Difference Between Genes and Alleles With Complete Explanation

Definition of Genes and Alleles

In this interactive lecture, we’ll explore the key differences between genes and alleles. So, let’s begin by asking: “Is an allele a gene?” It’s a common question and can be confusing for students due to the similarity of these terms. However, understanding the distinction is crucial for grasping Mendelian Genetics.

Now, imagine this: if you don’t grasp the concepts of genes and alleles, Mendelian Genetics will remain a mystery to you. But fear not! Our main aim here is to clarify these concepts for you.

Let’s start with genes. A gene is known as the unit of inheritance; it contains the essential information needed to express a specific trait in an organism. The question arises: where are genes located within a cell? Well, genes are found on the chromosome, and the specific spot where a gene resides on a chromosome is called a LOCUS.

By the end of this interactive lecture, you’ll have a crystal-clear understanding of genes and alleles. So, feel free to participate, ask questions, and join in on the learning journey!

As mentioned above, genes contain information that is required to express a particular trait. For example, if a person has black eyes, it means there is a gene that controls the color of the eye. Likewise, for every characteristic, there is a gene. Many people get confused with the terms “character” and “trait,” so it is imperative to understand these similar terms.

Character Vs Trait

What’s the main difference between character and trait in genetics? Let’s dive into this intriguing topic! Imagine you mention “eye color.” Is that enough to distinguish between black or blue eye color? Definitely not! “Eye color” is simply a character. However, when we specify “black eye color” or “blue eye color,” we’re talking about traits. In essence, a character is the general category, while a trait provides specific details within that category.

Let’s explore another example: seed color of peas. Peas come in two seed colors: yellow and green. When we mention “seed color,” we’re referring to the character, not the trait. But when we say “yellow seed color” or “green seed color,” we are precisely discussing traits.

Similarly, consider seed shape in peas: round seed shape and wrinkled seed shape. When we mention only “seed shape,” it represents the character. However, if we say “round seed shape” or “wrinkled seed shape,” we’re focusing on the traits.

With our discussion so far, genes are becoming clearer, and we’re grasping the distinctions between character and traits. Now, let’s move on to explore the fascinating world of alleles! Feel free to engage, ask questions, and let’s continue unraveling the wonders of genetics together!

Definition of Alleles

Alleles are genes that code for a pair of contrasting traits. From the definition, it is clear that alleles are also genes that code for contrasting traits. Well, this definition does not clear the concept of alleles. Let’s take an example to compare genes and alleles from the diagram given below:

If you look at this diagram, A, B, a, b, Y and y are all genes. But, when you consider (A, a), (B, b) and (Y, y), what do you see? All these pairs of genes are present in specific locus. For instance, the locus for gene A and a are the same. And according to the diagram, it is called locus A. Likewise, on locus 2, two genes are present i.e., B, and b. If we consider A and a separately, we can call them genes, but when two genes are present on the same locus, we call them alleles. And each allele pair is responsible for controlling contrasting traits. For instance, if A allele controls round seed shape, small b would control wrinkled seed shape.

Conclusion

Genes and alleles share striking similarities. But here’s where it gets really interesting: when two genes reside on different loci, we refer to them as genes. Now, brace yourself for the twist: when two genes exist on the very same locus, they are called alleles. In simpler terms, alleles are a special kind of genes, but they come in pairs and occupy the same locus.

Let’s visualize this together: imagine genes spread out at different locations, doing their thing. But when we spot two genes side by side, sitting cozily on the same spot, we identify them as alleles. It’s like finding gene buddies hanging out together at a particular address!

In this interactive session, we’re demystifying the world of genetics. So, feel free to jump in with questions, explore the concepts further, and let’s uncover the secrets of genes and alleles together!