Genes can come in 2 different forms called alleles. We represent alleles with both lowercase and uppercase letters. Uppercase and lowercase letters are used to show which alleles are dominant and which are recessive. A dominant (uppercase letter) allele will overpower a recessive allele (lowercase letter).
Is dominant uppercase or lowercase?
Dominant alleles are seen as an uppercase of a letter; for example, B. Recessive alleles are seen as a lower case of a letter; b. In order for a person to show the dominant trait, one of the person’s parents must have the dominant trait (which is an uppercase letter).
Do lower case or upper case letters represent recessive alleles?
In a Punnett square, lower case letters are recessive alleles and upper case letters are dominant alleles. So, “tt” would mean that both alleles are recessive.
How is a dominant allele written?
The dominant allele is by convention written with a capital (upper case) letter. Recessive: In the heterozygous genotype, the expression of one allele is sometimes masked by another. The allele which is masked is said to be recessive. The recessive allele is by convention written with a lower case letter.
Will show in your phenotype even if it only has one copy?
It is almost always expressed even if only one copy is present. An allele that is covered over or dominated by another allele of that trait and seems to disappear. … When an individual is heterozygous for two equally dominant traits. As a result, both alleles for the one trait are expressed equally in the phenotype.
Why do genotypes have 2 letters?
The two letters in a genotype represent the pair of alleles. The uppercase letter represents the dominant allele and the lowercase letter represents recessive allele.
Can be a hidden trait?
Genes come in different varieties, called alleles. … However, an allele that is hidden, or not expressed by an organism, can still be passed on to that organism’s offspring and expressed in a later generation.
Which allele is always written first?
The alleles are represented by letters. The letter chosen is usually the first letter of the trait.
Which allele does a lower case letter stand for?
When writing a genotype, the dominant allele is usually represented by a capital letter, while the recessive allele has a lowercase letter.