New York, NY IMG HI 58° LO 56° Home About Contact
IMG-LOGO
Home Biomedical Engineering Biology Class 12 Mendelian inheritance using seeds of different colour/sizes of any plant
Biology Class 12 Lab Experiments

Mendelian inheritance using seeds of different colour/sizes of any plant



Aim: Mendelian inheritance using seeds of different colour/sizes of any plant

Theory:

Mendel hybridized or crossed pollinated plants with alternate forms of one or more traits. He performed monohybrid, dihybrid and polyhybrid crosses and formulated basic law of heredity. These laws are:

1. Law of dominance: when two factors (genes) of a pair of contrasting characters are bought together in a cross, only one of them express itself in the resulting hybrids. The character expressed is said to be dominant and the other which remains suppressive is called recessive.

2. Law of segregation: two factors (alleles) of charters separate or segregate from each other during gamete formation and the paired condition is restored by the random fusion of gametes during fertilization.

3. Law of independent assortment: when the factors (genes) for different characters inherited from parents, do not remain linked in the offspring, but their distribution in the gametes and in the progeny of subsequent generation is independent of each other.

The characters which follow the Mendel laws during inheritance are called mendelian traits.

Material/Apparatus Required:

  • Peas seeds samples
  • Petri dish
  • Notebook
  • Pencil/ pen

Procedure:

  1. Take about 100 pea seeds in a tray.
  2. Separate out round and wrinkled and put in separate Petri dish.
  3. Note down the number of round and wrinkled seed and calculate their appropriate ratio.
  4. Repeat the process for the other contrasting traits of the seed i.e., yellow and green colour.

Observation Table:

S. No. Character / traits of the seed Total no. of seed observed No. of seed showing contrasting form of the trait Appropriate ratio
1 Seed shape (Round/ wrinkled)
2 Seed shape (yellow/green)

Result:

The contrasting forms in both the traits of pea seed (i.e., seed shape and seed colour) show an approximate ratio of _____.

Precautions:

Observe the contrasting traits carefully and take sufficient large number of seed for analysis to minimize the error.