In human beings, how many genes are contained in all 46 chromosomes?

A. approximately 300

B. approximately 3000

C. Approximately 30,000

D. Approximately 300,000

The nucleolus contains which of the following?

A. Centrosomes

B. Ribonucleic acid

C. Ribosomes

D. Lysosomes

B. ribonucleic acid

In the human cell, protein synthesis occurs in which of the following location?

A. Nucleus

B. Mitochondria

C. Ribosomes

D. Endoplasmic reticulum

C. Ribosomes

Interphase consists of which of the following phases?

A. M, G1 and S

B. G1, S, and G2

C. S, G2, nd M

D. G2, M, and G1

B.  G1, S, and G2

Carbohydrates also may be referred to as

a. Lipids

b. Nucleic acids

c. Hormones

d. Saccharides

d. Saccharides

DNA regulates cellular activity indirectly by reproducing itself in the form of ______ to carry genetic information from the cell nucleus to ribosomes located in the cytoplasm.

A. Messenger DNA

B. Messenger RNA

C. Messenger REM

D. Transfer RNA

B. Messenger RNA

Human cells contain which four major organic compounds?

A. Nucleic acids, water, protein, and mineral salts

B. Mineral salts, carbohydrates, lipids, and proteins

C. Carbohydrates, lipids, nucleic acids, and water

D. Proteins, carbohydrates, lipids, and nucleic acids

D. Proteins, carbohydrates, lipids, and nucleic acids

Which of the following is a process of reduction cell division?

A.  Mitosis

B. Meiosis

C. Molecular synthesis

D. Amniocentesis

B. Meiosis

Which of the following cellular organelles function as cellulr garbage disposals?

A.  Endoplasmic reticulum

B.  Mitochondria

C.  Lysosomes

D.  Ribosomes

C. Lysosomes

Which of the following describes the nuclear envelope that separates the nucleus from other parts of the cell?

A. Single membrane

B. Double-walled membrane

C. Triple-walled membrane

D. Quadruple-walled membrane

B. Double-walled membrane

Which of the following are functions of the cell membrane?

 1. Protecting the contents of the cell from its environment.

 2. Controlling the pssage of water and other materials into and out of the cell.

 3. Allowing all substances to pass

A. 1 and 2 only

B. 1 and 3 only

C. 2 and 3 only

D. 1, 2, and 3

A. 1 and 2 only

Lipids are also referred to as

A. Amino acids

B. Carbohydrates

C. Fats

D. Sugars

C. Fats

The primary energy source for the cell is

A.  Amino acids

B.  Glucose

C.  Protein

D.  Phosphate

B. Glucose

Cytosine bonds only with wich of the following nitrogenous organic bases?

A.  Adenine

B. Guanine

C. Thymine

D.  Uracil

C. thymine

Which of the following statements is NOT true?

A.  Lysosomes are sometimes referred to as "suicide bags."

B.  Adenosine triphosphate (ATP) is essential for sustaining life.

C.  the Golgi apparatus or complex, is the powerhouse of the cell.

D.  the nucleus is the "hart" of the cell.

When ionizing radiation is used to destroy malignant cells, an attempt is also made to spare healthy surrounding tissue.  In radiation therapy this concept is referred to as a(an)

A.  Enzyme repair effect

B.  therapeutic ratio

C.  Tissue tolerance effect

D.  Malignanct cell annihilation effect

Twenty-two different ______ are involved in protein synthesis.

A.  Amino acids

B.  Antibodies

C.  Enzymes

D.  Hormone

The process of locating and identifying the genes in the human genome is called

A.  Gene detecting

B.  Gene extrapolation

C.  Gen tracking

D.  Mapping

D.  Mapping

Approximately 80% to 85% of the weight of the human body is

A.  Bone

B.  Fat-like substances

C.  Mineral salts

D.  Water

D.  Water

Meiosis is the process of

A. Converting inorganic substances into organic substances

B.  Identifying genes in the human genome

C.  Reduction cell division

D.  Repairing breaks in DNA

C.  Reduction cell division

Water perfoms which of the following function int he human body?

