Term
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Definition
| Deleting part of the chromosone |
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Term
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Definition
| Moving chromosone parts around. Can be unidirectional or reciprocal. |
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Term
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Definition
| Literally flipping part of the chromosone |
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Term
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Definition
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Term
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Definition
| Gaps or breaks in chromosomes. More than 100 found in human genome. |
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Term
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Definition
| Chemical substances that cause chromosomal breaks. |
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Term
| Defect and phenotype of Cri-du-chat syndrome |
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Definition
Phenotype:
Low birth weight and slow growth.
Mental retardation.
Cat-like cry.
Craniofacial abnormalities.
Defect: 5p deletion |
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Term
| Defect and phenotype of Prader-Will Syndrome |
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Definition
Phenotype:
Reduced growth rate.
Obesity; excessive appetite.
Craniofacial abnormalities.
Strabismus.
Mental retardation varies from mild to severe.
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Defect:
PWS linked to chromosome 15.
Metaphase banding pattern is normal.
Prophase banding pattern showed a deletion at 15q11.13 |
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Term
| Defect and phenotype of Martin Belle (Fragile X) syndrome |
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Definition
X-linked dominant.
Phenotype:
Mental retardation; may vary from mild to profound.
Physical features may vary.
Variable expression.
Defect:
Xq28 fragile site.
FMR1 gene (abnormal CGG repeats). |
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Term
| Paracentric inversion vs. Pericentric inversion |
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Definition
Para - does not involve the cenrromere
Pari - Involves the centromere |
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Term
| Describe the nature of unidirectional translocation |
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Definition
| When part of one chromosone sticks to another without the exchange of another piece. Only one gives. |
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Term
| Describe the nature of a Robertsonian transaction |
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Definition
| The short arm of two chromosones break off and the long parts fuse into a single chromosone. |
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Term
| Describe the nature of a reciprocal translocation event |
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Definition
| Exchange between to homologs without any loss |
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Term
| Compare a terminal deletion to an interstitial deletion. |
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Definition
Terminal = end
Interstitial = middle |
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Term
| Describe the formation of isochromosones and ring chromosones |
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Definition
Isochromosome - Metacentric chromosomes produced during MEIOSIS or MITOSIS when the CENTROMERE splits transversely instead of longitudinally. The chromosomes produced by this abnormal division are one chromosome having the two long arms of the original chromosome, but no short arms, and the other chromosome consisting of the two short arms and no long arms. Each of these isochromosomes constitutes a simultaneous duplication and deletion.
Ring - Ends break off and the remaining ends stick to each other. |
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Term
| Define the following; mutation, point mutation, substitution mutation, missense mutation, nonsense mutation, intercalation, frame shift mutation, amplification mutation, alkalation agent, thymine dymer, UV light, and base analogs |
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Definition
Mutation: Any change in the sequence of nucleotides in the DNA molecule.
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Point mutation: single base pair change.
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Substitution mutation-one base substituted for another, i.e. A for G.
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Misssense mutation-change in codon leads to change in amino acid, i.e. GAA to GUA (glu to val).
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Nonsense mutation-change in codon to a stop codon.
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Thymine dimers cannot be replicated. Gaps are left in the DNA.
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Term
| Explain how mutation rates can be calculated |
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Definition
| Look at frequencies of dominant alleles and measure the frequency of one vs. the other. |
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Term
| Explain how a base analog can cause a substitution mutation |
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Definition
| By substituting itself into the DNA in the place of something else.. Affects are during replication. THIS IS A SUBSTITUTION, not AN INSERTION. |
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Term
| Explain how alkalating agents damage DNA. |
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Definition
| Affect resting DNA. Chemical modification of bases. Base the mis-pairs. This is a substitution process vs. an insertion process. |
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Term
| Explain how UV Light damages DNA |
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Definition
| The energy in UV light is absorbed directly by DNA and results in mutations |
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Term
| Explain how frame-shift mutations arise. |
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Definition
| INTERCCALATING AGENTS can insert themselves into DNA, distorting the double helix. When this region is replicated a frame-shift mutation can arise. |
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Term
| Describe two cellular mechanisms for repairing DNA. |
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Definition
Photoreactivation - Specific for thymine dimers. An enzyme, photolyase, cuts thymine dimers in half, and regenerates the original thymines.
