Alleles are different versions of a gene. They are really important for understanding how traits are passed down from parents to their children. This is what Mendelian genetics is all about—how these alleles work together to decide the traits we see in offspring. Let’s take a closer look at why alleles are so important.
An allele is a specific version of a gene found on a chromosome.
Think about the gene that decides flower color in pea plants. This gene can have two alleles:
Each plant gets two alleles for this gene—one from its mother and one from its father.
Mendel’s studies helped us understand that alleles can be either dominant or recessive.
A dominant allele is the one that shows its effect even if the other allele is different.
So, if a plant has one dominant (P) and one recessive (p) allele, its flowers will be purple. The purple color hides the effect of the white allele.
The set of alleles that an organism has is called its genotype.
For our flower color example, there are three possible genotypes:
What we see—like the color of the flowers—is called the phenotype:
To figure out what traits their offspring might have, scientists often use a tool called a Punnett square.
For example, if we cross two plants that are heterozygous (Pp x Pp), the Punnett square helps us see the possible genotypes for the baby plants:
From this, we can expect a flower color ratio of 3 purple to 1 white. This shows us how alleles control inheritance.
In short, alleles are key players in how traits are passed down through generations. By learning about these concepts, we can better understand genetic diversity and how traits are inherited in living things.
Alleles are different versions of a gene. They are really important for understanding how traits are passed down from parents to their children. This is what Mendelian genetics is all about—how these alleles work together to decide the traits we see in offspring. Let’s take a closer look at why alleles are so important.
An allele is a specific version of a gene found on a chromosome.
Think about the gene that decides flower color in pea plants. This gene can have two alleles:
Each plant gets two alleles for this gene—one from its mother and one from its father.
Mendel’s studies helped us understand that alleles can be either dominant or recessive.
A dominant allele is the one that shows its effect even if the other allele is different.
So, if a plant has one dominant (P) and one recessive (p) allele, its flowers will be purple. The purple color hides the effect of the white allele.
The set of alleles that an organism has is called its genotype.
For our flower color example, there are three possible genotypes:
What we see—like the color of the flowers—is called the phenotype:
To figure out what traits their offspring might have, scientists often use a tool called a Punnett square.
For example, if we cross two plants that are heterozygous (Pp x Pp), the Punnett square helps us see the possible genotypes for the baby plants:
From this, we can expect a flower color ratio of 3 purple to 1 white. This shows us how alleles control inheritance.
In short, alleles are key players in how traits are passed down through generations. By learning about these concepts, we can better understand genetic diversity and how traits are inherited in living things.