Chapter fourteen: Mendel and the Gene Idea

Graph:

In this graph the purple color is the dominant gene which is the B. The small b is the recessive gene. So in the F1 generation there is only 25% chance to get white flower.

Main questions:
1. If the parents’ blood types are AB and A then is the kid possible to have O blood type?

Yes,

2. Which kind of blood type is able to use by anybody?

O type negative

3.
Main Facts:
1. First, alternative versions of genes account for variations in inherited characters.

2. Second, for each character, an organism inherits two alleles, one from each parents.

3. Third, if the two alleles at a locus differ, then one, the dominant allele, determines the organism’s appearance; the other, the recessive allele, has no noticeable effect on the organism’s appearance.
4. Law of segregation: States that the two alleles for a heritable character segregate during gamete formation and end up in different gametes.
5. Parents blood types are A and AB are still possible to have blood type O kid.
Summary:

Key terms:
1. Heterozygous: Having two different alleles for a given gene.

2. Phenotype: The physical and physiological traits of an organism, which are determined by its genetic makeup.

3. Genotype: The genetic makeup, or set of alleles, of an organism.

4. Monohybrids: An organism that is heterozygous with respect to a single gene of interest. All the offspring from a cross between parents homozygous for different alleles are monohybrids.

5. Dihybrids: An organism that is heterozygous with respect to two genes of interest. All the offspring from a cross between parents doubly homozygous for different alleles are dihybrids.

6. Law of independent assortment: Mendel’s second law, stating that each pair of alleles segregates, or assorts, independently of each other pair during gamete formation; applies when genes for two characters are located on different pairs of homologous chromosomes.

7. Incomplete dominance: The situation in which the phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele.

8. Codominance: The situation in which the phenotypes of both alleles are exhibited in the heterozygote because both alleles affect the phenotype in separate, distinguishable ways.

9. Pleiotropy: the ability of a single gene to have multiple effects.

10. Epistasis: A type of gene interaction in which one gene alters the phenotypic effects of another gene that is independently inherited.

Video:http://www.youtube.com/watch?v=d4izVAkhMPQ