Bio Unit 9

before modern genetics what was the common belief

blended inheritance

what is blended inheritance

tall+short=medium

who was Gregor Mendel

father of genetics

a bad priest

moved to Abbey Garden

disproved blended inheritance

character

heritable feature that varies among individuals

traits

varients of a character

what did Mendel do

crossed pea plants and traced traits from generation to generation

what did Mendel hypothesize

that there are alternate versions of genes (alleles)

what are genes

units that determine heritable traits

what are alleles

different versions of genes

hereditary

transmission of traits from one generation to the next

what comes after the parent (P) generation

F1→F2→etc

what were mendel’s 2 main ideas

we have different versions of genes (aka alleles) and each organism will have 2 alleles (one per parent)

homozygous

two identical alleles for a gene (AA, aa)

heterozygous

two different alleles for a gene (Aa)

dominant allele

if 2 alleles of an inherited pair different and one determines appearance

recessive allele

no noticeable effect appearance (needs 2 recessive to be said color)

law of segregation

a sperm or egg carries only one allele for each inherited character because allele pairs separate from each other during production of gametes

genotype

alleles an individual has (AA, Aa, aa)

phenotype

physical traits (brown eyes, blue eyes)

monohybrid cross

looking at one trait

dihybrid cross

looking at 2 traits

carrier

heterozygous (have one of each)

testcross

a mating between individual of unknown genotype and a homozygous recessive individual

types of genetics screenign

carrier screening, fetal testing, fetal imaging, newborn screening (provides information for reproductive decisions, ethical dilemmas)

incomplete dominance

when an appearance falls between the genotypes of the parents

complete dominance

mendels idea (one or the other will show)

ABO blood groups

a phenotype the is controlled by 3 alleles but can make 4 diff phenotypes

codominant (def and ex)

both alleles are expressed in a heterozygous individual (I^a I^b blood type AB)

pleiotropy

when 1 gene influences multiple characters

ploygenic inheritance

when one phenotypic trait is effected by many genes (ex height epistasis)

blond and brown hair

brown dominant

blue and brown eyes

brown dominant

cleft chin and non cleft chin

cleft dominant

freckles or no freckles

freckles dominant

huntington’s disease

autosomal dominant

degeneration of the nervous system

polydactyly

autosomal dominant

extra fingers, toes, or both

progeria

autosomal dominant

drastic premature aging

albinism

autosomal recessive
absence of pigmentation

sickle-cell amemia

autosomal recessive

anemia, pain, swelling, frequent infections

cystic fibrosis

autosomal recessive

chronic lung infections, difficultly breathing

red-green colorblindness

X-linked recessive

inability to distinguish red from green

hemophila

X-linked recessive

impaired blood clotting

muscular dystrophy

X-linked recessive

progressive loss of muscle function

down syndrome

extra chromosome 21

mental impairment, heart defects

klinefelter syndrome

XXY (1 in 500 males)

sterility, mental impairment, tall and overweight

XXX syndrome

XXX (1 in 1000 females)

minimal changes, sometimes mild mental impairment

what is the gene for the letter of blood

ABO gene

what is the gene for the +- of blood

Rh gene

what are the 2 main things about blood

multi-allele system and codominance

ABO dominance

A dom to O

B dom to O

A and B codomiannt

O recessive

what does it mean if a person is - -

their blood type is negative and they don;t have the Rh gene

what is the genotype and phenotype of a person with A positive blood

AB negative

g - AO+- or AO++ p-A+

g- AB- - p-AB-

what is fetal hemolytic syndrome

when a mom who is Rh neg (- -) and a dad who is Rh pos (++ or +-) have a child

do the [unnet square in your head and they will most likely have a child who is +-

not problematic for the first pregnancy why? your body will not start making anti “ anything “ (whatever you are not in this case the mom will not make anti +) until it is met with that (mom is met with the first baby’s positive blood in the first pregnancy and after starts making antibodies for it

so the next pregnancy mom will “attack” baby in childbirth because she is making antibodies for + blood

what does a pedigree do

show a trait through family generation

what is a male and female represented as

male - square female - circle

what does it mean if it is shaded

that person has that trait that is being followed

if it is a dominant trait what will the pedigree look like

shaded parents with at least one kid who is not shaded

if it is recessive what will that pedigree look like

2 unshaded parents with at least one shaded kid

if it is a dominant pedigree what can you automatically assume

the shaded ppl have at least one dominant allele and the unshaded are homozygous recessive

if it is recessive what can you automatically assume

any shaded ppl are homozygous recessive and those whoa re unshaded have at least one dominant allele

how can you guess if a trait is X-linked

mostly males affected

why are mostly males affected by X-linked traits

they have one X meaning they will or wont have that trait depending on that one X

females have 2 and can be a carrier

tongue rolling

ablilty to roll tongue is dominant

how would u show that chances of a man and women having 17 kids (man cleft chin and roll tongue)(woman no roll no cleft)(all kids no roll and no cleft)

take your ratio 4:16 —> put it into the divison format 4/16 —> do the math (0.25)—> an put that to the power of kids (0.25^17=5.82×10^-11) those r the chances of that occuring (aka very low)

when talking about if a trait is recessive or dominant DONT FORGET TO DO WHAT

clarify if it is autosomal or X-linked

are there carriers of dominant traits recessive traits or both

ONLY RECESSIVE traits can have a carrier