Exam 4 Flashcards
Describe the characteristics of cancer cells that distinguish them from normal cells. (7)
- Are not differentiated; don’t contribute to bodily functions.
- Have abnormal nuclei and cell shape.
- Unlimited replication.
- lack contact inhibition and divide even when crowded
- disregard regulation by growth factors
- cause blood vessels to grow/make new ones for nutrients
- may metastasize.
Distinguish between a proto-oncogene and a tumor suppressor gene with regard to their effects on the cell cycle
proto-oncogene: cause cancer when mutated. They promote cell cycle and prevent apoptosis.
Tumor suppressor: inhibit cell cycle and promote apoptosis. Cannot do this when mutated.
identify the common types of cancers and the body system with which each is associated
Carcinoma: epithelial tissues. Inner/outer coverings of organs.
Sarcoma: muscles and connective tissue, and bone
Leukemias: blood
Lymphomas: lymphoid tissue
Blastoma: composed of immature cells.
Explain how heredity, the environment, certain viruses, and diet contribute to cancer.
Heredity: traits can increase the chances of cancer
Environment: mutagens (causes mutations), carcinogens (chemical that causes cancer), radiation , UV light, nonionizing radiation, organic chemicals, pollutants
Viruses: Hepatitus B and C cause liver cancer. HPV causes cervical and penile cancer. AIDS causes kaposi sarcoma.
Diet: high fat diet and obese can cause breast and prostate. Low fiber causes colon. Processed meats increase stomach cancer. High alcohol causes liver.
list the seven warning signs of cancer
- Chang in bower/bladder habits
- sore throat that does not heal
- unusual bleeding or discharge.
- thickening in breast of else wear
- indigestion or difficulty swallowing
- Obvious change in wart or mole
- nagging cough
Describe the tests that may be used to diagnose cancer (11)
Self exam: ABCDE (asymmetry, border is irregular, color, larger than 6mm, elevated)
Digital Rectal Exam: finger in but
Colon cancer: camera in butt or fecal blood test
Blood test
Urinalysis
Mammography: Xray
MRI
Ultrasound
Biopsies: remove cells for examination
Tumor marker test: tests for antibodies from tumors.
Genetic test: test for mutations in proto-oncogenes
describe how surgery, radiation therapy, chemotherapy, and newer methods are used to treat cancer.
Surgery: removing tumor
Radiation: ionizing radiation cause chromosomal breakage and cell cycle disruption
Chemo: treats entire body. Hopes to kill cancer cells that escape
tumor. Kill cells by damaging their DNA and interfere with DNA synthesis.
Newer Methods:
-Immunotherapy (vaccines against cancer antigens, engineered immune cells, designed antibodies.)
-p53 gene therapy (causes cancer cells to produce p53 causes apoptosis)
-Antiangiogenetic drugs (decrease tumor blood supply causes them to shrink)
summarize how polygenic inheritance, pleiotropy, codominance, and incomplete dominance differ from simple one-trait crosses.
Polygenic - several alleles, the effects of the each dominant allele are additive.
Pleiotropy - single mutant gene affects two or more unrelated traits.
Codominance - alleles are equally expressed.
Incomplete dominance - phenotype is an intermediate.
explain why x-linked disorders are more common in males than females.
X linked disorders are more common in males because they only need one recessive allele to be effected by the disorder.
Compare and contrast the structure and function of DNA and RNA
DNA: Double helix structure, nucleotides made of phosphate and sugar (backbone), and nitrogen base (ACGT)
Replicates, stores information in genetic code, undergoes mutation to provide variability.
RNA: AUCG nucleotides, single stranded
Explain why DNA replication is semiconservative
Each new strand has an old and new strand. The new strand is copied from the old strand.
Summarize the major steps in DNA replication (3)
- DNA helicase unzips and unwinds, breaking bonds
- DNA polymerase adds new DNA nucleotides
- DNA synthesis occurs in opposite directions. One strand goes beginning to end, the other makes copies in segments.
Explain the role of mRNA, tRNA, and rRNA in a cell
mRNA: messenger. Temporary copy of a gene carried from DNA to ribosomes where protein is made.
rRNA: helps with reading RNA to make protein
tRNA: carries amino acid to ribosome.
Understand the structure and function of genetic code
genetic code is the sequence of bases in DNA and mRNA that code for amino acids. Its a three base sequence in mRNA (codon)
Describe the process of gene expression via transcription and translation
Transcription: DNA is template for the RNA molecule. RNA polymerase makes RNA.
-DNA unzips and new strand is made based on each strand. Introns must be removed and exons are brought together.
Translation: copy is used as instructions to make protein in ribosome.
Explain how gene expression may be regulated by a cell
Pretranscription control: prevents DNA from being transcribed by keeping them tightly coiled.
Transcriptional control: Transcription factors must be turned on in order to transcribe their gene
Posttranscriptional control: DNA can still be altered, splicing
Translational control: translation is prevented or inhibited
Posttranslational control: Includes protein being folded correctly and taken to correct destination.
recognize the importance of DNA sequencing to the study of biology
DNA sequencing is determining the order of nucleotides in DNA.
We can identify alleles, identify suspects through DNA, understand evolution, and make copies of DNA segments using polymerase chain reaction.
state the purpose of the polymerase chain reaction and DNA cloning
Make millions of copies of a specific segment of a certain gene.
Can be used for fingerprinting, test for viral infections, compare bodily substances, and identify bodies for forensics.
Cloning makes an identical copy of DNA, cells, or organism. DNA cloning produces many copies of a gene.
Understand the goals of genome editing.
To cure diseases by replacing the mutated gene.