Chapter 4 Modern Genetics Section 1 Human Inheritance Cells and Heredity Chapter 4 Modern Genetics Section 1 Human Inheritance

Section 1 Human Inheritance: Objectives To explain what multiple alleles are. To explain why some human traits show a large variety of phenotypes. To explain how environmental factors can alter the effects of a gene. To explain what determines sex and why some sex linked traits are more common in males than in females. To describe how geneticists use pedigrees.

Section 1 Human Genetics Vocab 1. multiple alleles Three or more forms of a gene that code for a single trait.

2. sex-linked gene A gene that is carried on the X or Y chromosome

3. carrier A person who has one recessive allele for a trait and one dominant allele, but does not have the trait.

4. pedigree A chart or “family tree” that tracks which members of a family have a particular trait.

Notes Chromosomes 1. ____________ exists in pairs.

2. Two traits controlled by many genes are: height skin color

3. Three environmental factors that can effect height are: B C Lack of protein Lack of minerals Lack of vitamins

4. There are __________ chromosomes in each body cell. 23 pairs of 4. There are __________ chromosomes in each body cell.

XY 5. Males have the ______ combination of chromosomes, while females have the _______ combination XX

6. The _________ determines the gender of the offspring. sperm 6. The _________ determines the gender of the offspring.

Males 7. ________ are more likely to have a sex-linked trait that is controlled by a ______________ allele. recessive

Chapter 4 Modern Genetics Section 2 Human Genetic Disorders Cells and Heredity Chapter 4 Modern Genetics Section 2 Human Genetic Disorders

Section 2 Human Genetic Disorders: Objectives To describe the causes and symptoms of four human genetic disorders To explain how genetic disorders are diagnosed.

Vocab 5. genetic disorder An abnormal condition that a person inherits through genes or chromosomes.

6. amniocentesis A technique by which a small amount of the fluid that surrounds a developing baby is removed; the fluid is analyzed to determine whether the baby will have a genetic disorder.

7. karyotype A picture of all the chromosomes in a cell arranged in pairs.

Notes Genetic Disorders 1. ______________________ are caused by _____________________, or changes in a person’s ______________. mutations DNA

2. Describe each order and its cause A. Cystic Fibrosis Affect- Cause- Causes think mucus to build up in a person’s lungs and intestines A mutation that is carried on a recessive allele.

B. Sickle-Cell Affect- Sickle shaped red blood cells that Cause- Sickle shaped red blood cells that can not carry as much oxygen as normal blood cells A mutation that affects the production of hemoglobin, a protein in red blood cells that carries oxygen

C. Hemophilia Affect- A disorder in which a person’s blood Cause- A disorder in which a person’s blood clots very slowly or not at all People with the disorder do not produce one of the proteins needed for normal blood clotting

D. Down Syndrome Affect- Cause- A distinctive physical appearance, some degree of mental retardation, heart defects. Many people with down syndrome lead full lives. A person’s cells have an extra copy of chromosome 21.

Chapter 4 Modern Genetics Section 3 Advances in Genetics Cells and Heredity Chapter 4 Modern Genetics Section 3 Advances in Genetics

Section 3 Advances in Genetics: Objectives To describe three ways in which people have developed organisms with desired traits. To explain how DNA fingerprinting is used To state the goal of the Human Genome Project.

Vocab 8. Selective breeding The process of selecting a few organisms with desired traits to serve as parents of the next generation.

9. Inbreeding A selective breeding method in which two individuals with identical or similar sets of alleles are crossed.

10. Hybridization A selective breeding method in which two genetically different individuals are crossed.

11. Clone An organism that is genetically identical to the organism from which it was produced.

12. Genetic engineering The transfer of a gene from the DNA of one organism into another organism, in order to produce an organism with desired traits.

13. Gene therapy The insertion of working copies of a gene into the cells of a person with a genetic disorder in an attempt to correct the disorder.

14. Genome All of the DNA in one cell of an organism.

Notes 1. Two examples of selective breeding A. B. Dairy cows are bred to produce larger quantities of milk Varieties of fruits and vegetables that are bred to resist diseases

2. Two examples of inbreeding Some purebred horses Purebred dogs, such as Labrador retrievers and German sheperds

3. One problem with inbreeding is: Increases the chances of inheriting alleles that lead to genetic disorders.

4. Two examples of hybridization Crossing corn that produces many kernels With corn that is resistant to diseases A mule coming from the cross of a mare and a donkey. The mule has the courage, stamina, and surefootedness of the donkey with the strength of a horse

5. A common example of cloning is *To make a “cutting” from a plant. The cutting can grow into a new plant

hair 6. DNA samples from _______, ______, and _____ can be used to identify a person. skin blood

7. No two people, except _______________ have the same DNA. Identical twins