1.  Maintains a constant core temperature of 37 degrees celcecus.

2.  Regulates the concentration of dissolved substances.

3.  Lubricates skelatal articulations (joints)

A.  1 and 2 only

B.  1 and 3 only

C.  2 and 3 only

D.  1, 2, and 3

D.  1, 2 and 3

Which of the following is of primary importance in maintaining adequate amounts of intracellular fluid?

A.  Deoxyribose

B.  Glucose

C.  Potassium

D.  Ribose

C.  Potassium

The S phase of mitosis is the

A.  Pre-DNA synthesis phase

B.  Actual DNA synthesis periord

C.  Port-DNA synthesis phase

D.  Phase when DNA synthesis multiplies by a factor of 4.

B.  Actual DNA synthesis period.

When a cell divides, the genetic-containing material contracts into tiny rod-shaped bodies called

A.  Golgi apparatus

B.  Chromosomes

C.  Mitochondria

D.  Nucleotides

B.  Chromosomes

Nitrogenous base pairs form the

A.  Hormones needed by various endocrine glands inthe body.

B.  Mitotic spindle

C.  Steps, or rungs, of the DNA ladderlike structure

D.  Sugars the body needs for energy.

The large, double-membrane, oval, or bean-shaped, structures that function as the powerhouses of the cell are called

A.  Endoplasmic reticulum

B.  Golgi apparatus

C.  Mitochondria

D.  Ribosomes

C.  Mitochondria

When somatic cells divide, they undergo

A.  Centrosome removal

B.  Meiosis

C.  Mitosis

D.  Nuclear collapse

C.  Mitosis

Radiation damage is observed on which of the following three levels?

A.  Molecular, cellular, and inorganic

B.  Molecular, cellular, and organic

C.  Microscopic, molecular, and organic

D.  Organic, Inorganic, and cellular

B.  Molecular, cellular, and organic

Molecular damage results in the formation of structurally

A.  Changed molecules that permit cells to continue completing normal function

B.  Changed molecules that may impair cellular function

C.  Unchanged molecules that permit cells to continue functioning normally

D.  Unchanged molecules that may impar cellular function.

B.  Changed molecules that may impair cellular function.

According to the target theory, if only a few non-DNA cell molecules are destroyed by radiation exposure, the cell probably will

A.  not show any evidence of injury after irradiation

B.  Show evidence of injury after irradiation

C.  Show evidence of severe impairment after irradiation

D.  Die

A.  no show any evidence of injury after irradiation

Each cell's function is determined and defined by the structures of its constituent molecules.  If these structurs are altered by radiation exposure, the following may result:

1.  Disturbance of the cell's chemical balance

2.  Disturbance of cell operation

3.  Failure of the cell to perform normal tasks

A.  1

B.  1 and 2 only

C.  1 and 3 only

D.  1, 2, and 3

D.  1, 2, and 3

Chromosome aberrations happen when irradiation occurs

A.  Early in interphase

B.  late in prophase

C.  At the start of metaphase

D.  At the end of telophase

A.  Early in interphase

Which of the following are examples of distorted chromosomes?

1.  Anaphase bridges

2.  Dicentric chromosomes

3.  Ring chromosomes

A.  1 and 2 only

B.  1 and 3 only

C.  2 and 3 only

D.  1, 2, and 3

D.  1, 2, and 3

Which of the following may be used to explain cell death and nonfatal cell abnormalities caused by exposure to radiation?

