Search results
Results from the WOW.Com Content Network
The Punnett square is a square diagram that is used to predict the genotypes of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach in 1905. [3][4][5][6][7][8] The diagram is used by biologists to determine the probability of an offspring having a particular genotype.
Genotype frequency in a population is the number of individuals with a given genotype divided by the total number of individuals in the population. [2] In population genetics, the genotype frequency is the frequency or proportion (i.e., 0 < f < 1) of genotypes in a population. Although allele and genotype frequencies are related, it is ...
Punnett square for three-allele case (left) and four-allele case (right). White areas are homozygotes. Colored areas are heterozygotes. Consider an extra allele frequency, r. The two-allele case is the binomial expansion of (p + q) 2, and thus the three-allele case is the trinomial expansion of (p + q + r) 2.
In a Punnett square, the genotypes of the parents are placed on the outside. An uppercase letter is typically used to represent the dominant allele, and a lowercase letter is used to represent the recessive allele. The possible genotypes of the offspring can then be determined by combining the parent genotypes. [10] In the example on the right ...
Test cross types. A test cross involves crossing an individual organism with a dominant genotype or phenotype with another organism exhibiting a recessive genotype or phenotype. To better grasp the concept of test crossing, let's explore various types of crosses involving one or more genes of interest.
Dihybrid cross. Dihybrid cross is a cross between two individuals with two observed traits that are controlled by two distinct genes. The idea of a dihybrid cross came from Gregor Mendel when he observed pea plants that were either yellow or green and either round or wrinkled. Crossing of two heterozygous individuals will result in predictable ...
Punnett square of the possible genotypes and phenotypes of children given genotypes and phenotypes of their mother (rows) and father (columns) shaded by phenotype. Blood groups are inherited from both parents. The ABO blood type is controlled by a single gene (the ABO gene) with three types of alleles inferred from classical genetics: i, I A ...
A Punnett square for one of Mendel's pea plant experiments – self-fertilization of the F1 generation. The Law of Segregation of genes applies when two individuals, both heterozygous for a certain trait are crossed, for example, hybrids of the F 1-generation.