Question

The technique used to find out if a dominant phenotype is homozygous or heterozygous is called:

• A. Back cross
• B. Test cross
• C. Punnett tool
• D. Monohybrid cross

Answer 1

The correct option is B

Test cross

Test cross is a tool first described by Gregor Mendel to determine an unknown genotype. It is a cross between an organism with a homozygous recessive genotype and an organism with an unknown genotype. That is, a test cross can help determine whether a dominant phenotype is homozygous or heterozygous for a specific allele. If the test cross results in any recessive offspring, then the parent organism is heterozygous for the allele in question. If the test cross results in only phenotypically dominant offsprings, then the parent organism is homozygous dominant for the allele in question.
The cross between individual with any one of the parents is called back cross. The back cross is done in order to achieve offspring with a genetic identity which is closer to that of the parent.
Punnett tool shows the genotypes two individuals can produce when crossed.
A monohybrid cross is a mating between two individuals with different alleles at one genetic locus of interest.