Bio 1108 Exam 8

Prophase 1: Non-Disjunction

- abnormal separation of chromosomes - if fusion of three copies, then its trisome (trisomy-21 is down syndrome, edward-18, patal syndrome-18) - if fusion of one, then its aneuploidy, xo instead of xy

incomplete dominance

- blend of traits - a white flower (AwAw) mates with red flower (ArAr) to get AwAr and a pink flower

Codominant

- both traits are present but not blended - black and white cows make a roan cow thats spotty

genetic probability

- chance of allele genotype frequency

Mendel law of segregation

- egg and sperm allele pair separate and randomly unite during fertilization - dihybrid cross 9/16, 3/16, 3/16, 1/16, ratio shows traits are independent

crossover frequency

- genes do not assort independently - higher percentage means more crossing over and farther apart on the chromosomes

Autosomal

- non sex chromosomes (1-22 pairs)

Pleiotropy

- one gene can affect multiple traits - mutation can cause more than one health problem

Meiosis

- reduction division - cell divides twice to produce gamete

Epistatis

- regulatory genes that affect nearby genes - on/off switch

Sex Linkage (X-linked traits)

-trait is one the x chromie (mostly in males) - the presence of a gene on a sex chromosome

Pedigree

circle - female square - male shaded - affected by the trait

Prophase 1: Synapsis

four homologous chromosomes come together to form tetrad

Test Cross

the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the parent genotype

sex-linked chromosomes

traits that are carried on the the x or y chromosome - sry is what makes testosterone

Recessive Allele inheritance

two unaffected parents have two children one isn't affected and one is

Prophase 1: Crossing Over

arms cross over and genes move on the chromie, this increases genetic variation

GD: Color Blind

sex link

GD: Hemophilia

sex linked

GD: Achondroplasia

Autosomal Domminant

GD: Cystic Fibrosis

Autosomal Recessive

GD: Tay-Sachs

Autosomal Recessive

GD: Huntington Disease

Autosomal Recessive- post reproductive

Dominant Allele Inheritance

affected parents have children, one is affected and one isnt

mendell law of dominance

inheritance factors, one dominant gene overshadows recessive