What letter combination is heterozygous?

Heterozygous always means one of each letter, so we’d use “Tt” (where “T” = tall, & “t” = short). The only way for a pea plant to be short is when it has 2 lowercase “t’s”, so that short parent is “tt”.

What combination is heterozygous?

Heterozygous means that an organism has two different alleles of a gene. For example, pea plants can have red flowers and either be homozygous dominant (red-red), or heterozygous (red-white). If they have white flowers, then they are homozygous recessive (white-white).

What combination of letters represent a heterozygous genotype?

A capital letter and a lower case letter of the alphabet are used to represent heterozygous traits (Aa). Describes a trait that has two of the same alleles. Two capital letters (AA) or two lower case letters (aa) are used to represent homogzygous traits. “AA” is homozygous dominant.

Is the allele combination DD homozygous or heterozygous?

Sally’s genotype is “dd”, so she is also considered homozygous. Susan’s genotype is “Dd”, so she is considered HETEROZYGOUS (has two different alleles for a specific gene). Although Susan has both the allele “D” to make dimples and the allele “d” in her genotype, her phenotype is the presence of dimples.

What’s an example of heterozygous?

For every gene, you inherit two alleles: one from your biological father and one from your biological mother. … If the two versions are different, you have a heterozygous genotype for that gene. For example, being heterozygous for hair color could mean you have one allele for red hair and one allele for brown hair.

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What are examples of homozygous?

Homozygous examples

  • Eye color. The brown eye color allele is dominant over the blue eye allele. You can have brown eyes whether you’re homozygous (two alleles for brown eyes) or heterozygous (one for brown and one for blue). …
  • Freckles. Freckles are tiny brown spots on the skin. …
  • Hair color. Red hair is a recessive trait.

Is TT homozygous dominant?

When an organism has two of the same alleles for a specific gene, it is homozygous (homo means “same”) for that gene.

Genotype and Phenotype.

Genotype Definition Example
Heterozygous One dominant allele and one recessive allele Tt
Homozygous dominant Two dominant alleles TT
Homozygous recessive Two recessive alleles tt

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.

Why are genotypes written with two letters?

genotype = the genes of an organism; for one specific trait we use two letters to represent the genotype. A capital letter represents the dominant form of a gene (allele), and a lowercase letter is the abbreviation for the recessive form of the gene (allele).

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