click below
click below
Normal Size Small Size show me how
morerbwrksheets
more radiobio worksheets from casey
| Question | Answer |
|---|---|
| This can be seen in karyotyping | Main chain |
| Crosslinking | Sticky spurs |
| Point lesions | Messes with chemical bonds of DNA not visible in karyotyping |
| Dicentric | 2 centromeres |
| Accentric | No centromeres |
| If two acentric fragments do not find anywhere to go and come together what happens | There is a loss of genetic information(this is the most common occurance) |
| Ring chromosome | Don’t have ends so attaches to itself this causes death of the chromosome and the more you have the higher the chance of cell death |
| Radiation effects are | Non-specific |
| Direct hit | High LET radiations |
| X ray damage is caused by __________ness | Randomness it does not go after a particular area of cell |
| Radiolysis | The interaction of water with radiation |
| 90 to 95 percent of human interaction is with | water, indirect |
| Multi target multi hit | apply to human cells, more than one target |
| Single target single hit | Applies to enzymes, viruses, and simple cells such as bacteria |
| D37 mean | The measure of the radiosensitivity of biologic tissue |
| Low D37= | High sensitivity (radiosenstive) |
| High D37= | Low sensitivity (radioresistant) |
| Do means | Lethal dose |
| Large Do = | Radioresistant cells takes a high dose to kill |
| Small Do= | Radiosensitive cells |
| DQ | Threshold dose |
| The wider the shoulder the | more recoverability |
| The smaller the shoulder the | Less chance of recovery |
| Cell cycle time takes | 24 hours |
| How long it takes is determined by | G1 phase |
| High LET is more damaging than | low LET |
| Different types of ionizing radiation have different | LET |
| The efficiency for producing a given response is related to | Linear Energy transfer |
| Part of the law of b and t | stem cells are radiosensitive |
| The law of b and t states that | Radiosensitivity increases with proliferation rate |
| The response of tissue to radiation is principally a function of | dose |
| The RBE | Is a descriptor of the type of radiation |
| The law of b and t relates to | radiosensitivity and cellular differentiation |
| This is higher for high LET radiation than for low LET radiation | RBE |
| How is LET measured | KeV/Um |
| This has a high LET | Alpha particles |
| The maximum value of RBE is | 3 |
| Dose fractionation is less effective than a single dose because | Recovery, occurs between doses |
| The OER | Is highest for low LET radiation |
| LET is useful for expressing radiation | Quality |
| What is related to radiation protection as LET is related to radiobiology | Radiation weighting factor (WR) quality factor |
| This has low LET | Cobalt 60 gamma rays |
| Dose protraction relates principally to | Dose rate |
| Considered a physical dose-modifying factor | Dose protraction |
| Considered a biological dose modifying factor | The oxygen effect |
| Dose fractionation is less effective than an equal single dose because of | Cellular recovery |
| Why do we develop radiation dose-response relationships | To predict the harmful effects of radiation after an accident |
| Radiation induced damage in tissue | Is greater in the presence of oxygen |
| When one considers the biologic modifying factors to a radiation response | Age is a factor and sex is a factor |
| Why is a linear,nonthreshold dose response relationship used as a model for radiation protection guides | Because in a nonthreshold dose relationship, any dose is expected to produce a response |
| The least sensitive time in life to radiation exposure is | There is no least sensitive time |
| Exhibits a threshold type of radiation dose-response relationship | Cataracts |
| When a radiation dose-response relationship intercepts the response axis at a positive value | That response is not related to radiation |
| follows a nonlinear, threshold type of dose-response relationship | Death |
| dose limits (DLs) are based on this type of radiation dose-response relationship | Linear, nonthreshold |
| the late effects of diagnostic x rays probably follow which type of radiation dose-response relationship | Linear, nonthreshold |
| a wide error bar on a graphic data point indicates what | Little confidence |
| this factor has no influence on response to radiation exposure | Occupation |
| these do have an influence on the response to radiation exposure | Age, dose protraction, oxygen tension, and sex |
| humans are most sensitive to radiation | In utero |
| when an irradiated cell dies before the next mitosis, this is called | Interphase death |
| a linear, nonthreshold dose response relationship | Suggest that even the smallest dose may be risky |
| when a linear, nonthreshold dose response relationship intersects the response axis at zero dose, this means that | There is a natural incidence of the response |
| the genetically significant dose (GSD) | Depends on the average gonadal dose for various procedures |
| RBE | 1 and max is 3 |
| LET of diag x ray is | 3 kev/m |
| Radiation effects at the total body occur because of | radiation damage to cells |
| Cellular damage occurs because of | molecular responses to radiation |
| DQ is the | Threshold dose or shoulder dose |
| If undifferentiated cells are irradiated in vivo | Such cells are sensitive to radiation |
| Phase of the cell cycle that is considered most resistant | Late S phase |
| When cell survival curves are used, the measure of cell radiosensitivity is | DO |
| When irradiated with high LET radiation, human cells follow which of the following models | The multitarget, single hit model |
| The probability of human cell death can be computed | Using the poisson distribution |
| If a dose equal to D37 were uniformly distributed, what percentage of cells would survive | 0% |
| Means mean lethal dose | DO |
| The multitarget, single hit model | Presumes a threshold |
| The difference in generation time among different types of cells is due mainly to the length of | the G1 phase |
| Does not affect the radiation response of mammalian cells | Sex of cell |
| Does affect the radiation response of mammalian cells | Dose rate, LET, presence of oxygen, stage of the cell in its cycle |
| In a cellular radiobiology | Single cells are allowed to grow into colonies |
| According to the multitarget model of cell lethality | Cells have more than one critical target, each of which has to be inactivated for cell death |
| According to target theory | Radiation interacts randomly |
| When irradiated with x-rays, human cells follow | the multitarget, single hit model |
| To explain radiation effects on living cells, target theory states that | A target can receive a hit by direct or indirect effect |
| If a dose equal to D37 were randomly distributed what percentage of cells would die | 63% |
| Of the various macromolecules that are sensitive to radiation, the most sensitive is | DNA |
| Usually, radiation interacts with DNA | Indirectly |
| Free radical ions are associated with biologic injury induced by what type of radiation | Diagnostic s rays |
| A reactive atom or molecule that has an unpaired electron in its outer shell is called | Free radical |
| The genetic code of DNA | Is transcribed by mRNA |
| If an affect of radiation on molecular DNA | Cross-linking |
| After a low radiation dose, most cellular radiation damage that results in a late total body effect occurs because of | Point lesions |
| The biologically reactive molecular byproducts formed during radiolysis of water are thought to be | H* and OH* |
| Radiation may interfere with DNA synthesis by | The G1 effect, which is the failure to commence DNA synthesis because of damage that occurs during the G1 period |
| May occur in DNA molecules as a result of irradiation | A double strand break |
| When water is irradiated products of the initial interaction are | OHO+ and e- |
| Example of anabolism | Protein synthesis |
| Radiation induced changes in DNA that result in genetic damage follow which type of dose response relationship | Linear non threshold |
| This is a free radical | HO2 |
| When molecules are irradiated | In suspension, they are irradiated in solution |
| Radiation effects at the total body level occur mainly because of | Indirect effect |
| Hydrogen ion | H+ |
| Hydroxyl free radical | OH* |
| Positively charged water | H2O+ |
| Hydroxyl ion | OH- |
| Hydrogen free radical | H* |