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

2. 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.

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

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

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

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

7. Notes
Chromosomes
1. ____________ exists in pairs.

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

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

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

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

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

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

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

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

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

18. 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.

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

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

21. 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.

22. 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

23. 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

24. 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.

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

27. 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.

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

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

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

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

32. 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.

33. 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.

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

35. 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

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

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

38. 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

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

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

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