KEY CONCEPT Mutations are changes in DNA that may or may not affect phenotype.

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KEY CONCEPT Mutations are changes in DNA that
may or may not affect phenotype.
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Mutations

• Caused by errors in
• Replication, transcription, cell division, or by
  external factors
• Germ-cell mutation occurs in a gamete
• Do not affect the individual but may be passed on
  to offspring
• Somatic mutation occurs in a body cell
• Will affect the individual but are not passed on
  to offspring

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Lethal Mutations

• Cause death, often before birth

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Some mutations affect a single gene

• A point mutation - substitutes one nucleotide for
  another.
• Or adds or removes a single nucleotide

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• Frame Shift Mutation
• Deletion addition point mutation - causes the
  remaining codons to be incorrectly grouped

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Chromosome Mutations

• Deletion loss of a piece of a chromosome due to
  chromosomal breakage
• Inversion chromosomal segment breaks off and
  then reattaches in reverse order to the same
  chromosome
• Translocation chromosome piece breaks off and
  reattaches to another non-homologous chromosome

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Nondisjunction failure of homologous
chromosomes to separate properly during meiosis

• One gamete would have an extra chromosome
• when fertilized would have 3 copies of chromosome
  
• trisomy.
• One gamete would have one less chromosome
• when fertilized would have 1 copy of chromosome
• monosomy

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7.4 Human Genetics and Pedigrees
KEY CONCEPT A combination of methods is used to
study human genetics.
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• Pedigree family record that shows how a trait
  is inherited over several generations

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Pedigrees

• Carrier individual with one copy of a recessive
  allele
• Usually do not express the trait but can pass it
  along to offspring

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A pedigree is a chart for tracing genes in a
family.
7.4 Human Genetics and Pedigrees

• Phenotypes are used to infer genotypes on a
  pedigree.

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7.4 Human Genetics and Pedigrees

• Karyotypes can show changes in chromosomes.

• deletion of part of a chromosome or loss of a
  chromosome
• large changes in chromosomes
• extra chromosomes or duplication of part of a
  chromosome

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Detecting Human Genetic Disorders

• Genetic screening examination of a persons
  genetic makeup
• Genetic counseling medical guidance that
  informs about possible problems that could affect
  their offspring
• Prenatal testing
• Amniocentesis removes a small amount of
  amniotic fluid between the 14th
• and 16th week of pregnancy

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• Chorionic villi sampling physician obtains a
  sample of the chorionic villi tissue that grows
  between the mothers uterus and the placenta,
  between the 8th and 10th week of pregnancy

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5.3 Regulation of Cell Cycle
KEY CONCEPTCell cycle regulation is necessary
for healthy growth.
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Mutations can be caused by several factors.
5.3 Regulation of Cell Cycle

• Replication errors can cause mutations.
• Mutagens, such as UV ray and chemicals, can cause
  mutations.
• Some cancer drugs use mutagenic properties to
  kill cancer cells.

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8.3 Cancer
5.3 Regulation of Cell Cycle

• Tumor abnormal group of cells that result from
  uncontrolled, abnormal cell division

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5.3 Regulation of Cell Cycle

• Benign tumors remain clustered and can be
  removed.
• Malignant - uncontrolled dividing cells invade
  and destroy healthy tissues elsewhere in the body
  
• Metastasize - spread of cancer cells beyond their
  original site

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Kinds of Cancer based on types of tissue that
affect
5.3 Regulation of Cell Cycle

• Carcinomas grow in the skin and tissues that
  line organs. Ex lung cancer breast cancer
• Sarcomas grow in bone and muscle tissue
• Lymphomas solid tumors that grow in the tissues
  that form blood cells
• Leukemia tumors that form in blood-forming
  tissue over production of white blood cells

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Causes of Cancer
5.3 Regulation of Cell Cycle

• Carcinogen substance that increases the risk of
  developing cancer Ex tobacco, asbestos,
  X-rays, or UV rays from sun
• Mutagen cause mutations to occur within a cell
  that leads to cancer

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5.3 Regulation of Cell Cycle

• Standard cancer treatments typically kill both
  cancerous and healthy cells.

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Oncogenes gene that causes cancer
5.3 Regulation of Cell Cycle

• Proto-oncogene normal gene that control cells
  growth. When mutated ? oncogene
• Tumor-suppressor gene code for proteins to
  prevent uncontrolled cell division. When mutated
  ? cancer

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Viruses Cancer
5.3 Regulation of Cell Cycle

• Viruses can stimulate uncontrolled cell division
• Cause mutations in proto-oncogenes tumor
  suppressor genes

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Cancer Prevention
5.3 Regulation of Cell Cycle

• Diet high in fiber and low in fat
• Fruits vegetables are high in fiber
• Vitamins minerals carotenoids, vitamins A, C,
  and E, and calcium
• Daily exercise
• And lowering exposure to carcinogens (tobacco, UV
  rays)

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Extra Credit

• Millions of dollars are spent each year on cancer
  research.
• Contact an oncologist in a cancer treatment
  center.
• Conduct an interview, prepare a paper, and create
  a visual to show the new treatments that have
  been developed in the past 10 years