L21 - Genetics and Inheritance

Flashcards on genetics lecture notes, covering topics such as key genetic terms, protein synthesis, chromosomes, earwax genetics, blood groups, and genetic disorders like sickle cell anemia and Huntington's disease.

Genes

Sections along DNA that code for proteins.

Autosomes

Chromosomes from 1 to 22 in humans; chromosomes that are not involved in determining sex.

Earwax Types

Two types: wet (sticky, yellow) and dry (flaky, pale yellow/gray).

Protein Transporter

A membrane transporter that helps move lipids across cell membranes; linked to earwax type.

ABCC11 Gene

The gene coding for the lipid transporter related to earwax type, located on chromosome 16.

Alleles

Variations of a particular gene.

G and A Alleles

In the context of earwax, the two variations for the EWax gene is the G allele and the A allele.

Genotype

The combination of alleles; the genetic makeup.

Examples of Genotypes

GG, GA, and AA are the possible genotypes for the EWax gene given there are two known alleles: G and A.

Homozygous

Having two of the same alleles (e.g., GG or AA).

Heterozygous

Having two different alleles (e.g., GA).

Dominant and Recessive Alleles

The G allele is dominant to the A allele. The G allele codes for a functioning protein, leading to wet earwax, while the A allele codes for a dysfunctional protein, leading to dry earwax.

Phenotype

The observable trait (e.g., wet or dry earwax).

Punnett Squares

A tool used to figure out the probability that a kid from a couple will have a certain genotype and therefore phenotype.

Co-dominance

Occurs when two dominant alleles are present, so the two proteins are expressed from both.

ABO Blood Group Alleles

IA, IB, and little i are the three possible alleles. IA and IB code for slightly different antigens which are proteins that sit on the red blood cells. The little i allele does not code for an active enzyme.

PTC Tasting

Artificial powder used to determine genetics based on whether person tastes it or not. Those that can taste it are tasters and it's a dominant phenotype. Those that can't taste it are non tasters and are homozygous recessive genotypes

Sickle Cell Anemia

AA genotype = normal red blood cells. SS genotype = sickle cell disease. AS genotype = mostly normal red blood cells, but sickling occurs under stress.

Pedigree

Family tree that is used by geneticists.

Huntington's Disease

A genetic disorder is the dominant allele. If someone has the dominant allele, they are affected. If homozygous recessive, they are unaffected