Presentation is loading. Please wait.

Presentation is loading. Please wait.

Cancer & Mutations Powerpoint

Similar presentations

Presentation on theme: "Cancer & Mutations Powerpoint"— Presentation transcript:

1 Cancer & Mutations Powerpoint
SB2. Students will analyze how biological traits are passed on to successive generations. d. Describe the relationships between changes in DNA and potential appearance of new traits including Alterations during replication. Insertions Deletions Substitutions Mutagenic factors that can alter DNA. High energy radiation (x-rays and ultraviolet) Chemical

2 What is Cancer? Kinds of cancer Cancer - Uncontrolled cell growth
*Cells only grow during the correct conditions *Limited by space, nutrients, chemicals, etc. Kinds of cancer Carcinomas – grow in the skin and he tissues that line the organs of the body Ex. lung and breast cancer Sarcomas – grow in bone and muscle tissue Lymphomas – solid tumors that grow in the tissues that form blood cells Ex. leukemia, the uncontrolled production of white blood cells

3 Tumor Tumor - mass of cell due to uncontrolled cell growth
Benign - an abnormal, non-threatening cell mass Malignant - uncontrolled cell mass that continually divides and multiplies Metastasis - spread of cancer cells beyond original site

4 Cancer Cancer cells, unlike normal cells, continually grow even when the region is over crowded. The cell does not recognize the message to stop dividing. Normal cells will not go through cell division unless they are attached to neighboring cells. The cancer cells continue to grow and this leads to the spread of the problem throughout the body, also called metastasis.

5 What causes cancer? Growth factors - proteins that ensure the events of the cell cycle progress in proper order. Ex Cyclins and CDKs Mutations in these proteins result in uncontrolled cell growth.

6 Cancer causes Carcinogens - any substance that increases the risk of cancer Ex. Tobacco, asbestos, and radiation such as X-ray, and UV light from sun.

7 Genes related to cancer
Oncogenes – gene that causes cancer or other uncontrolled cell proliferation Proto-Oncogenes – gene that codes for proteins involved in the cell cycle Tumor-suppressor genes – code for proteins that prevent the uncontrolled rate of cell division

8 Can Cancer Occur Organisms other than humans?
Discussion Can Cancer Occur Organisms other than humans? Yes No

9 What is a mutation? Mutation – a change in the DNA of an organism
Germ-line mutation – occur in gametes of organism Passed on to offspring, do not affect the organism Somatic mutation – mutations in the organism’s body Affect the organism, but not passed on to offspring Ex. Skin cancer, leukemia, any cancer

10 What causes mutations? Mutagens – agent that causes mutations to occur within a cell. Ex. Ionizing radiation, Base analogs, Intercalating agents, and Bromine

11 Types of mutations Chromosome mutations – changes in the structure of a chromosome or loss of an entire chromosome. Deletion – loss of piece of DNA due to chromosomal breakage Duplication – Chromosomes steal part of homologs and have both alleles for each gene involved Inversion – piece of DNA breaks off and reattaches itself in opposite direction Translocation – chromosome breaks off and reattaches to a non-homologous chromosome Nondisjunction – chromosome does not properly separate from its homolog during meiosis

12 Chromosome Mutations

13 Nondisjunction Results in gametes receiving to many or too few chromosomes Ex. Down Syndrome = trisomy of chromosome 21

14 What kind of chromosomal mutation is this?
Original chromosome Duplication Translocation Inversion Deletion

15 What kind of chromosomal mutation is this?
Original chromosome Duplication Translocation Inversion D. Deletion

16 Gene Mutations May involve a large section of DNA or a single nucleotide within a codon Point mutation – the substitution or change of a single nucleotide Insertion or Deletion – one nucleotide is removed from or added to a sequence Frame shift mutation – occurs when codons are incorrectly grouped

17 Point Mutation Can result in
No effect - the protein structure is not changed Missense – one amino acid is replaced by another Nonsense – prematurely stop codon in amino acid sequence

18 Point mutation Ex. Sickle cell anemia –mutation in a single nucleotide that causes the malformation of the hemoglobin molecule which carries oxygen to our cells

19 Insertion and Deletion
The removal or addition of a nucleotide base to a sequence usually results in a frameshift mutation.

20 Using the genetic code provided, which chain of amino acids corresponds to this mRNA sequence?
UCAAUGGUCUGA Glu, Tyr, Met, Arg Ser, Val, Arg, Stop Ser, Met, Val, Stop Val, Iso, Asp, Stop

21 What if the first G was changed to a C, what would the new amino acid chain be?
UCAAUGGUCUGA Glu, Tyr, Met, Arg Ser, Leu, Arg, Stop Val, Ile, Ser, Stop Ser, Iso, Val, Stop

22 What affect does this mutation have on the function of the protein?
Proteins are folded in a specific fashion according to the amino acid sequence it contains. This would cause the function of the protein to be severely reduced or not functional at all.

23 Mutations lead to Evolution
Mutations are not always bad, they often provide variations on proteins and sometimes these are advantageous to us. Survival of the fittest and Natural selection.

24 How can one tell the history of hereditary traits in his or her family?
Pedigree – diagram of genetic history of an individual showing how traits are inherited over several generations

25 Pedigrees Dominant disorders Recessive disorders
Genetic disorders – diseases or debilitating conditions that have a genetic basis Carriers – individuals with one copy of a recessive autosomal allele; do not usually express the disorder but can pass on to offspring

26 Polydactyly Dominant trait that results in offspring with extra fingers or toes.

27 Hemophilia A sex-linked, recessive genetic disorder that affects the individuals ability to clot blood.

Download ppt "Cancer & Mutations Powerpoint"

Similar presentations

Ads by Google