Mendel's Law of Inheritance - Experiments

The field of science that examines how genes and genetic traits are inherited from one generation to the other is known as genetics. Mendelian genetics is the study of the physical traits of individuals. These are also known as phenotypes.

Gregor Mendel was a 19th-century Augustinian monk and the humble founder of genetics. From 1856 up till 1863, Gregor Mendel tested 28,000 pea plants. From his observations, he deduced two theories. These are now called Mendel's Laws of Inheritance or Mendelian Inheritance.  Mendel described these two laws in a paper called "Experiments on Plant Hybridization", published in 1866.

Read on to learn more about the Gregor Johann Mendel experiment.

Mendel’s Laws of Inheritance

Mendel crossed a true-breeding white flower and a purple flower plant. To his astonishment, he discovered that the product was a purple flower instead of a combination of two colours. He then deduced the idea of "factors" or hereditary units. Of these, one was recessive and the other dominant. Moreover, Mendel stated that these factors, which we now call genes, always occur in pairs.

Mendel then self-fertilised the F1 generation, and in the F2 generation, he observed that the flowers showed phenotypes in the ratio 3:1. Thus, he theorised that genes or these factors could be paired in three combinations: AA, Aa and aa. The capital A stands for the dominant trait while the lowercase a stands for the recessive trait.

Rack Your Brains: Before we move ahead, refresh your concepts by doing a simple task. Search Google or ask your friend for more exciting stuff on Mendel experiment class 10. Then write what you learn in your notebook.

The Gregor Johann Mendel Experiment

Gregor Mendel now decided to analyse the patterns of inheritance in the pea plant. He picked out the pea plant due to the following reasons:

• Peas are self-pollinating. They can also be self-pollinated.

• Peas are annual plants. Thus, many generations of this plant can be examined in a very short span of time.

• Pea plants have a set of 7 distinct character traits.

• Peas are easy to grow.

After that, Mendel began to observe a pair of contrasting traits at a time, and he experimented using true-breeding pea plants. These were the characteristics that he studied.

How well have you learnt about Mendel’s experiments? Test yourself with this quiz.

Pop Quiz 1

1. Which of these is a trait Mendel studied in the pea plant?

1. Leaf shape

2. Leaf colour

3. Flower shape

4. Seed shape

Mendel made sure to use only true-breeding plants in his experiments. True-breeding plants exhibit stable inheritance of traits. Subsequently, in each of his experiments, Mendel noticed a pattern of traits and inheritance. These laid the foundation of his laws of inheritance.

Read on to find out more about the results of the Mendel experiment (class 10).

Results of Gregor Mendel’s Experiments

The following were the observed results of his experiments with the pea plant.

• Firstly, Mendel took note that all plants in the F1 generation were tall and there were no dwarf plants.

• Secondly, in the F2 generation, Mendel made the observation that pea plants were tall, while one was a dwarf plant.

• Consequently, Mendel observed that the same results were seen for other characters as well.

• In the F1 generation, these traits of only one parent came to the fore. Meanwhile, in the F2 generation, these traits of the other parent plant also came to the fore.

• The traits that appeared in F1 are now known as dominant traits, whereas the ones that appeared in the F2 generation are known as recessive traits.

To sum it up, the genes which were passed from one generation to the others were existing in pairs called alleles. Two similar alleles are known as homozygous alleles. Different alleles are called heterozygous alleles.

Test what you know with the following quiz.

Pop Quiz 2

1. A heterozygous yellow pea plant has the following alleles.

1. YY

2. Yy

3. yy

Finally, Mendel's observations led to the three primary Laws of Inheritance.

• Law of Dominance

• The Law of Segregation

• Law of Independent Assortment.

For more on Mendel experiment class 10 and the laws of inheritance, check out our detailed study material. Now you can also download our Vedantu app for easier access to our detailed notes, as well as online interactive sessions for doubt clearing.