When we first learned about genetics, me and my friends were confounded. What was this person talking about? Did it mean that cross-breeding yellow rose and blue rose gave rise to a green rose?
Nope, it didn’t.
However, it gave us a secret formula which would enable us to know the possibility of which colored rose is greater. Hell, the same formula can be used to find out what hair color would a baby whose parents are blond and brunette respectively could have. Whether breeding a potato and tomato would give a Pomato or something else.
We are going to explore and know more about this formula (phenotypic and genotypic ratios) which can be used to know or predict the possibility of an expression of a particular trait in a hybrid plant.
The person who made this all possible was Gregor Mendel.
Mendel was an extremely curious scientific explorer. The main topic of focus in his pea plant experiment was Heredity.
- What is Heredity?
Heredity is described as “the science of transmission of characters from one generation to the next and the mechanism of action of hereditary units as the bring about the characteristics which they control”
Lets take this bit by bit. It is the science (the study of) transmission of characters from one generation to the next (transfer of traits from parents to their kids) and the mechanism of action of hereditary units as they bring about the characteristics which they control. ( how the genes act to bring about the trait in the offspring or child).
- So simply put, Genetics is The study of transfer of traits from parents to their kids through genes and how genes act to bring about or express the particular trait in the child.
This is what Genetics is all about. Now in order to understand the great pea experiment, lets clear a few basics first-
- Genes : The factors controlling a specific trait in the organism is known as a gene. They always occur in pairs. They are responsible for absolutely any trait observed in an organism. The term genetics is derived from genes. They are also known as Hereditary units.
So Genetics is essentially all about genes.
- Some characteristics of Genes:
Mendel studied the expression of characters or traits in pea plant very closely and made three basic laws about the genes. In order to understand these laws better, lets do a preview of Mendelian theory of Genes-
1) There are a number of genes for a particular trait. For example, let the trait be seed shape. So the genes are Round (RR) and Wrinkled (rr).
2) The genes are always in pairs.
3) During breeding or fertilization, only one gene from either of the parent gene pair take part in fertilization.
Eg. R from RR and r from rr combine to from Rr gene pair. Thus, the gene pairs break up during fertilization.
4) A pair of genes is always responsible for a particular trait- from eyebrow shape to eyebrow thickness, there is a pair of genes expressing it.
5) For a particular gene, there is just one pair expressing it. That is the seed shape can be either round or wrinkled. It can extremely rarely be half round and half wrinkled.
- Characters: Different traits are also known as Characters.
So guys, please keep all these things in mind, and your study of genetics will definitely be easier!