Question

TT × tt is
A. Test cross
B. Back cross
C. Monohybrid cross
D. Reciprocal cross

Answer 1

Hint:
Mendel is the father of genetics. He proposed three laws. These laws came into existence after an experiment on peas was done. Mendel crossed two homozygous individuals which resulted in heterozygous offspring.

Complete answer:
A monohybrid cross is a hybrid of two individuals having homozygous genotype which results in the opposite phenotype.
In this TT× tt cross, the dominant trait is the one that appears in the phenotype, so all the offspring will be tall. All four offspring will have a Tt genotype.
A cross between a homozygous tall plant (TT) with the homozygous dwarf plant(tt) is called a monohybrid cross. In the F1 generation, a heterozygous tall plant (Tt) is formed. When it is allowed for self-pollination, 3 tall plants and 1 dwarf plant are formed, in the F2 generation.

Hence, TT × tt is a monohybrid cross. So Option (C) is correct.

Additional information-
The backcross is the mating of a hybrid organism with one of its parents or with an organism genetically similar to the parent.
In the case of animal breeding, a backcross is often called a top cross.
In a test cross, the breeding of an individual with a recessive individual is done to determine the zygosity of the former by analyzing offspring phenotypes. It is used to distinguish between the genotype of an individual which is phenotypically dominant.
A reciprocal cross is done to determine the role of parental sex on a given inheritance pattern.
A monohybrid cross involves the organisms that are heterozygous for only one character.

Note: A monohybrid cross can be done by using the Punnett Square (P-Square) method. This experiment was first done by Mendel. He experimented on peas to prove the Law of Dominance, i.e. when the factors are mixed, the Dominant allele expresses. A phenotype is the physical characteristics of a particular trait.