A.  Covalent cross-lining

B.  Bergonie-Tribondeau Law

C.  Programmed cell death

D.  Target theory

D.  Target theory

X-rays and gamma rays can be referred to as streams of particles because of a property known as

A.  LET

B.  RBE

C.  Wave-particle duality

D.  Wave-particle fragmentation

C.  Wave-particle duality

The random interacton of x-rays with matter produces a variety of structural chnges in biologic tissure, including

1.  A single-strand break in one chromosome

2.  More than one break in the same chromosome

3.  Stickiness, or clumping together, of chromosomes

A.  1 and 2 only

B.  1 and 3 only

C.  2 and 3 only

D.  1, 2, and 3

D.  1, 2, and 3

Why are repair enzymes usually able to reverse the cellular damage generally caused by low-level ionizing radiation?

A.  Damage to DNA is sublethal.

B.  Irradiated cells are hypoxic.

C.  Only organic molecules are damaged.

D.  LET failed to occur.

A.  Damage to DNA is sublethal

What governs the radiation dose required to cause apoptosis?

A. Changes in the cell protein content

B.  The phase of the cell cycle in the individual cell is undergoing.

C.  The radiosensitivity of the individual cell

D.  The number of cells irradiated.

C.  The radiosensitivity of the individual cell

Which of the following describes the ratio of the radiation dose required to cause a particular biologic response of cells or organisms in an oxygen-deprived environment to the radiation dose required to cause an identical response under normal oxygenated conditions?

A.  OER

B.  Oxygen biologic effectiveness ratio

C.  Oxygen dose-response relationship

D.  Oxygen threshold ratio

A.  OER

Which of the following is a method of displaying the sensitivity of a particular type of cell to radiation?

A.  Cell survival curve

B.  Hypoxic cell measurement curve

C.  Radiolysis of water

D.  Radiation dose-response curve

A.  Cell survival curve

Where in the human body are lymphocytes manufactured?

A.  Bone marrow

B.  Epithelial tissue

C.  Liver

D.  Pancreas

A.  Bone marrow

Which of the following defines the ratio of the dose of a reference radiation (conventioally 250kVp x-rays) to the dose neede to produce the same biologic reaction in a given experiment?

A.  LET

B.  RBE

C. Wr

D.  Low-level radiation effectiveness

B.  RBE

A biologic reaction is produced by 6 Gy (600 rads) of a test radiation.  It takes 36Gy (3600 rads) of 250 kVp x-ray to produce the same biologic reaction.  What is the RBE of the test radiation?

A.  3

B.  6

C.  9

D.  12

B.  6

A hydroperoxyl radical (HO-2) is formed when a hydrogen free radical (H-) combines with

A.  A hydrogen ion (H+)

B.  A hydroxyl ion (OH-)

C.  Molecular oxygen (O2)

D.  Another hydrogen free radical (H-)

C.  Molecular oxygen (O2)

LET is an important factor for

A.  Assessing potential tissue and organ damage from exposure to ionizing radiation

B.  Assessing the characteristics of ionizing radiation (e.g. charge, mass, and energy)

C.  Determining the OER

D.  Removing electrons from tissue exposed to ionizing radiation.

A.  Assessing potential tissue and organ damage from exposure to ionizing radiation

Because high-LET radiations deposit more energy per unit length of biologic tissue traversed, they are

A.  More destructive to biologic matter than low-LET radiations

B.  Significantly less destructive to biologic matter than low-LET radiations

C.  Slightly less destructive to biologic matter than low-LET radiations.

D.  Not comparable to low-LET radiations because they do not deposit any energy per unit length of biologic tissue traversed.

A.  More destructive to biologic matter than low-LET radiations.

Ring chromosomes, dicentric chromosomes, and anaphase bridges are examples of

A.  Normal chromosomes

B.  Chromosomes about to divide

C.  Distorted chromosomes

D.  Chromosomes that carry appropriate genetic information

C.  Distorted chromosomes

Because even low doses of ionizing radiation from diagnostic imaging procedures can cause chromosomal damage, which of the following should be done whenever pssible?

