BIOL 190 Genetics Lecture Notes Flashcards

Flashcards covering definitions and concepts of genetics, Mendelian laws, inheritance patterns, and X-linked disorders from the BIOL 190 lecture.

Phenotype

The physical Appearance or characteristics that you observe in an individual such as eye color or hair.

Genotype

The Code for phenotypes; the Collection of individual's genes or the genetic make up of the cell.

Allele

A Variation of the gene such as black or redhair, tall or short height, green or brown eyes, etc.

Dominant allele

An allele that will Determine the phenotype if present and has the most power over any other allele; described with Capital letters like $T$, $A$, $G$, $S$, etc.

Recessive allele

An allele that can only be expressed when it is pained with another recessive Allete and is ignored when there is a dominant allete present; described with lowercase letters like $t$, $a$, $g$, $s$, etc.

Homozygous dominant

A genotype where an individual has two alleles that are both Dominant, for example $TT$ or $SS$ or $GG$.

Heterozygous

A genotype where an individual has one dominant and one Recessive Allele, for example $Tt$ or $Ss$ or $Gg$.

Homozygous recessive

A genotype where an individual has two recessive alleles, for example $tt$ or $ss$ or $gg$.

Gregor Mendel

The "Father of Genetics" who discovered 2 laws: Law of Segregation and Law of Indepent Assortment.

P

The parent generation.

F1

The first generation of offspring.

F2

The second generation of offspring.

Law of Segregation

The principle that offspring will end up with only $2$ Alleles in their genotype (instead of $4$) and the cycle can continue.

Law of Independent Assortment

The principle that parental chromosomes have an equal and random chance of Separating into gametes during melosis, leading to greater Genetic diversity.

Punnett squares

A grid that allows you to predict the gentype of the next generation offspring based on the Parental genotypes.

Genotypic ratio

The number of offspring with the Same genotype; for example, a ratio of $1:2:1$ ($1 \text{ FF}: 2 \text{ Ff}: 1 \text{ ff}$).

Phenotypic ratio

The number of offspring with the same outward appearance; for example, a ratio of $3:1$ ($3$ with freckles and $1$ with no freckles).

Autosomal recessive disorder

A disorder coded for on the autosomes (not the sex chromosomes) where individuals must be homozygous recessive to have the disorder.

Autosomal dominant disorder

A disorder where any individual with a dominant allele (homozygous dominant or heterozygous) will have the disorder.

Incomplete dominance

Occurs when the Heterozygote is Intermediate between the $2$ Homozgotes, such as wavy hair ($CS$) from curly ($CC$) and straight ($SS$) parents.

Codominance

Occurs when the Alleles are equally expressed in a heterozgote, such as Blood type $A$ ($AA$) and type $B$ ($BB$) resulting in $AB$.

Multiple allele inheritance

When the phenotype is coded for multiple patterns of inheritance, involving both Simple dominant/recessive and codominance.

Glycoproteins

Proteins with polysaccharides attached located on the red blood cell exterior surface to help the immune system identify cells.

Type O blood

A blood type characterized by having No protien on the cell membrane.

X-linked inheritance

Inheritance where the Allele is carried on the $x$ chromosome.

Y-linked inheritance

Inheritance where the Altele is carried on the $y$ chromosome.

Color blindness

An X-linked recessive disorder; for example, a male who inherits the allele on his $x$ chromosome ($XY$) will be color blind.

Muscular dystrophy

An X-linked recessive disorder involving the wasting of muscles and Death by age $20$.

Fragile X syndrome

An X-linked recessive disorder that is the Most common cause of inherited mental impariment.

Hemophilia

An X-linked recessive disorder where the blood Clots very slow or not at all.

Pedigrees

Tools used to help identify genetic traits passed through Families.

Pedigree: Squares

The symbol used to represent males in a pedigree.

Pedigree: Circles

The symbol used to represent females in a pedigree.

Pedigree: White shape

The representation in a pedigree for individuals who Do Not have the Disease.

Pedigree: Colored shape

The representation in a pedigree for individuals who Do have the Disease.