WARM-UP: 5 MINUTES 1. What is the difference between incomplete dominance and codominance? Give an example for each. 2. List the genotypes and phenotypes if a woman who has heterozygous Type A blood marries and has kids with someone who is heterozygous Type B. (Punnett) 3. Is it possible for the dad to pass on an X-linked trait to his son? Why or why not?

KARYOTYPE: SHOWS A PERSON’S CHROMOSOMES COPYRIGHT CMASSENGALE 2

AUTOSOMES VS. SEX CHROMOSOMES Autosomes = the body chromosomes; #1-22 Sex chromosomes = the sex chromosomes; #23 only

MALE OF FEMALE?

COPYRIGHT CMASSENGALE 5 This is a normal karyotype. How many pairs of chromosomes are there? How many chromosomes total? Is this person a male or female? How can you tell?

WHAT A KARYOTYPE CAN SHOW YOU… COPYRIGHT CMASSENGALE 6 1. If the person is normal (without disorders) 2. If they have a disorder* ex. Trisomy/nondisjunction 3. The gender (male or female)

NON-DISJUNCTION/TRISOMY COPYRIGHT CMASSENGALE 7 What is it? Non-disjunction refers to when the homologous chromosomes or sister chromatids don’t separate properly during meiosis Results in cells with abnormal chromosome amounts (aneuploidy) Ex. Trisomy = three chromosomes Down’s Syndrome = Trisomy 21

DOWN’S SYNDROME COPYRIGHT CMASSENGALE 8

1. MALE OR FEMALE? 2. IS THIS PERSON NORMAL OR DO THEY HAVE A DISORDER? IF SO, WHERE?

PEDIGREE CHART COPYRIGHT CMASSENGALE 10 Is a map of a family’s relationships It can be used to trace a disorder or interesting trait through a family

KEY:

PRACTICE: 1. WHAT ARE A AND B? 2. HOW MANY KIDS DID THEY HAVE? 3. WHAT IS D? AB C D

FOR THE BELOW EXAMPLE WRITE: H = FOR HEALTHY (INDIVIDUALS WITHOUT THE TRAIT) C = FOR CARRIERS (INDIVIDUALS THAT CARRY THE TRAIT BUT DON’T SHOW IT) I = FOR INFECTED

IS IT SEX-LINKED OR AUTOSOMAL? 1.If there is a much larger number of males than females who are affected, it is a sex-linked disorder. 2.If there is a 50/50 ratio between males and females who are affected, it is a autosomal disorder.

PRACTICE EXAMPLES Does this pedigree show a Sex-linked or Autosomal disorder? (remember: compare males to females affected) Answer: Sex-Linked disorder much larger number of males are affected Slide # 12

PRACTICE EXAMPLES Does this pedigree show a Sex-linked or Autosomal disorder? Answer: Autosomal disorder 50/50 ratio between males and females Slide # 13

PRACTICE EXAMPLES Does this pedigree show a Sex-linked or Autosomal disorder? Answer: Autosomal disorder 50/50 ratio between males and females Slide # 15

PRACTICE