A.  Avoid all x-ray procedures until age 60

B.  Use a low kVp and high mAs technique

C.  Shield the reproductive organs

D.  Limit all radiographic procedures to just one projection per patient.

C.  Shield the reproductive organs

Immature ova are

A.  Somewhat radioinsensitive

B.  Significantly radioinsensitive

C.  Slightly radiosensitive

D.  Very radiosensitive

D.  Very radiosensitive

When biologic effects from ionizing radiation demonstrate the existence of a threshold and the severity of that damage increases as a consequence of increased absorbed dose, the events are considered

A.  Deterministic

B.  Probabilistic

C.  Stochastic

D.  Unimportant

A.  Deterministic

Which of the following measures the effectiveness of ionizing radiation in causing mutations?

A.  LD 50/30

B.  Doubling dose

C.  Relative biologic effectiveness (RBE)

D.  Dose-response curve

B.  Doubling dose

Recent studies of atomic bomb survivors tend to support the ____ rick model of the _____ risk model.

A.  Absolute, relative

B.  Relative, absolute

C.  Stochastic, nonstochastic

D.  Nonstochastic, stochastic

B. Relative, absolute

The linear dose-response model is used to establish radiation protection standards because it accurately reflects the effects of

A.  Both high lenear energy transfer (LET) and low-LET radiations at hight doses.

B.  Both high-LET and low-LET radiations at lower doses.

C.  High-LET radiations at higher doses

D.  Low-LET radiations at lower doses

C.  High-Let radiations at higher doses

The number of excess cancers that would not have occurred in a given population without exposure to ionizing radiation may be predicted by which of the rollowing?

1.  Absolute risk model

2.  Biologic risk model

3.  Relative risk model

A.  1 and 2 only

B.  1 and 3 only

C.  2 and 3 only

D.  1, 2, and 3

B.  1 and 3 only

After the accident at the Chernobyl nuclear power plant in 1986, many children in Poland and some other countries were given potassium iodide to prevent

A.  Breast cancer

B.  Bone cancer

C.  Leukemia

D.  Thyroid cancer

D.  Thyroid cancer

Most radiation-induced genetic mutations are _______________

A.  Dominant mutations

B.  Expressed in first-generation offspring

C.  Spontaneous mutations unique to radiation

D.  Recessive mutations

D.  Recessive mutations

On which of the following factors does somatic or genetic radiation-induced damage depend?

1. Extent of the body area exposed

2. Amount of ionizing radiation to which the subject is exposed

3. Specific parts of the body exposed

A.  1 only

B.  2 only

C.  3 only

D.  1, 2, and 3

D.  1, 2, and 3

When exposure to ionizing radiation causes proliferation of the white blood cells, the radiation-induced disease that occurs is

A.  Anemia

B.  Erythroleukosis

C.  Granulocytopenia

D.  Leukemia

D.  Leukemia

Radiation can induce genetic damage by which of the following means?

A. Interacting with somatic cells of only one parent

B.  Interacting with somatic cells of both parents

C.  Altering the essential base coding sequence of DNA

D.  None of the above; radiation cannot induce genetic damage

C. Altering the essential base coding sequence of DNA

Using the doubling dose concept to measure the effectiveness of ionizing radiation at causng mutations, if 9% of the offspring in each generation are born with mutations in the absence of radiation other than background levels, adminstration of the doubling dose to all members of the population eventually would increase the numbe rof mutations to

A.  18%

B.  36%

C.  72%

D.  100%

A.  18%

What do the atomic bomb survivors of Hiroshima and Nagasaki, the Marshall Islanders inadvertently subjected to high levels of fallout during an atomic bomb test in 1954, and the nuclear radiation victims of the 1986 Chernobyl disaster have in common?

A.  All were exposed to low-level ionizing radiation.

B.  All were expose to high levels of ionizing radiation, but no group members suffered any appreciable bodily damage.

C.  All were exposed to doses of ionizing radiaiton sufficient to cause ARS in many group members.

D.  These groups have nothing in common.

C.  All were exposed to doses of ionizing radiation sufficient to cause ARS in many group members.

For a recessive mutation to appear in an offspring

A.  Both parents must have the same genetic defect.

B.  Both parents must have only dominat genes.

C.  Neither parent needs to have a genetic defect.

D.  Only one parent must hav a genetic defect.

A.  Both parents must have the same genetic defect.

Early (acute) deterministic somatic effects of ionizing radiation are not cause by which of the following?

