How many distinct heterozygous genotypes are possible?
How many distinct heterozygous genotypes are possible? 21. With independent assortment, the ratio of genotypes in the F2 generation of a cross between true-breeding strains (AA bb × aa BB) can be described as 1:2:1:2:4:2:1:2:1.
What are the genotypes for homozygous?
A homozygous genotype means that you have two of the same alleles, which are represented by the letters A or a. So if an individual has AA or aa, we say they are homozygous. If that have Aa, they are heterozyous.
How many homozygous alleles are there?
Genotypes are described as homozygous if there are two identical alleles at a particular locus and as heterozygous if the two alleles differ. Alleles contribute to the organism’s phenotype, which is the outward appearance of the organism. Some alleles are dominant or recessive.
How many genotypes can be produced from four phenotypes?
These nine genotypes can be grouped into four phenotypes, for example 1 YYRR + 2 YYRr + 2 YyRR + 4 YyRr = 9Y-R- round, yellow peas.
How many genotypes are possible?
A description of the pair of alleles in our DNA is called the genotype. Since there are three different alleles, there are a total of six different genotypes at the human ABO genetic locus. The different possible genotypes are AA, AO, BB, BO, AB, and OO. How are blood types related to the six genotypes?
How many genotypes are possible with 6 alleles?
Consider the case, though, of a locus with 6 alleles. It has 21 possible genotypes — 6 kinds of homozygotes and 15 kinds of heterozygotes. Writing it out, 6 + 5 + 4 + 3 + 2 + 1 = 21 = [6*(6+1)]/2 — this is the formula for combinations of six things taken two at a time, order unimportant — [n(n+1)] / 2.
What is the genotype of the heterozygote?
Listen to pronunciation. (HEH-teh-roh-ZY-gus JEE-noh-tipe) The presence of two different alleles at a particular gene locus. A heterozygous genotype may include one normal allele and one mutated allele or two different mutated alleles (compound heterozygote).
How many alleles are required to express a Monohybrid trait?
Mendel showed the classic 3:1 phenotypic ratio of a monohybrid cross (one trait present in two forms, or alleles), although the terms ‘phenotype’ (an individual’s appearance) and ‘genotype’ (the gene variants present) were not yet in use.
Is the genotype ee heterozygous or homozygous?
The person with the Ee genotype is heterozygous for the trait, in this case, free earlobes. An individual is heterozygous for a trait when it has two different allelic forms of a particular gene.
How many heterozygous alleles are there in these homologous chromosomes?
Heterozygous (and its less common form heterozygotic) means “relating to a cell that has two different alleles for a particular gene at corresponding positions on homologous chromosomes.”
How many homozygous alleles are in these homologous chromosomes?
Diploid organisms that are homozygous for a gene have two identical alleles, one on each of their homologous chromosomes. The genotype is often written as YY or yy, for which each letter represents one of the two alleles in the genotype. The dominant allele is capitalized and the recessive allele is lower case.
How many copies of a dominant allele are needed for that trait to show up?
Dominant alleles show their effect even if the individual only has one copy of the allele (also known as being heterozygous?). For example, the allele for brown eyes is dominant, therefore you only need one copy of the ‘brown eye’ allele to have brown eyes (although, with two copies you will still have brown eyes).
How many different phenotypes are possible?
There are three common alleles in the ABO system. These alleles segregate and assort into six genotypes, as shown in Table 1. As Table 1 indicates, only four phenotypes result from the six possible ABO genotypes.
How many genotypes are possible with 8 alleles?
Therefore, 8 alleles of a gene can have 36 possible genotypes in the population.
How many genotypes are possible with 2 alleles?
With 2 alleles, the number of genotypes is 1 + 2 = 3. 3 alleles there are 1 + 2 + 3 = 6 genotypes. 4 alleles there are 1 + 2 + 3 + 4 = 10 genotypes.