Excision repair - Can recognize and repair a wide variety of DNA damage. Involves a large collection of proteins and enzymes |
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Term
Briefly discuss the DNA repair defects found in the following disorders:
Xeroderma pigmentosum
Cockayne syndrome
Ataxia telangiectasia |
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Definition
Xeroderma pigmentosum:Autosomal recessive.
Genetically heterogeneous.
Phenotype:
Defect in excision repair. Results in numerous skin cancers if individuals are exposed to sun light.
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Cockayne syndrome:
Early aging; growth deficiency; neurological effects.
Defect in repair of transcriptionally active DNA.
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Ataxia telangiectasia:
Poor balance and coordination; red marks on face. Increased sensitivity to radiation.
Increased cancer risk.
Defect in detecting DNA damage during cell cycle. |
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Term
| Compare normal cells to cancer cells |
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Definition
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Term
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Definition
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Term
| Describe the Ames test for mutagenic activity |
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Definition
| Cells are placed on media without HIS. HIS- -> HIS+ means growth. |
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Term
| Explain the relationship between mutanagenic and carcinogenic activity |
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Definition
Mutagens = 90% of Carcinogens
Mutations lead to carcinogens. |
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Term
| Explain how rats are used to test chemicals for carcinogenic activity. |
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Definition
| Repeated application of the carcinogen. |
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Term
| Explan the relationship between somking and lung cancer. |
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Definition
| More than 4000 known compounds are generated from a lighted cigarette. |
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Term
| Define metastasis, sarcoma, carcinoma, and blastoms |
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Definition
Sarcoma connective tissue
Carcinoma epithelial tissue
Blastoma embryonic tissue
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Metastasis:
1. Invasion of surrounding tissue.
2. Penetration of vascular system.
3. Transport to new site.
4. Colonization of new site.
5. Proliferation at new site |
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Term
| Explain the relationship between chromosone changes and cancer |
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Definition
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Term
| Describe the Philadelphiaq (ph) chromosone and its role in chronic myelogenous leukemia |
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Definition
c-abl at breakpoint of Ch. 9.
bcr at breakpoint of Ch. 22.
Hybrid bcr-abl gene is produced (Ch.22).
Abnormal bcr-abl fusion protein switches on cell division in lymphoid cells resulting in CML. |
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Term
| Define oncogene and anti-oncogene |
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Definition
oncogene - cancer producing gene
anti-oncogene - prevents cancer |
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Term
| Discuss the viral origin of certain types of cancer |
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Definition
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Term
| Compare a non-tumor producing retrovirus to a tumor producing retrovirus. |
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Definition
| Non-tumor missing oncogene |
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Term
| Define alpha particles, beta particles, gamma rays, x-rays, neutrons, and ionizing radiation. |
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Definition
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Term
| Describe the effect of ionizing radiation on cellular water and on DNA. |
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Definition
| As radiation strikes the molecules in cells, electrons are removed, creating ions and charged atoms. Such ionized molecules are highly reactive and can cause mutations in DNA. Example - water molecule ionized, these ions might react with DNA to produce mutation. |
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Term
| Describe the effect of ionizing radiation on chromosone structure and behavior. |
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Definition
| As radiation strikes the molecules in cells, electrons are removed, creating ions and charged atoms. Such ionized molecules are highly reactive and can cause mutations in DNA. Example - water molecule ionized, these ions might react with DNA to produce mutation. |
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Term
| Explain the breakage-fusion-bridge cycle of cell death |
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Definition
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Term
| Describe the effects of large doses of ionizing radiation on rapidly dividing cell populations such as bone marrow and epiuthelial cells. |
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Definition
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Term
| Describe the effects of the atom bomb on the populations of Hiroshima and Nagasaki |
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Definition
Among survivors cancer rates have increased, especially leukemias and lung cancer.
No increase in birth defects.
No increase in cancer in offspring of survivors. |
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Term
| List the maximum dose of ionizing radiation permitted for the general population |
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Definition
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Term
| Compare the short and long term effects of 3 Mi Isle and Chernobyl |
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Definition
Chernobyl: 31 people died instantly.