A. Doses greater than 3 Gy (300 rads)

B. Doses greater than 6 Gy (600 rads)

C. Doses resulting from atomic bomb detonation

D. Doses encountered in diagnostic radiology.

D.  Doses encountered in diagnostic radiology.

All life forms seem to be most vulnerable to radiation

A. During the embryonic stage of development

B. Immediately after birth

C. During early childhood

D. During adolescence

A.  During the embronic stage of development.

Which of the following are examples of stochastic effects?

A. Nausea and vomiting

B. Epilation and fatigue

C. Diarrhea and leukopenia

D. Cancer and genetic defects

D. Cancer and genetic defects

During the embronic stage of development:

A.  All life forms seem to be most vulnerable to radiation exposure.

B.  Only a very small percentage of life forms seem to be vulnerable to radiation exposure.

C.  A significant percentage of life forms seem to be vulnerable to radiation exposure.

D.  Exposure to radiaton cannot damage any life form.

A.  All life forms seem to be most vulnerable to radiation exposure.

Girls who painted watch dials with radium in some factories in New Jersey in the 1920s and 1920s eventually developed which of the following condiations as a consequence of their exposure to radiation?

1.  Osteoporosis

2.  Osteogenic sarcoma

3.  Carcinomas of the epithelial lining of the nasopharynx and paranasal sinuses

A. 1

B. 2

C. 3

D. 1, 2, and 3

D. 1, 2, and 3

Radium decays with a half-life of 1622 years to the radioactive element

A. Uranium

B. Radon

C. Plutonium

D. Americium

B. Radon

Mutant genes cannot properly govern the cell's normal chemical reactions or properly control the sequence of _______ in the formation of specific proteins.

A. Amino acids

B. Enzymes

C. Hormones

D. Peptic acids

A. Amino acids

Which of the following are mutagens?

1. Elevated temperatures

2. Ionizing radiation

3. Viruses

A. 1 and 2 only

B. 1 and 3 only

C. 2 and 3 only

D. 1, 2, and 3

D. 1, 2 and 3

The only concrete evidence that ionizing radiation causes genetic effects comes from

A. Human populations exposed to low radiation doses

B. Human populations exposed to moderate radiation doses

C. Human populations exposed to high radiation doses

D. Extensive experiments with fruit flies and mice at high radiation doses.

D.  Extensive experiments with fruit flies and mice at high radiation doses.

Which of the following led to the development of the doubling dose concept?

A. Animal studies of radiation-induced genetic effects.

B. Human studies of radiation-induced genetic effects.

C. Animal studies of radiation-induced somatic effects.

D. Human studies of radiation-induced somatic effects.

A. Animal studies of radiation-induced genetic effects.

Cataracts, leukemia, and genetic mutations are examples of

A. Diseases that are not caused by ionizing radiation

B. Measurable radiation-induced biologic damage

C. Diseases caused by nonionizing radiation

D. Radiation-induced biologic damage that cannot be measured.

B. Measurable radiation-induced biologic damage

ARS is actually a collection of symptoms associated with

A.  Exposure to low-level radiation

B.  Exposure to moderate-level radiation

C.  Exposure to high-level radiation

D.  Exposure to nonionizing radiations

C. Exposure to high-level radiation

Revised atomic bomb data for Hiroshima and Nagasaki suggest that radiation-induced leukemias and solid tumors in the survivors may be attributed to exposure to which of the following radiations?

A. Alpha particles

B. Beta particles

C. Gamma rays

D. Neutrons

C. Gamma rays

Which of the following groups provide evidence for radiation carcinogenesis?

