I. Heredity & Genetics parent to offspring oThe passing of traits from parent to offspring genes oTraits are controlled by genes

II. ALLELES FORM oONE FORM of a gene one oSex cells have one two oBody cells have two forms or ALLELES for a single gene dominant oOne may be dominant over another.

III. DOMINANT AND RECESSIVE mask oDominant will always be expressed and will “mask” recessive dominant oA recessive trait can only be expressed if there are no dominant alleles present.

oExample dominant oExample: Eyecolor—Brown color is dominant and blue is recessive.

capital lower caseDominant alleles are represented with a capital letter, recessive with a lower case letter.

7 Albinism Recessive Alleles

8 Cystic Fibrosis Recessive Alleles

9 Dwarfism Dominant Alleles

10 Sickle Cell Disease Recessive Alleles

IV. GREGOR MENDEL father oFirst known geneticist and “father of genetics” 1822 oWas an Austrian monk and was born in 1822 pea oDid most of his genetic studies on pea plants

oHe performed cross- pollination shapepeascolor seeds height position oMendel worked with shape of peas, color and shape of seeds, plant height, flower position and flower color.

V. PROBABILITY chance oHelps predict the chance that something will happen 50% oExample: the probability of throwing heads or tails on a coin is 50% (1/2 chances) accurate oYour predictions become more accurate with the more trials you run!

Why is it that if a couple has 2 children, they don’t always have one boy and one girl? 2 is a really small trial #…so won’t always “see” the ratio!

VI. Using a Punnett Square oUsed to predict probability of traits otrait is givenTWO letters, one for each allele.

same o“Purebred” =two alleles the same, BB or bb. otwo different alleles = “heterozygous”(hybrid). Bb genotype oThe alleles present = genotype. Ex. BB, Bb, or bb.

PHENOTYPE oThe PHYSICAL trait =PHENOTYPE. oFor instance, Blue or Brown Eyes.

Steps for using the Punnett square: (genotype) 1)One parent’s alleles (genotype) go on the top 2)The other parent’s alleles go down the side. 3)You fill in the squares like a multiplication table.

Incomplete dominance Heterozygous expresses a different phenotype from either homozygous. Usually intermediate between the two. C R C R = Red C W C W = White C R C W = Pink

Multiple alleles - Blood type 3 alleles, codominance A,B,o

4 blood types from 3 alleles AA or Ao= type A BB or Bo= type B AB = type AB oo = type O

DIHYBRID crosses 2 traits Heterozygous parents

Polygenic inheritance = many genes for one character.

SEX-LINKED and SEX INFLUENCED TRAITS

SEX CHROMOSOMES CAN CARRY OTHER GENES TOO = ___________________ SEX LINKED TRAITS

SEX LINKED TRAITS show up in different % in males and females because they move with the sex chromosomes

Sex chromosomes can carry other genes Y-LINKED GENES: Genes carried on Y chromosome EX: Hairy pinna _________genes only show up in _______ Y linkedmales.

Sex chromosomes can carry other genes X-LINKED GENES: Genes carried on the X chromosome EX: _____________ _____________ _________________________ Hemophilia Colorblindness Duchenne Muscular Dystrophy

31 missing protein for normal blood clotting Hemophilia

32 1 in 10 males in the US. Color Blindness

females

34

35

36 Duschenne Muscular dystrophy progressive weakening and loss of skeletal muscles

SEX INFLUENCED TRAITS Genes ___________ on sex chromosomes BUT affected by ____________ of individual with gene not carried sex hormones

How are genes passed on over generations?

PEDIGREE CHART Normal Male = Normal Female = Has trait = Carrier =

CARRIER Individual with one copy of a recessive autosomal allele Carriers DON’T SHOW the trait themselves but can pass it on to their offspring NORMAL DEFECTIVE

Prenatal Diagnosis Amniocentesis Chorionic villus sampling Fetoscopy

Prenatal Diagnosis Amniocentesis