Types Of Mutations: Point, Insertion, Deletion

Back to: MICROBIOLOGY 200 LEVEL

Welcome to class!

My brilliant friend, welcome back! You’ve been on a roll, and it’s always such a joy to learn together. Today, we’re looking at something very fascinating and important — Types of Mutations: Point, Insertion, and Deletion. These might sound serious, but don’t worry — we’ll make it as clear and familiar as possible, just like explaining a Nollywood story to a friend. Let’s go!

Types Of Mutations: Point, Insertion, Deletion

Imagine you’re reading a recipe to cook party jollof rice. Now, what if one word was misspelt, one ingredient was added twice, or a line was missing entirely? That recipe would turn out confusing, right? The same thing happens when a cell’s genetic “recipe” gets altered — this is what we call a mutation.

A mutation is a change in the DNA sequence. Sometimes it’s small, like changing one letter in a word, and sometimes it’s big, like deleting an entire sentence from a paragraph. These changes can affect how proteins are made in the body and how cells function.

Point Mutation

A point mutation happens when one single base in the DNA is changed.

It’s like changing one letter in a word: “cat” to “bat”.

There are three kinds of point mutations:

Silent mutation – the change doesn’t affect the amino acid (like changing “colour” to “color” — same meaning).

Missense mutation – the change leads to a different amino acid being produced.

Nonsense mutation – the change introduces a stop codon, cutting the protein short.

Insertion Mutation

An insertion happens when extra base pairs are added to the DNA sequence.

It’s like adding an extra ingredient in a recipe that wasn’t needed.

This can shift the entire sequence — what we call a frameshift mutation — and may result in a totally non-functional protein.

Deletion Mutation

A deletion occurs when one or more bases are removed from the DNA.

Imagine leaving out a crucial step from a recipe — it could spoil the whole meal!

Like insertion, this can also cause a frameshift, changing how the rest of the sequence is read.

Think of your DNA as a line of words in a text message.

Original message: “The big fat dog ran.”

Point mutation: “The big fit dog ran.” (just one letter changed)

Insertion: “The big fat red dog ran.” (new word added)

Deletion: “The big at dog ran.” (letter removed — sentence now sounds strange)

Just like in real life, one small mistake in a message can change the entire meaning — that’s the power of mutations.

Summary

• Mutations are changes in the DNA sequence.
• Point mutation changes a single base and can be silent, missense, or nonsense.
• Insertion adds extra bases, possibly causing a frameshift mutation.
• Deletion removes bases from the DNA, also potentially causing a frameshift.
• Mutations can affect how proteins are made, leading to health effects or sometimes no effect at all.

Evaluation

1. What is a point mutation?
2. Give an example of a missense mutation.
3. How does an insertion mutation affect protein production?
4. What is a frameshift mutation?
5. Describe the difference between deletion and insertion mutations.

You’ve just tackled another powerful topic, and you did it with confidence! Mutations may sound scary, but understanding them gives you super-scientist insight into how our bodies work — and how things sometimes go wrong. With Afrilearn by your side, you’re building not just knowledge but a bright and purposeful future. Keep shining, and I’ll see you in our next exciting lesson!