1. Radium watch dial painters (1920s and 1930s)

2. Early medical radiation workers (1896-1910)

3. Japanese atomic bomb survivors (1945)

A. 1 and 2 only

B. 1 and 3 only

C. 2 and 3 only

D. 1, 2, and 3

D. 1, 2, and 3

In a DNA macromolecule, the sequence of __________ determines the characteristics of every living thing.

A. Sugars

B. Phosphates

C. Nitrogenous organic bases

D. Hydrogen bonds

C. Nitrogenous organic bases

How many base pairs are there in the human genome?

A. 2.58 X 10 to the 4

B. 2.58 X 10 to the -4

C. 2.9 X 10 to the 9

D. 2.9 X 10 to the -9

C.  2.9 X 10 to the 9

Radiation-induced chromosome damage may be evaluated during which of the following processes?

A. Prophase

B. Metaphase

C. Anaphase

D. Telophase

B. Metaphase

If exposure to ionizing radiation damages the components involved in molecular synthesis beyond repair, cells do which of the following?

A. Continue to function normally

B. Function abnormally or die

C. Repair themselves immediately because of the enzymatic proteins they contain

D. Reproduce themselves in pairs

B. Function abnormally ro die

Which of the following produces antibodies?

A. Erythrocytes

B. Lymphocytes

C. Thrombocytes

D. Platelets

B. Lymphocytes

Water constitutes approximately  _____ of the weight of the human body.

A. 30% to 35%

B. 50% to 55%

C. 65% to 70%

D. 80% to 85%

D. 80% to 85%

Which of the following must the human body provide to ensure efficient cell operation?

1. Food as a source of raw material for the release of energy.

2. Oxygen to help break down food

3. Water to transport inorganic substances into and out of the cell.

A. 1 and 2 only

B. 1 and 3 only

C. 2 and 3 only

D. 1, 2, and 3

D. 1, 2, and 3

Which human cell component controls cell division and multiplication as well as biochemical reactions that occur within the cell?

A. Endoplamic reticulum

B. Mitochondria

C. Lysosomes

D. Nucleus

D. Nucleus

What term is used to describe chemical secretions that are manufactured by various endocrine glands and carried by the bloodstream to influence the activities of other parts of the body?

A. Amino acids

B. Antibodies

C. Hormones

D. Disaccharides

C. Hormones

Somatic cells divide through the process of

A. Meiosis

B. Mitosis

C. Mapping

D. Metabolism

B. Mitosis

For radiation protection, high-LET radiation is of greatest concern when a radionuclide has been implanted, ingested, injected, or inhaled because:

A. Only single-strnd breaks in DNA are possible

B. The potential exists for repairable damage of single-strand breaks in DNA

C. The potential exists for irreparable damage because multiple-strand breaks in DNA are possible.

D. The potential exists fore repairable damage in DNA resulting form multiple-strand breaks

C. The potential exists for irreparable damage because multiple-strand breaks in DNA are possible.

Free radicals behave as an extremely reactive single entity as a result of the presence of:

A. paired electrons

B. Unpaired electrons

C. Paired neutrons and protons

D. Unpaired neutrons and protons

B. Unpaired electrons

Which of the following are classified as high-LET radiations?

1. Alpha Particles

2. Gamma rays

3. X-rays

A. 1 only

B. 2 only

C. 3 only

D. 1, 2, and 3

A. 1 only

A biologic reaction is produced by 3 Gy of test radiation.  It takes 12 Gy of 250-kVp x-radiation to produce the same biologis reaction.  What is the relative biologic effectiveness (RBE) f the test radiation?

A. 2.5

B. 3

C. 4

D. 8

C. 4

Which action of ionizing radiation is most harmful to the human body?

A. Direct action

B. Indirect action

C. Epidermiologic action

D. Mitotic action

B. Indirect action

Which molecules in the human body are most commonly directly acted on by ionizing radiation to produce molecular damage through an indirect action?

A. Protein

B. Carbohydrate

C. Fat

D. Water

D. Water

When does ionizing radiation cause complete chromosome breakage?