Several hundred people died in the following weeks.
32,000 people have died in the last 10 years.
Thyroid cancer among children living in Belarus has risen 10 fold.
Increase in human mutation rate. |
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Term
| Describe the effects of large doses of radiation on cells, tissue, and the whole person. |
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Definition
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Term
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Definition
| Any agent that increases the frequency of birth defects. |
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Term
| Describe the effects of the following agents on human development: |
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Definition
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Term
| Define anitgen, antibody, and lymphocyte |
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Definition
An antigen is any substance that causes your immune system to produce antibodies against it. The antigen may be a foreign substance from the environment (such as chemicals, bacteria, viruses, or pollen) or formed within the body (such as bacterial toxins or tissue cells).
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An antibody is a protein used by the immune system to identify and neutralize foreign objects like bacteria and viruses. Each antibody recognizes a specific antigen unique to its target.
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A lymphocyte is a type of white blood cell involved in the human body's immune system. There are two broad categories of lymphocytes, namely T cells and B cells. Lymphocytes play an important and integral part of the body's defenses. |
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Term
| Describe the nature of the ABO locus and alleles. |
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Definition
1 gene, 3 alleles
A - Codes for A
B - Codes for B
O - Codes for nothing |
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Term
| List the ABO blood types and the antibodies each can produce |
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Definition
A - Anti B
B - Anti A
O - Anti A and B
AB - Anti for none |
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Term
| Describe briefly how antibodies are produced |
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Definition
| .Produced by B-Lymphocytes |
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Term
| Describe the nature of the Rh blood group system. |
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Definition
Genotype ----- Phenotype
RR or Rr ------type Rh+
rr------------- type Rh- |
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Term
| Describe the cause and treatment of Rh incompatibility |
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Definition
Mating between Rh- women and Rh+ men.
Mother is rr and has Rr baby. Baby's blood gets into mothers system and she developes antibodies for Rh+. No affect on first baby, but now mother's system is primed to attack second baby with Rh+ blood type. The treatment is to kill the first baby's blood in the mother's system to keep her from developing antibodies. |
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Term
| Explain the role of T and B lymphocytes in the immune system |
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Definition
The T-lymphocyte or T-cell plays a role in destruction of foreign cells and tissues.
It is the major reason for transplant tissue rejection. |
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Term
| Describe the nature of the HLA locus and the role of hiscompatibility antigens in organ transplants |
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Definition
| HLA Alleles are inherited as a haplotype, meaning you get one exact copy from both parents. |
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Term
| Describe the use of cyclosprin in organ transplants |
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Definition
1. Steroids - suppresses B-cells and T-cells.
2. Cyclosporin - suppresses T-cells only. |
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Term
| Explain the relationship between HLA alleles and disease. |
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Definition
Disease-----------------------HLA Allele
Ankylosing spondylitis B27
Rheumatoid arthritis C3, D4
Hodgkin disease (cancer) A1, B5, B8, B18
Myasthenia gravis A8 |
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Term
| Describe the nature and causes of severe combined immune defeciency syndrome |
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Definition
Due to a defect in the adenosine deaminase (ADA) gene.
ADA activity is necessary for the growth and development of B and T lymphocytes.
Bubble Boy.
Current Therapy:
Gene Engineered Lymphocytes |
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Term
| Describe the causes and symbtoms of AIDS. |
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Definition
CD4 (helper/inducer) T lymphocytes.
Macrophages
CD4 (helper/inducer) T lymphocytes: up-regulate the system.
CD8 (suppressor/cytotoxic) T lymphocytes: down-regulate the system.
Immunodeficiency.
Opportunistic diseases.
Kaposi’s sarcoma. |
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Term
| Explain how the AIDS virus affects the immune system. |
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Definition
Normal: CD4/CD8 = 2/1
AIDS: CD4/CD8 = 1/2 |
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Term
| Describe how AIDS can be treated and prevented now and in the future. |
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Definition
Nucleotide inhibitors: Inhibit replication.
Protease inhibitors: Inhibit replication.
Vaccine: Prevent HIV infections. |
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