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Genetic Disorders, Blood Typing, and Genetic Engineering. Genetic Disorder. Is an abnormal condition that a person inherits through genes and chromosomes Two causes: Mutations in DNA Changes in overall structure or numbers of chromosomes. Prenatal Diagnosis Amniocentesis.
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Genetic Disorder • Is an abnormal condition that a person inherits through genes and chromosomes • Two causes: • Mutations in DNA • Changes in overall structure or numbers of chromosomes
Prenatal DiagnosisAmniocentesis • A small sample of the amniotic fluid surrounding the baby is removed using a syringe. • The fluid contains skin cells from the baby. • The skin cells are grown in the lab.
The chromosomes from the cells are magnified under a microscope and a picture is taken. • The chromosomes are cut out and arranged in homologous pairs in decreasing size order. • This is called a karyotype.
Down Syndrome (Trisomy 21) • Extra chromosome 21 in every cell of the body • Causes mental retardation, heart defects
As a woman gets older, her chances of having a baby with a chromosome abnormality increases ***remember, a woman is born with all of her egg cells, but meiosis is not yet complete (egg development stops in prophase I until the follicle matures prior to ovulation)
Turner Syndrome female born with only one X chromosome Characteristics • short stature • ovaries do not develop (infertile) • cardiovascular problems • kidney and thyroid problems • skeletal disorders such as scoliosis
Klinefelter Syndrome47,XXY Characteristics • Infertility (cannot produce a lot of sperm) • Abnormal body proportions (long legs, short trunk, shoulder equal to hip size) • Abnormally large breasts (gynecomastia)
Cystic Fibrosis • Genetic disorder in which the body produces abnormally thick mucus in the lungs and intestines • Caused by a recessive allele that is a result of a mutation in which 3 bases are deleted from a DNA molecule
Sickle Cell Disease • Affects hemoglobin, which is a protein that carries oxygen • When oxygen levels are low the blood cells have a sickle shape instead of the normal round shape • These sickle shaped blood cells clog blood vessels and carry less oxygen • Autosomal recessive
How to Manage Genetic Disorders • Karyotypes – used to detect chromosomal disorders such as down syndrome • Genetic counseling -Assess the risk of a genetic disorder by researching a family's history and evaluating medical records.
Blood Typingcontrolled by multiple alleles • Human trait controlled by more than one allele is said to have multiple alleles • Even though a gene may have multiple alleles, a person can only carry 2 of those alleles because we have only 2 chromosomes • Four major blood types: A, B, AB, AND O
Blood types A and B and AB • Codominant • Alleles for blood type A is AA • Alleles for blood type B is BB • a cross between blood type A and blood type B • Results in a person with type AB blood
Blood Type O TYPE O BLOOD • Allele for blood type O is recessive • Only way to get blood type O is to have both parents with blood type O
Advances in Genetics • Human Genome Project • DNA fingerprinting • Genetic engineering
Human Genome Project (HGP) • Genome is all the DNA in one cell of an organism • HGP- is the code that is 6 billion letters long • Main goal of the project is to identify the DNA sequence of every gene in the human genome • We have at least 30,000 genes • Average gene has about 3000 bases
DNA Fingerprinting • DNA is broken down into small fragments • Selected fragments rare used to produce a pattern called: DNA FINGERPRINT • Except for identical twins no 2 people have the same DNA fingerprint
Genetic Engineering • Genes from one organism are transferred into DNA of another • Used to produce medicine and crops resistant to diseases • Insulin (used by diabetics) is produced by genetically engineered bacteria
Genetic Engineering of Organisms Genes are inserted into animals such as cows to produce the human clotting protein needed by people with hemophilia Spider Goat