How many homozygous genotypes are possible with 3 alleles?

How many homozygous genotypes are possible with 3 alleles?

six possible genotypes
With three alleles 1, 2, 3 there are six possible genotypes: 11, 12, 13, 22, 23, 33.

What are the possible offspring if one parent is homozygous dominant and the other is homozygous recessive?

For example, if one parent is homozygous dominant (WW) and the other is homozygous recessive (ww), then all their offspring will be heterozygous (Ww) and possess a widow’s peak.

What is a genetic cross between an individual showing a dominant phenotype and a homozygous recessive individual called?

The test cross is another fundamental tool devised by Gregor Mendel. In its simplest form, a test cross is an experimental cross of an individual organism of dominant phenotype but unknown genotype and an organism with a homozygous recessive genotype (and phenotype).

What is an example of a homozygous dominant individual?

A homozygous dominant genotype is one in which both alleles are dominant. For example, in pea plants, height is governed by a single gene with two alleles, in which the tall allele (T) is dominant and the short allele (t) is recessive.

How can you tell if someone is heterozygous or homozygous for a trait that is dominant?

If the test cross results in any recessive offspring, then the parent organism is heterozygous for the allele in question. If the test cross results in only phenotypically dominant offspring, then the parent organism is homozygous dominant for the allele in question.

Why is a homozygous recessive individual used in a test cross?

A test cross is done between the individual showing a dominant phenotype with a homozygous recessive individual to determine the genotype of the individual with the dominant phenotype. The homozygous recessive individual enables the detection of both dominant and recessive allele in progeny.

What is the frequency of homozygous dominant individuals?

According to the Hardy-Weinberg principle, the square root of the homozygous genotype frequency is equal to the allele frequency. The dominant allele frequency is 0.7.

How are genotypes and phenotypes determined when crossed?

When a homozygous dominant individual is crossed with a homozygous recessive individual, the offspring produced will have the heterozygous genotype and show the dominant phenotype. When these heterozygous individuals are crossed, three different genotypes are produced in a ratio of 1:2:1.

What’s the difference between homozygous and heterozygosus cross?

Homozygous vs. Heterozygous. A monohybrid cross between a parent that is homozygous dominant and a parent that is homozygous recessive for a particular trait produces offspring that are all heterozygous for that trait. These individuals have two different alleles for that trait.

Can a heterozygous individual produce a dominant phenotype?

A heterozygous individual crossed with a homozygous dominant individual will always produce offspring with the dominant phenotype. Otherwise, a heterozygous individual crossed with a homozygous recessive individual will always produce offspring with a phenotypic ratio of 1:1.

Which is the best definition of a homozygous allele?

In-Depth Homozygous Definition. Homozygous alleles may be dominant or recessive. A homozygous dominant allele combination contains two dominant alleles and expresses the dominant phenotype (expressed physical trait). A homozygous recessive allele combination contains two recessive alleles and expresses the recessive phenotype.