5/23/16 Date:5/23/16Topic:Genetics Day 3Page # ___ In chinchillas, “standard” coat color (silver/grey) is dominant to “beige” coat color (light tan). If you breed a male chinchilla who is heterozygous for standard to a beige female chinchilla, what percent of their offspring will be standard colored? Male Offspring?? Female Get out your HW!!!

Today in Room 326… HW: Sex-linked questions CONTENT OBJ: SW complete punnet square problems for blood type and sex linked inheritance LANG. OBJ: SW read blood type handout, define genetics vocab in writing, discuss in pairs ANNOUNCEMENTS: Science Fair!!! AGENDA: Review Inheritance Patterns (15 min) Blood Types Reading (10 min) Blood Types Notes (10 min) Blood Type Practice (15 min) Sex Linked Notes (15 min) Sex Linked Practice (15 min) Date:5/23/16Topic:Genetics Day 3Page # ___

Review Incomplete Dominance Codominance

What type of inheritance pattern is this?

Inheritance Patterns* Complete Dominance (“regular”) Incomplete Dominance (“blend”) Codominance (“both present”) Polygenic Inheritance: Trait is controlled by multiple genes Multiple Allele Inheritance: Trait is controlled by multiple alleles (more than 2 “letters”)

Polygenic Inheritance Some phenotypes are determined by additive effects of 2 or more genes on a single chromosome Phenotypes on a continuum Examples***: Skin color HeightWeightIntelligenceBehaviors

Multiple Alleles Inheritance = When there are more than the typical 2 alleles that impact the phenotype (trait) Example = Blood Type*

Blood Type? Which type do you think you are, and why? What do you know about blood typing and its importance? How can you find out your type? Have you ever gotten your blood drawn? What blood type are you?? Read article and find out!

Antigen: Any substance that causes your immune system to produce antibodies against it Antigen?

Genotype vs. Phenotype

Blood Type* -Type A and B are Codominant -Type O is recessive Phenotype:Genotype:

Punnet Square Practice Mom: AB Dad: B hetero % children w/ B? Answer: ________

Punnet Square Practice John’s blood type is AB. His wife blood type is BO. They have a child with blood type O. Do you suspect foul play? Use a Punnett square to explain the answer.

Who could NOT be the father?

ABO Practice Worksheet May see little “i” with the letter above it…

Sex-Linked Inheritance* Now, sex matters.

Sex-Linked Traits When genes are on sex chromosomes instead of autosomal (body) chromosomes* First discovered by T.H. Morgan at Columbia U. Drosphilia (fly) breeding Did many tests to determine how sex-linked traits work

Sex Determination*

Where are the sex chromosomes??? Give me a number of an autosomal chromosome…

Genetics of Sex In humans & other mammals, there are 2 sex chromosomes: X & Y 2 X chromosomes = XX = female Gene redundancy 1 X and 1 Y chromosome = XY male No redundancy

Genes on Sex Chromosomes Y chromosome Few genes other than SRY gene Sex determining region Turns on genes for production of male hormones X chromosome Other genes/traits beyond sex determination Hemophilia Duchenne muscular dystrophy Color-blindness

Punnet Square Practice If a man with hemophilia marries a homozygous normal woman, what is the probability of them having a hemophiliac child? What’s a “carrier” mean???

Class Babies Let’s give the guys a disease on their X chromosome… How many girls do we have?? How many girls do we have?? The girls are CLEAN. They are not affected, and are not carriers. Guys, pick a girl and have her babies. What percent of your kids will be affected/carriers? And what gender?

Volunteer to explain example?

Sex-Linked Facts A woman has 2 X’s, so even if she has one affected X, she can still be “normal” A man has only one X, so if his X is affected, he will express the disease An affected man can never pass on the trait to his son. Why? An affected mom and unaffected man can never have an affected daughter. Why?

X-Linked Practice Problems Worksheet