1. MUTATIONS B-4.8 Compare the consequences of mutations in body cells with those in gametes.

2. What Are Mutations? Changes in the nucleotide sequence of DNA May occur in somatic cells (aren’t passed to offspring) May occur in gametes (eggs & sperm) and be passed to offspring

3. Are Mutations Helpful or Harmful? Mutations happen regularly Mutations can result from a malfunction during the process of meiosis or from exposure to a physical or a chemical agent, a mutagen. Almost all mutations are neutral Many mutations are repaired by enzymes If a mutation is not repaired, the resulting altered chromosome or gene structure is then passed to all subsequent daughter cells of the mutant cell.

4. Are Mutations Helpful or Harmful? Some type of skin cancers and leukemia result from somatic mutations Some mutations may improve an organism’s survival (beneficial)

5. Gene Mutations If the mutant cell is a body cell (somatic cell), the daughter cells can be affected, but the mutation will not be passed to the offspring of the organism. Body cell mutations can contribute to the aging process or the development of many types of cancer. Change in the nucleotide sequence of a gene May only involve a single nucleotide May be due to copying errors, chemicals, viruses, etc.

6. Genetic Disorder Mutations If the mutant cell is a gamete (sex cell), the altered DNA will be transmitted to the embryo and may be passed to subsequent generations. Gamete cell mutations can result in genetic disorders. If the mutation affects a single gene, it is known as a gene mutation.

7. Sickle Cell Anemia Sickle cell anemia is an inherited condition in which there aren't enough healthy red blood cells to carry adequate oxygen throughout your body. Symptoms Include: Delayed Growth Frequent Infections Had-foot syndrome Anemia Pain

8. Albinism Albinism occurs when one of several genetic defects makes the body unable to produce or distribute melanin, a natural substance that gives color to your hair, skin, and iris of the eye. The defects may be passed down through families.

9. Cystic Fibrosis Cystic fibrosis affects the cells that produce mucus, sweat, and digestive juices. It causes these fluids to become thick and sticky. They then plug up tubes, ducts, and passageways. Symptoms vary and can include cough, repeated lung infections, inability to gain weight, and fatty stools.

10. Huntington’s Disease Huntington's disease is an inherited disease that causes the progressive breakdown (degeneration) of nerve cells in the brain. It typically starts in a person's 30s or 40s. Usually, Huntington's disease results in progressive movement, thinking (cognitive), and psychiatric symptoms. No cure exists, but drugs, physical therapy, and talk therapy can help manage some symptoms.

11. Chromosome Mutations May Involve: –Changing the structure of a chromosome –The loss or gain of part of a chromosome

12. Nondisjunction Failure of chromosomes to separate during meiosis Causes gamete to have too many or too few chromosomes

13. Klienfelters Syndrome Turners Syndrome A genetic condition in which a male is born with an extra copy of the X chromosome A chromosomal disorder in which a female is born with only one X chromosome