AP Biology Unit 5

Gregor Mendel

studied garden peas created the law of ___ and law of ___. 1890

Law of Segregation

states that there are 2 alleles per gene and alleles are separated during meiosis, each gamete receives 1 allele.

Law of Independent Assortment

Alleles of different genes sort independently if on different chromosomes. For example Flower color: P/p Seed Shape: R/r they wouldn’t effect each other, 9:3:3:1

Gene

segment of DNA that determines pigment production

Character

is a broad category of something (eye color, hair color)

trait

possible variation (blue eyes, green eyes)

true-breeding

always produces identifical to parent like PP or pp

Homozygous

either a true recessive or dominant, PP or pp,

Heterozygous

a mix dominant and recessive alleles Pp

hybridization

a cross between two pure breeds ( true-breed)

P generation

The parents (homozygous receissive and dominant)

F1 Generation

The 1st sets created (heterozygous)

F2 Generation

a ratio of 1:2:1

Punnett Square

What it is expected to look like

Phenotype

what it looks like physically

Genotype

What is the genetic make-up

Multiplication Rule

the probability of 2 or more independent events, P(A and B) = P(A) * P(B)

Addition Rule

the probability of one or two (or more) mutually exclusive events, sum of indeiviual probailities P(A or B) = P(A) + P(B)

Complete Dominance

one allele is completely masking the other allele, A- dominant a- recessive

Codominance

Both traits are fully expressed, ex. ABO, AB = AB blood, AA= A blood, BB= B blood OO= O Blood. Roan cattle, Appaloosa horse

Incomplete Dominance

The 2 alleles blend together RR*WW= 1:2:1, 2 pink, Red+ White = Pink

Snapdragon plant, Palomino (Cream + Red)

Multiple Allele

A phenotype with more that 2 alleles, Human ABO blood grou[

RH factor

a genetic trait that affects whether a blood type if positive or negative. It RH is present = positive. RH+, dominant

If a mom with RH+ blood has a RH- baby and the blood transfers mom body will create antibodies and fight the growing baby.

Rhogam

removes RH+ fetal cells before the body recognizes +, all mother in this situation would get the shot at 28 weeks.

Epistasis

“stopping gene” determines if a certain trait will be expressed at all

Pleiotropy

muliple genes to a single trains for example, a range of skin tones, height, or eye color

Norm of Reaction

Possible phenotypes, in responce to environmental conditions. someone has the genes to be tall but wasnt given proper nutrition

Multifactorial

multiple factors- multiple genes, and genetic factors, Certain genes = higher IQ, environment= access to education, prenatal, experiences

Pedigree

a way to map a particular trait within a famiy.

Tay- Sachs

causes severe neurlogical issues, seizues, paralysis die by age 4/5. Autosomal recessive,s both parents must have 1 Tay-Sachs allele.

Cystic Fibrosis

Damages lungs & Digestive system, also autosomal receissive inheritance

Phenylketonuria

Causes mental retardation, an autosomal recessive inhertiance

Huntington’s Disease

Not evident until age 35-45 (aready reproduced) Dominantly Inherited Disorder

Achondroplastic

Dwarfism, dominantly inherited disorder

Neurofibromatosis

causes learning disabilities & hyperactive, DOMINANTLY inhertied disorder

Carrier Testing:

a person of high risk of reproducing a disorder testing

Amniocentesis

fetal testing: amniotic fluid is removed to look at; takes several weeks as the fluid needs to grow

Chorine Villus Sampling

Taking part of fetal tissue and is testing, quick, days.

Ultrasound & Fetoscopy

It’s less invasive, looking for anatomical disorder s

Aneuploidy

off spring has an abnormal chromosome number

Polyploidy

Organisms inherit one or more extra sets of chromosomes

Trisomy

3 homologs instead of two for a particular chormome

Monosomy

1 homolog instead of two for a particular chromosme

Trisomy 21

Down syndrome, 2n +1 of chromosome 21

Turner’s syndrome

X, female, shorter, normal intellegance wide neck

Klinefelter’s Syndrome XXY

male, taller than average, infertile/low fertility

Jacob’s Syndrome XYY

male, delayed puberty, lower IQ,

Deletion

loss of chromosomal segment

Duplication

repeat

Translocation

moving chromosome segmet

invesion

chromosome segment rotated

mtDNA

only mother can pass it on, cardiomyopathy, epliepsy, diabetes, demntial, thyroid disease. 20-50% no disease, 50-80% mild disease, 80-100% servere disease.

Genomic Imprinting

only one allele is on, other is turned off, controlled by DNA methylation.

Prader-Willi Syndrome

when there’s a deletion or mutation in chromosome 15 deletion from paternal is silenced. short, obesity, mental retardation.

Angelman Syndrome

chromosome 15, the angelman syndroe (UBE3A) is missing or mutated. normal: maternal is active but the paternal allele is silenced due to genomic impritning. Spontanous uncontrolledable laughter, jerky movement.

Polygenetics

a disease impacts many symptoms- sickle cell disease