Question

What was Mendel's pea plant experiment?

Answer 1

Mendel:

1. Gregor Johann Mendel is known as the Father of Genetics.
2. He conducted hybridization experiments on garden peas for seven years (1856-1863) and proposed the laws of inheritance.
3. Mendel conducted artificial pollination/cross pollination experiments using several true-breeding pea lines (plants that show the stable trait inheritance and
   expression for several generations).

Reasons that Mendel chose the pea plant:

1. The pea plant can be easily grown and maintained.
2. They are naturally self-pollinating but can also be cross-pollinated.
3. It is an annual plant, therefore, many generations can be studied within a short period of time.
4. It has several contrasting characters.

Mendel’s Experiments:

1.Monohybrid Cross

1. In this experiment, Mendel took two pea plants of opposite traits (one short and one tall) and crossed them.
2. He found the first generation offspring were tall and called it F1 progeny.
3. Then he crossed F1 progeny and obtained both tall and short plants in the ratio 3:1.
4. Mendel even conducted this experiment with other contrasting traits like green peas vs yellow peas, round vs wrinkled, etc.

2.Dihybrid Cross

1. In a dihybrid cross experiment, Mendel considered two traits, each having two alleles.
2. He crossed wrinkled-green seed and round-yellow seeds and observed that all the first generation progeny (F1 progeny) were round-yellow.
3. This meant that dominant traits were the round shape and yellow colour.
4. He then self-pollinated the F1 progeny and obtained 4 different traits: round-yellow, round-green, wrinkled-yellow, and wrinkled-green seeds in the ratio 9:3:3:1.

Mendel’s laws:

1. Law of Dominance: According to this, hybrid offspring will only inherit the dominant trait in the phenotype. The alleles that are suppressed are called the recessive traits while the alleles that determine the trait are known as the dominant traits.
2. Law of Independent Assortment: It states that a pair of traits segregates independently of another pair during gamete formation. As the individual heredity factors assort independently, different traits get equal opportunity to occur together.
3. Law of Segregation: It states that during the production of gametes, two copies of each hereditary factor segregate so that offspring acquire one factor from each parent. In other words, allele (alternative form of the gene) pairs segregate during the formation of gamete and re-unite randomly during fertilization.