Inheritance of One Gene Notes

We never wonder why Lion can give birth to Lions only, or why a bird can reproduce in the same species and no other species. Not everything is possible, Isn’t it?  Also, No human being look exactly identical, even with twins there are differences in every individual. Some siblings look similar while at the same time, some look really different. 

Have you ever thought about who causes all these differences? All these questions are answered in the branch of science named Genetics. In this article, we will know more about the Inheritance of one gene. 

Introduction to Inheritance and Variation

Inheritance is understanding how fundamental trait is passed down from generation to generation. Variation refers to the differences that exist between individuals of the same species. It’s the raw material of evolution. Both Inheritance and Variation are the basic concepts of genetics and evolution. 

Inheritance of one gene means that we get some of our traits (like the color of our eyes or hair) from our parents. We have different versions of a gene that controls these traits, and we get one version from our mom and one from our dad. Sometimes one version of the gene is stronger and it makes our trait look a certain way. But sometimes, both versions are kind of equal, and our trait ends up looking like a mix of both.

So when you look more like your mom or dad, it’s because you inherited some of their genes!

The Story Behind Mendel’s Laws of Inheritance 

Mendel’s laws of inheritance are a set of fundamental principles that describe how traits are passed down from one generation to the next. The story begins in the mid-19th century when Gregor Mendel, Father of genetics, a monk living in a monastery in Brno (now in the Czech Republic), conducted a series of experiments with pea plants. 

Mendel was curious about how traits are passed from one generation to another. But why only pea plants for the experiment? Because they were easily available, easy to grow, and had easily observable traits, such as seed color, flower color, and pod shape. His involved crossing pea plants with different traits and observing the traits of their offspring. He then analyzed the results of these crosses and derived a set of fundamental principles that described how traits were inherited and published his findings in 1866 in a paper called “Experiments in Plant Hybridization,” but his work was largely ignored at the time. The three laws of inheritance are:

1. Law of Segregation: This law states that each individual organism possesses two copies (alleles) of each gene, one inherited from each parent, meaning that each parent gives one copy of their traits to their child.
2. Law of independent assortment: This law states that genes for different traits are passed down separately from each other.
3. Law of dominance: This law states that one gene is more dominant than the other. 

Overall, these rules help us understand how we inherit traits from our parents, and why we look similar or different from them.

Inheritance of One Gene 

We can understand this concept through one of Mendel’s experiments, where he crossed tall and dwarf pea plants to study the inheritance of one gene.

• 1st Generation – He took one tall pea and one dwarf pea, as parents and got all tall peas, with no dwarf plants. 
• 2nd Generation – In the next experiment, he took the seed of tall peas from the first generation and got a mix of dwarf and tall pea plants. 

Based on these observations, he proposed that both genes are passed down to generations in the form of alleles. He called these things as ‘factors’, Now we call them genes. When two parents are not similar, one of the gene traits is dominant while the other is recessive in a child. 

His observation on monohybrid crosses led to Principals or laws of Inheritance, we will discuss two in this article. 

Law of Segregation

This law is based on the fact that the gene does not show any blending on itself and both the characters of a parent are present. In some cases, one can be dominant or a mix of the characters. As in Mendel’s experiment, 1st generation showed all tall peas but the 2nd generation had both dwarf and tall peas.

Concept of Dominance:  Every gene contains some kind of information in itself. Information about the character of a parent or a particular trait. The concept of dominance in genetics refers to how certain versions of a gene, called alleles, can have a stronger effect on a trait than others.

Law of Dominance:

It states the effects on the Characters that are controlled by discrete units called factors and In a dissimilar pair of factors one member of the pair dominates (dominant) the other (recessive).

Conclusion

In this article, we saw who started the study of genetics first and how it led to the principle of inheritance. Now can you answer why you are different from your siblings? 

FAQs on Mendel’s Laws of Inheritance

Q1. Mention the advantages of selecting a pea plant for the experiment by Mendel.

Ans: Peas were easy to grow, providing a large number of offspring, and give distinct traits. Also, One of the major reason was Pea plants can self-fertilize, meaning that they can reproduce with themselves, or be cross-fertilized, meaning that the pollen from one plant is transferred to the stigma of another plant. This allowed Mendel to control the breeding of the plants and study the inheritance of traits under different conditions.

Q2. Why the study of genetics is important? 

Ans: It is important to understand inheritance so that we can try to prevent disease, provide personalize medicine and understand evolution.

Q3. Do they Define Gender as well? 

Ans: Genetics plays a role in determining an individual’s sex, which is often colloquially referred to as gender. Sex is determined by the presence of either an X or a Y chromosome in an individual’s genetic makeup.

Q4. Is there a possibility that we can control reproduction products by understanding genes? 

Ans: Understanding genes and their role in reproduction can potentially give us more control over the reproductive process. With the advancements in genetic engineering techniques, it is now possible to manipulate genes in a targeted manner.