Are tall genes dominant?

Quick Peek:

If two parents are both carriers of the “tall” and “short” gene, what are the chances their child will be short? According to Interesting Engineering, if both parents are heterozygous for the height gene, there is a 25% probability their offspring will be short. Understanding genetics can help answer questions about traits and inherited characteristics. Don’t worry, it’s not rocket science!

Are Tall Genes Dominant?

As humans, we have always been fascinated by the traits we inherit from our parents. Some of us are born with curly hair, others with straight hair, some with blue eyes, and others with brown eyes. But what about height? Is it determined by dominant or recessive genes? Let’s dive into the world of genetics and find out.

The Basics of Genetics

Before we can understand whether tall genes are dominant or not, we need to know a little bit about genetics. Genes are segments of DNA that determine our traits. We inherit one copy of each gene from each parent, which means we have two copies of each gene.

When it comes to height, there are many genes involved. However, for the sake of simplicity, let’s focus on just one gene that determines whether we are tall or short. This gene has two versions, or alleles: T and t. The T allele is dominant, while the t allele is recessive.

Heterozygous Parents

Now, let’s consider a scenario where both parents are heterozygous for the height gene. This means that they each have one copy of the T allele and one copy of the t allele. When they have a child, there are four possible combinations of alleles that the child could inherit:

Since the T allele is dominant, any child who inherits at least one copy of the T allele will be tall. This means that only the child who inherits two copies of the t allele will be short.

What is the Probability of a Short Child?

So, what is the probability of a child being phenotypically short in this scenario? To answer this question, we need to use Punnett squares.

A Punnett square is a grid used to predict the possible genotypes of offspring in a cross between two individuals. In this case, we can use a Punnett square to determine the probability of a child inheriting two copies of the t allele.

When we create a Punnett square for two heterozygous parents, we get the following:

	T	t
T	TT	Tt
t	tT	tt

As you can see, there are four possible combinations of alleles that the child could inherit. Only one of these combinations (tt) results in a child who is phenotypically short.

Therefore, the probability of a child being phenotypically short in this scenario is 1/4 or 25%.

Conclusion

In conclusion, the trait “tall” is dominant while “short” is recessive. If both parents are heterozygous for the height gene, there is a 25% chance that their child will be phenotypically short.

While genetics can be complex, understanding the basics can help us answer some of the questions we have about our traits. So, the next time you wonder whether your height is determined by dominant or recessive genes, you’ll know the answer.