Question

In a homozygous pea plant, axial flowers (A) are dominant over terminal flowers (a).
Draw a Punnett square board to show the gametes and offsprings when both the parent plant are heterozygous for axial flowers.

Answer 1

Hint:Genotypes of a given plant can be studied through Punnett square giving the probability of an offspring having a particular genotype. Here (A) denotes the dominant trait in the plant and (a) denotes recessive trait in the plant means A will show the law of dominance over a trait allele described by Mendel laws.

Complete step by step answer: 1. When the parent plants are heterozygous means both have dissimilar alleles pair of the same trait
2. Both the allele will not be dominant or recessive
3. By this Aa will be the heterozygous parent genotype
4. When these will undergo the recombination pairing pair of alleles will distort themselves and act as the independent assortment which will assign a specific independent trait on inheriting
5. All the four independent alleles will form the gametes as follows: A, a, A, a
6. On recombination possible offspring with genotype AA, Aa, Aa, aa will be there
7. Which will give a ratio of 1:2:1 of genotype
8. Here A denotes the dominancy nature and shows the recessive nature
9. They follow Mendel law of segregation, the law of independent assortment, and the law of dominance can be seen among the flowering plant
10. AA will be axial flowers
11. Aa will be axial flowers, Aa will be terminal flowers

	A	a
A	AA	Aa
a	aA	aa

12. Law of dominance means the dominant trait will be shown in the plant phenotype and the recessive one won’t be able to express itself as it will be overtaken by the dominant trait allele.

Note:In Punnett square each allele is assigned a separate column or box first then multiplication and recombination with each allele is done. It also shows which is a dominant trait or recessive trait, purity of genotype can also be seen by this traditional method. This method was given by George, Emily Punnett.