A. When a single strand of the sugar-phosphate chain sustains a direct hit.

B. When two direct hits occur in the same rung of the DNA macromolecule

C. When two direct hits occur in different runs of the DNA macromolecule

D. When two direct hits are sustained at opposite ends of the DNA macromolecule

B. When two direct hits occur in the same rung of the DNA macromolecule

When significant numbers of lymphocytes are damaged by exposure form ionizing radiation, the body:

1. Loses it natural ability to combat infection

2. Becomes more susceptible to bacteria

3. Becomes more susceptible to viral antigens

A. 1 and 2 only

B. 1 and 3 only

C. 2 and 3 only

D. 1, 2, and 3

D. 1, 2, and 3

With respect to the law of Bergonie and Tribondeau, which of the following would best complete this statement?  "The most pronounced radiation effects occur in cells having the ________".

A. least reproductive activity, shortest mitotic phases, and most maturity.

B. Greatest reproductive activity, shortest mitotic phases, and most maturity.

C. Greatest reproductive activity, longest mitotic phases, and least maturity

D. Least reproductive activity, shortest mitotic phases and lest maturity.

C. Greatest reproductive activity, longest mitotic phases, and least maturity

What do basal cells of the skin, intestinal crypt cells, and reproductive cells have in common?

A.  All cells are hypoxic

B.  All cells are premalignant

C.  All cells are radioinsensitive

D.  All cells are radiosensitive

D.  All cells are radiosensitive

Cancer and genetis defects are examples of ________ effects.

A. Stochastic

B. Nonstochastic

C. Birth

D. Deterministic

A. Stochastic

Lethal dose of ionizing radiation for humans is usually given as:

A. LD 50/30

B. LD 50/60

C. LD 50/90

D. LD 50/120

B. LD 50/60

Which of the following provide the foundation for the sigmoid, or "S-shaped" (nonlinear), threshold curve of radiation dose response?

1.  Data from human population observed after acute high doses of radiation.

2. Dat afrom human populations observed after chronic low doses of radiation.

3. Laboratory experiments on animals

A. 1 only

B. 2 only

C. 3 only

D. 1, 2, and 3

A. 1 only

The linear, nonthreshold curve implies tha biologic response is:

A. Directly proportional to the dose

B. Inversely proportional to the dose

C. Insignificant in relation to dose

D. Not able to be plotted on a dose-response curve

A. Directly proportional to the dose

Acute radiaion syndrome presents in four major response stages.  In what order do these stages occur?

A. Latent period, prodromal, manifest illness, recovery or death

B. Manifest illness, prodromal, latent period, recover or death.

C. Prodromal, latent period, manifest illness, recovery or death.

D. Manifest illness, latent period, prodromal, recovery or death

C. Prodromal, latent period, manifest illness, recovery or death

During the 10 years immediately after the 1986 Chernobyl nuclear power station accident, which of the following was the most pronounced health effect observed?

1.  Dramatic increase inteh incidence of childhood leukemia

2.  Dramatic increase in thyroid cancer in children living in the regions wehre the heavies radioactive contamination occurred.

3.  Major increas in the number of solid tumors in the general population of the former Soviet Union.

A. 1, 2, and 3

B. 1 only

C. 2 only

D. 3 only

C. 2 only

Early demise of the experimental animals exposed to nonlethal doses of ionizing radiation actually resulted from:

A. Accelerated aging

B. Hemorrhage

C. Induction of cancer

D. Respiratory distress

C. Induction of cancer

Which of the following systems is the most radiosensitive vital organ system in human beings?

A. Cerebrovascular

B. Gastrointestinal

C. Hematopoietic

D. Skeletal

C. Hematopoietic

When cells are exposed to sublethal doses of ionizing radiation, approximately ______ of radiation-induced damage may be repaired over time, and about _______ is irreparable.

A. 25%, 75%

B. 50%, 50%

C. 75%, 25%

D. 90%, 10%

D. 90%, 10%