14.1 – Human Heredity

Human Chromosomes Karyotype – a picture of our chromosomes (each cell would have an identical looking karyotype) How is it made? Photograph cells during mitosis Cut out the chromosomes and group them together in homologous pairs

Karyotypes Male Female

Human Chromosomes Sex Chromosomes – Carry genes that determine the gender of an individual Males - XY (Y determines sex – male genes) Females – XX Often referred to as the 23rd chromosomes

Sex Determination – Punnett Square Female Male

Autosomal Chromosomes Those chromosomes not involved in sex determination Pairs 1-22 Summary Human males referred to as 46XY Human females referred to as 46XX

Pedigree Go to Section: A circle represents a female. A square represents a male. A horizontal line connecting a male and female represents a marriage. A vertical line and a bracket connect the parents to their children. A half-shaded circle or square indicates that a person is a carrier of the trait. A circle or square that is not shaded indicates that a person neither expresses the trait nor is a carrier of the trait. A completely shaded circle or square indicates that a person expresses the trait. Go to Section:

I. Rr Rr II. R_ R_ Rr Rr rr R_ III. R_ R_ R_ rr R_ Rr Rr

A B Anti A Anti B Anti A Anti B Type B Blood Type A Blood Type O Blood Type AB Blood

How is blood type inherited Type A and B are both dominant = co-dominance Type O is recessive Genotype Phenotype AB Type AB AA or AO Type A BB or BO Type B OO Type O

Rh factor Rh is a protein that also is important in blood transfusions Rh+ is dominant over Rh-

1. Mother with type A blood (AO) x Father with type B blood (BO). Genotypes ¼ AB ¼ BO ¼ AO ¼ OO A O B O AB BO AO OO Phenotypes ¼ Type AB ¼ Type B ¼ Type A ¼ Type O Mother type O blood x Father with type A. What are all the blood types their children could have? A A A O O O O AO AO AO OO Answer: Type A or Type O

Concept Map caused by include include include Albinism Section 14-1 Autosomol Disorders caused by Recessive alleles Dominant alleles Codominant alleles include include include Albinism Galactosemia Tay-Sachs disease Huntington’s disease Sickle cell disease Cystic fibrosis Phenylketonuria Achondroplasia Hypercholes- terolemia Go to Section:

Blood Groups Safe Transfusions Phenotype (Blood Type Antigen on Red Blood Cell Genotype To From Go to Section:

The Cause of Cystic Fibrosis Chromosome # 7 CFTR gene The most common allele that causes cystic fibrosis is missing 3 DNA bases. As a result, the amino acid phenylalanine is missing from the CFTR protein. Normal CFTR is a chloride ion channel in cell membranes. Abnormal CFTR cannot be transported to the cell membrane. The cells in the person’s airways are unable to transport chloride ions. As a result, the airways become clogged with a thick mucus. Go to Section: