Question

One plant with a dominant tall height bearing purple flowers is crossed with another plant with recessive dwarf, white flowers.
a) What do the plants of the F1 generation look like?
b) What type of a cross is it?
c) What is the phenotypic ratio in the F2 generation? Name the types of plants obtained according to the phenotypic ratio.

Answer 1

Hint: The first filial generation is referred to as the F1 generation. Filial generations are the names assigned to successive generations of offspring from regulated or witnessed reproduction. For parental age, the letter "P" is assigned to the first generation.

Complete answer:
a) A plant with dominant tall and purple flowers is expressed as TTPP. Recessive dwarf and white flower ttpp. They will form gametes TP and tp.
F1 generation - When they are crossed TP X tp
The offspring will be a hybrid and look like Tall and purple TtPp. Tall is dominant over dwarf and purple is dominant over white.

b) A dihybrid cross is a cross between two species that are similar hybrids with two traits. A dihybrid cross is a cross between two species that are heterozygous for two distinct traits. Individuals of this allele are homozygous with a particular trait. These characteristics are determined by DNA segments known as chromosomes. Since height and color are considered together here, it is a dihybrid cross.

c) In the F2 generation, the offspring obtained in the F1 generation will be crossed.
The gametes formed are TP, Tp, tP, tp
The cross is represented by punnett square as:

	TP	Tp	tP	tp
TP	TTPP (Tall, purple)	TTPp (Tall, purple)	TtPP (Tall, purple)	TtPp (Tall, purple)
Tp	TTPp (Tall, purple)	TTpp (Tall, white)	TtPp (Tall, purple)	Ttpp(Tall, white)
tP	TtPP (Tall, purple)	TtPp (Tall, purple)	ttPP (Dwarf, purple)	ttPp (Dwarf, purple)
tp	TtPp (Tall, purple)	Ttpp (Tall, white)	ttPp (Dwarf, purple)	ttpp (Dwarf, white)

This 9:3:3:1 phenotypic ratio is the classic Mendelian ratio for a dihybrid cross in which two separate genes' alleles range separately into gametes. The observed phenotypic ratio is 9:3:3:1, with the phenotype purple & tall : purple & dwarf : white & tall : white & dwarf which means dominant & dominant: dominant & recessive : recessive & dominant : recessive & recessive

Additional information: The dihybrid cross demonstrates all of the potential offspring that can be produced by two provided parents. Mendel's Law of Independent Assortment, which specifies that the inheritance of one character does not impair the inheritance of another, is the basis for the cross.

Note: Crosses with several traits will also help us figure out what kind of inheritance structure rules each trait.
- This is since each cross gives us a particular phenotypic ratio, or how many of the potential offspring have a specific phenotype.
- In his studies, Mendel used seven pea plant traits: flower color (purple or white), flower position (axil or terminal), stem length (long or short), seed shape (round or wrinkled), seed color (yellow or green), pod shape (inflated or constricted), pod color (yellow or green), and pod color (yellow or green) (yellow or green).