What fraction of offspring would be homozygous dominant for at least one trait?
In any cross involving at least one parent that is homozygous dominant (2 CAPITAL letters), 100% of the offspring will have the dominant trait in their phenotype.
What fraction of the offspring is heterozygous?
On average, half of the children will be heterozygous (Aa) and, therefore, carriers. The remaining half will inherit 2 recessive alleles (aa) and develop the disease. It is likely that every one of us is a carrier for a large number of recessive alleles.
What fraction of this cross will be recessive for both traits?
The correct answer is 1/16. A dihybrid cross results in a phenotypic ratio of 9:3:3:1. The 1 in the ratio is indicative of the double recessive phenotype, with a homozygous recessive genotype for both traits. Thus, only 1/16 of the offspring will display both recessive phenotypes.
Which parent is homozygous for the dominant trait?
~homozygous dominant parents means each parent has 2 dominant (rolling tongue) alleles. Therefore, each parent has no choice but to pass on those dominant alleles to their offspring (RR). All offspring, 4/4 will also be homozygous and able to roll their tongues.
How do you find the percentage of heterozygous?
The percentage of heterozygous individuals (carriers) in the population. Answer: Since 2pq equals the frequency of heterozygotes or carriers, then the equation will be as follows: 2pq = (2)(.
- The frequency of the recessive allele. …
- The frequency of the dominant allele. …
- The frequency of heterozygous individuals.
What is the probability of a heterozygous offspring?
The possibilities are summarized: There is a 50% x 50% = 25% probability that both of the offspring’s alleles are dominant. There is a 50% x 50% = 25% probability that both of the offspring’s alleles are recessive. There is a 50% x 50% + 50% x 50% = 25% + 25% = 50% probability that the offspring is heterozygous.
When you cross 2 heterozygous individuals in a Dihybrid cross what fraction of the offspring will be dominant for both traits?
Explanation: When crossing organisms that are heterozygous for two traits, the result is a dihybrid cross. The phenotypic ratio of a heterozygous dihybrid cross for autosomal (none-sex-linked) traits is always 9:3:3:1. Nine offspring will show both dominant traits (AABB, AaBB, AABb, AaBb).