Date: March 8, 2016 Aim #59: How can chromosomal abnormalities cause genetic disorders? HW: 1)Complete Pedigree Packet 2)Classical Genetics Quiz Thursday (p.5) and Friday (p.1 & p.7) –Review Session Wednesday morning Room 142 3)Human Phys. Unit 7b Packet due Friday (March 18 th ) Do Now: Warm-Up Notebook DateTitle of Activity Page # 3/8Nondominance103

Aim #59: How can chromosomal abnormalities cause genetic disorders?

Karyotype 1 pair of sex chromosomes 22 pairs of body chromosomes A tool used by doctors to help diagnose genetic disorders due to chromosomal abnormalities. All 46 chromosomes are arranged in homologous pairs by NUMBER

Sex Chromosomes There are TWO sex chromosomes (X and Y) and depending on which combination you receive will determine if you are a male or a female. XX- Female XY- Male

How are genetic disorders inherited in our autosomes ? Carrier: person who has the recessive allele, but does not have the disease because the second allele is normal: If both parents are carriers, what percentage of children will have the disease? C c

Great Grandparents

Pedigree Chart - A diagram that shows the presence or absence of a particular trait through each generation. c cc Cc Recessive gene on a body chromosome

aa Aa ? ?

Date: March 9, 2016 Aim #59: How can chromosomal abnormalities cause genetic disorders? HW: 1)PRACTICE!! 2)Classical Genetics Quiz Thursday (p.5) and Friday (p.1 & p.7) –Review Session Wednesday morning Room 142 3)Human Phys. Unit 7b Packet due Friday (March 18 th ) Do Now: Warm-Up Notebook DateTitle of Activity Page # 3/9Thinking Critically About Genetics 104

Tay-Sachs disease Recessive disorder Cause: gene for an enzyme that breaks down fat is mutated Symptoms: mental deficiency, blindness, death in early childhood Testing: look for enzyme Need 2 recessive alleles present to have the disease

Dominant Gene Disorders Unlike a recessive disorder where you need to inherit two recessive genes, if you inherit the one dominant gene, then you have the disease Cc cc Cccc c Cc cc

Hypercholestoremia Dominant disorder Cause: gene for receptors on the cell membrane that take cholesterol into the cell and break it down are mutated Symptoms: cholesterol in blood, heart disease Incidence: 1 in people Testing: blood test for cholesterol Normal total cholesterol levels: Children mg/dl Adults mg/dl

Sex linked genetic disorders Genes that are defective are carried on the X chromosome

Colorblindness A condition where a person cannot see certain colors, usually red and green. –Males are colorblind if they receive only one copy of the allele (c = colorblind allele) »X C Y –Females need two copies of the allele to get the trait »X C X C = colorblind female »X C X = not colorblind, it is a carrier because it can pass the trait on to offspring.

Human Genome Project Scientists studied and mapped the human genome (determined the entire nucleotide sequence of DNA). Why is this so important?

Why is it important to diagnose these diseases? TREATMENT

Summary How do chromosomal mutations lead to genetic disorders? Why might an individual with normal vision be considered to have the color blindness gene? How could the human genome project lead to the elimination of disease?