Biology 120 Notes (Part 19) Continuing the Discussion of Genetic Disorders

Codominance

occurs when two dominant alleles are equally expressed.

Polygenic Inheritance

occurs when a trait is governed by two or more sets of alleles, i.e., AaBbCc.

Pleiotropy

occurs when a single mutant gene affects two or more distinct traits.

Modern genetics

has expanded the range of Mendelian genetics.

X-Linked Inheritance

refers to genes that are located on the x chromosome but have nothing to do with gender.

Incomplete Dominance

occurs when the heterozygous phenotype is intermediate between homozygous dominant and recessive phenotypes.

Multiple alleles

There are several variations of Mendelian genetics which include: , Codominance, Incomplete Dominance, Pleiotropy, Polygenetic Inheritance, and X- Linked Inheritance.

There are several variations of Mendelian genetics which include

Multiple alleles, Codominance, Incomplete Dominance, Pleiotropy, Polygenetic Inheritance, and X-Linked Inheritance

There are three possible allele combinations

IA (A antigen is on the red blood cells), IB (B antigen is on the red blood cells), and i (there are neither A nor B antigens on the red blood cells)

Some examples include Cystic Fibrosis and Sickle Cell

• severe anemia, poor circulation, pain, high fever, spleen damage, paralysis

The three possible allele combinations are:

IA (A antigen is on the red blood cells), IB (B antigen is on the red blood cells), and i (there are neither A nor B antigens on the red blood cells).

Hemophilia

___ causes internal bleeding.

Muscle Dystrophy

is the wasting away of muscles

Mendelian genetics

is "the study of the pattern of segregation of phenotypes under the control of genetic loci taken one at a time.

Multiple alleles

__ describes how several alleles for a given trait exist in a population.

A phenotype

For the _, the genotype can be IAIA or IBi.

B phenotype

For the _, the genotype can be either be IBIB or IBi.

AB phenotype

For the _, the genotype can only be IAIB.

O phenotype

For the __, the genotype can only be ii.

Loci

is "a plural of the word "locus" and "locus" is the position of a chromosome where a particular genetic trait presides." Sometimes used to describe multiple genes that affect the same function."