Karyotype and Pedigree review

Karyotype

A display of the chromosome pairs of a cell arranged by size and shape.

Sex Chromosomes

Chromosomes that determine the sex of an organism (X or Y in humans)

Autosomes

non-sex chromosomes

Genetic Disorder

An abnormal condition that a person inherits through genes or chromosomes

Trisomy

3 copies of a chromosome

Monosomy

missing a chromosome

Down Syndrome

a condition of intellectual disability and associated physical disorders caused by an extra copy of chromosome 21.

Turner Syndrome

A chromosomal disorder in females in which either an X chromosome is missing

Nondisjunction

Error in meiosis in which homologous chromosomes fail to separate.

Pedigree

A diagram that shows the occurrence of a genetic trait in several generations of a family.

Homozygous

Having two identical alleles for a particular gene

Heterozygous

having two different alleles for a trait

Carrier

A person whose genotype includes a gene that is not expressed in the phenotype.

Dominant

Describes a trait that covers over

Recessive

Describes a trait that is covered over

chromosomal disorders

disorders that result when too many or too few chromosomes

Genome

all of an organism's genetic material

sex chromosomes

Chromosomes that determine the sex of an individual

Inheritance

The process in which genetic material is passed from parents to their offspring.

Mutation

A change in a gene or chromosome.

generation

A group of people born around the same time

law of segregation

the law stating that members of each pair of genes separate or segregate when gametes are formed

law of independent assortment

the law that describes genes encoding for different traits separating from one another independently during the formation of gametes

product rule

the rule that states that the probability of 2 or more independent events occurring together is the product of the individual probabilities of each event occurring alone

complete dominance

no mixing of colors of fur, hair, etc

incomplete dominance

mixing of the colors, neither trait is dominant

codomiance

they mix together entirely, both traits are shown in the phenotype, BW, WW, BB

autosome

chromosome that isn’t a sex cell

sex linked trait

when the trait is controlled by a gene found on one of the sex chromosomes, most sex linked traits are carried on the X chromosome (the dad), color-blindness is carried by the woman but usually found on the son

polygenic inheritance

a process in which two or more genes affect the same characteristic

karyotype

a line on the chromosome that identifies itself as a different trait

down syndrome

extra chromosome

klinefelter’s syndrome

a man with XXY (an extra X chromosome, meaning he probably makes more estrogen than testosterone)

turner syndrome

a genetic disorder resulting from a missing ex chromosome, female has only one X chromosome

restriction enzyme

the little line on the DNA fingerprinting machine from the forensics video

gel electrophoresis

basically making the DNA more visible

determine if the trait in the pedigree is dom or recessive

step 1

determine the genotypes of the individuals

step 2

use the genotypes to create a punnett square to solve the pedigree

step 3 and final step of solving a pedigree

monohybrid cross

a genetic cross involving individuals both heterozygous (Tt) for one trait

dihybrid cross

a genetic cross involving individuals both heterozygous for 2 traits, requires a larger punnett square, meaning 4 of each parent