Genetics-Mendel-experiment | UKsir-notes | Genetics-2

Genetics (Mendel’s Experiment )

Mendel's Experiment:

Mendel working

Want to know about History of Genetics and Mendel , Click the link below:

https://uksirnotes.blogspot.com/2021/07/genetics-history-mendel-uksir.html

Experiment:

Mendel Choose Garden Pea (Pisum sativum) for his experiment.

Garden pea

Reasons for Mendel’s success:

- Many Scientist failed before Mendel, who had considered many characters at a time.

-        But, Mendel studied the inheritance of one or two characters at a time

Material selection advantages (garden pea) like –

- Small size plants can easily managed

-Easy to grow in most of the environments.

-Short life time (can grow 2 times in a year)

- Flowers are bisexual & Self pollinated

- The varieties could be artificially cross pollinated.

- Pea seeds are larger can be studied well.

- Pea plants have specific contrasting / Alternative characters, which were very much helpful in study of Inheritance.

Contrasting characters of Pea plant:

Mendel took 7 contrasting characters, which had clear cut alternative forms:

 

Sl. No	Character	Dominant Form	Recessive Form
1	Seed shape	Round	Wrinkled
2	Seed Color	Yellow	Green
3	Flower Color	Violet	White
4	Pod/ Fruit Shape	Full/ Inflated	Constricted
5	Pod Color	Green	Yellow
6	Flower Position	Axial	Terminal
7	Plant Height	Tall	Dwarf

Contrasting-character-pisum-stivum-pea

Mendel's Hybridization/ crossing Technique:

Parent selection:

He took healthy superior plants & allow them for self pollination to produce Pure lines.

This is done for generations to obtain pure character.

Then he allowed the parents for flowering.

Emasculation: (Removal of anther)

 When the flowers are produced, he cut off the anther to produce pure female flower & avoid self pollination.

Bagging-Tagging

Bagging :

He covered the flower with plastic /paper pouch to avoid unwanted pollination.

Tagging :

It is the record of time, date & identification of the flower on which experimenting.

Hybridization / Cross pollination:

After maturity of flower, He took the pollen grain from Selected flower & put it on the stigma of the tagged flower.
Thus he crossed between two desire plants with desire character.

The new Generation produced (after Seed germination) is called first filial Generation (F1-generation).

The f1- generation is hybrid of two pure parents.
He again crossed the plants of F1 generation in same method & produce F2 generation.

emasculation and fertilization

Pollination

All these events / experiments formed by him very carefully.
    He considered those specific characters, which were easily countable.
    He avoided unwanted crosses carefully.
    He arranged the results / data statistically & analyzed them for final result.

He performed many type of crosses like:

Taking 1 character for consideration – Monohybrid Cross

Taking 2 character for consideration – Dihybrid Cross

Taking 3 characters for consideration – Trihybrid Cross etc.

Want to know about History of Genetics and Mendel , Click the link below:

https://uksirnotes.blogspot.com/2021/07/genetics-history-mendel-uksir.html

Thanks for visiting, feel free to ask doubts in comment section... UK Sir