Dominant Vs. Recessive Alleles — Reading Comprehension

Have you ever noticed how some people in a family have similar features, like the same eye color or hair type, while others look quite different? This is all thanks to something called heredity – the passing of traits from parents to their children. These traits, whether they're eye color, hair texture, or even if you can roll your tongue, are determined by tiny instructions inside our bodies called genes.

Each gene comes in different versions, and these versions are called alleles. For most traits, you inherit two alleles, one from your mother and one from your father. What makes things interesting is how these alleles interact. We often talk about two main types: dominant alleles and recessive alleles.

A dominant allele is like the bossy one. If you inherit even one dominant allele for a particular trait, that trait will show up. For example, let's consider eye color. If brown eyes are determined by a dominant allele and blue eyes by a recessive allele, and you get a brown eye allele from one parent and a blue eye allele from the other, you will have brown eyes. The brown eye trait 'dominates' over the blue eye trait. We call the set of alleles you have your genotype, and the trait you actually see (brown eyes) is your phenotype.

On the other hand, a recessive allele is a bit shyer. A recessive trait will only show up if you inherit two copies of the recessive allele – one from each parent. Using our eye color example, to have blue eyes, you would need to inherit a blue eye allele from your mother AND a blue eye allele from your father. If you get a dominant brown eye allele and a recessive blue eye allele, the dominant brown eye trait will be expressed. Understanding dominant and recessive inheritance helps explain the variation of traits we see in families and across populations.

So, the next time you look in the mirror or at your family members, remember that a complex dance of dominant and recessive alleles is at play, shaping the unique individuals we all are. These genetic principles are fundamental to understanding biological inheritance.

Interesting Fact: Human earlobes can be attached or unattached, and this trait is determined by a single gene with dominant (unattached) and recessive (attached) alleles!

What determines traits like eye color?

How many alleles do you inherit for most traits?

Which allele type acts 'bossy'?

What is the genotype of an individual?

If brown eyes are dominant, what color eyes will a child have if they inherit a brown allele and a blue allele?

A recessive trait shows up only if two copies are inherited.

What does 'heredity' refer to?

Why might siblings have different eye colors?

If a plant has red flowers (dominant) and white flowers (recessive), and you see a red flower, what do you know about its alleles?

Which scenario best describes a recessive trait appearing?