two dominant alleles) or heterozygous (one dominant and one recessive allele).
Step 3: The individual with a homozygous recessive genotype has two recessive alleles and will always show the recessive phenotype.
Step 4: Cross the individual with the unknown genotype with the homozygous recessive individual.
Step 5: Observe the offspring from this cross.
Step 6: If all offspring show the dominant phenotype, the unknown individual is likely homozygous dominant.
Step 7: If some offspring show the recessive phenotype, the unknown individual is likely heterozygous.
