Answer to Question #292445 in Genetics for Smilynne

Question

14. What does Mendel's law of segregation say? When in meiosis does this 

segregation occur?

15. How can two organisms have the same genotype but different phenotypes? For 

instance, why aren't identical twins (who have the same DNA) exactly the same in 

every way?

16. What does the law of independent assortment say? When in meiosis does 

independent assortment occur? In what cases does this law not hold true?

17. Can you draw Punnett Squares for crosses of up to 2 genes at once? If I tell you 

that alleles are completely dominant, incompletely dominant, epistatic, or 

codominant, can you tell me which genotype codes for which traits? Can you draw 

Punnett squares for sex-linked traits?

18. Be familiar with how the ABO blood types work. What kind of dominance do the 

alleles for blood types show?

Answer 1

According to the law of segregation, only one of the two gene copies present in an organism is distributed to each gamete (egg or sperm cell) that it makes, and the allocation of the gene copies is random.

Due to the presence of a dominant allele, the same phenotype but distinct genotype is possible. A dominant allele always expresses itself when it is present in the genotype. ... The other allele is known as recessive when a dominant allele is entirely dominant over another allele.

Mendel's law of independent assortment states that the alleles of two (or more) different genes get sorted into gametes independently of one another. In other words, the allele a gamete receives for one gene does not influence the allele received for another gene.

Both A and B alleles are dominant over O. ... The A and B alleles are codominant. Therefore, if an A is inherited from one parent and a B from the other, the phenotype will be AB. Agglutination tests will show that these individuals have the characteristics of both type A and type B blood