Question 1

When a prediction is made that the number of excess cancers in a given population will increase as the natural incidence of cancer increases in that population with age,the risk is described by which of the following terms?

Accepted Answer

D

Question 2

In general,laboratory experiments with mice prove that cataracts may be induced with doses of ionizing radiation as low as:

Accepted Answer

A

Question 3

Studies of Japanese atomic bomb survivors demonstrate that the incidence of leukemia has ______ since the late 1940s and early 1950s,and the incidence of solid tumors has continued to ______ since the late 1950s and early 1960s.

Accepted Answer

A

Question 4

Mutations in genes and DNA that occur at random as natural phenomena are called:

Accepted Answer

Spontaneous mutations are those that occur naturally and randomly, without any known cause or external influence. They can happen during DNA replication or repair, or as a result of chemical or physical changes in the environment. Deterministic mutations are those that are caused by specific genetic factors or environmental exposures, while sporadic mutations refer to those that occur infrequently or irregularly. Stochastic mutations are a type of spontaneous mutation that are influenced by random chance or probability.

Question 5

The human body can incorporate radium into bone because it is chemically similar to:

Accepted Answer

Radium has similar chemical properties to calcium, so it can be incorporated into bone tissue in the same way that calcium is.

Question 6

Which of the following groups of people exposed to ionizing radiation provide proof that low-level radiation exposure produces late effects?

Accepted Answer

The answer of Which of the following groups of people...

Question 7

For an accurate estimate of the number of radiation-induced leukemias and other malignancies that may occur in some of the 135,000 evacuees from the 1986 nuclear power station accident in Chernobyl,Ukraine,the exposed population must _______.

Accepted Answer

Long-term monitoring is necessary to accurately estimate the number of radiation-induced leukemias and other malignancies that may occur in the exposed population. This monitoring can provide information on the incidence and types of cancers that develop over time, allowing for better predictions of future health outcomes.

Question 8

Of the following late effects caused by exposure to ionizing radiation,which effect is considered to be most important?

Accepted Answer

Cancer is considered to be the most important late effect caused by exposure to ionizing radiation because it can lead to serious health consequences, including death. Cataract formation and embryologic or birth defects are also important, but they are generally not life-threatening.

Question 9

Radiation-induced abnormalities are caused by unrepaired damage to:

Accepted Answer

Radiation-induced abnormalities are caused by damaging DNA within ova or sperm. This damage can then be passed on to future generations, resulting in birth defects or genetic disorders.

Question 10

Uranium miners in the Colorado plateau who developed lung cancer years after exposure provide an example of which of the following?

Accepted Answer

The development of lung cancer in uranium miners years after exposure is an example of a late stochastic effect, which means the likelihood of developing cancer increases with the amount of radiation exposure but there is no threshold level below which the risk is zero.

Question 11

After the 1986 nuclear power station accident in Chernobyl,Ukraine,an attempt was made to prevent thyroid cancer in children in Poland and some other countries as a consequence of accidental overdose of iodine-131; _______________ was administered as a substitute for take-up of iodine-131.

Accepted Answer

To prevent thyroid cancer caused by iodine-131, a radioactive byproduct from nuclear accidents, potassium iodide is administered as a substitute. This is because the thyroid gland readily absorbs iodine, including radioactive forms such as iodine-131. By saturating the thyroid with stable iodine in the form of potassium iodide, uptake of radioactive iodine is reduced, thereby decreasing the risk of thyroid cancer.

Question 12

During the preimplantation stage of development,a radiation dose of 0.05 to 0.15 Gyt delivered to a human fertilized ovum will result in which of the following?

Accepted Answer

A radiation dose of 0.05 to 0.15 Gyt delivered during the preimplantation stage of development will most likely result in embryonic death, as the fertilized ovum is highly sensitive to radiation during this stage. Congenital abnormalities, delayed bone growth, and microcephaly are more likely to occur with higher doses of radiation delivered during later stages of development.

Question 13

Radiation-induced cataracts in humans follow a ______ dose-response relationship.

Accepted Answer

The answer of Radiation-induced cataracts in humans follow a ______...

Question 14

Existing data on radiation-induced genetic effects in humans :

Accepted Answer

Existing data on radiation-induced genetic effects in humans are still inconclusive. While there have been studies showing an increased risk of genetic disorders among populations exposed to radiation, it is difficult to determine the exact contribution of radiation to these effects due to other confounding factors such as lifestyle and environmental exposures. Additionally, the long latency period for many genetic disorders makes it challenging to link them definitively to radiation exposure.

Question 15

Radiation dose-response curves can be used to predict the risk of ______________ in human populations that have been exposed to low levels of ionizing radiation.

Accepted Answer

Radiation dose-response curves are used to predict the risk of malignancy (cancer) in populations exposed to low levels of ionizing radiation. The curve shows the relationship between the radiation dose and the probability of developing cancer, with higher doses resulting in higher probabilities of cancer. While radiation can also cause cataract formation, genetic effects, and spontaneous abortions, the dose-response curve is most commonly used to evaluate the risk of cancer.

Question 16

Normally,mutations in genetic material occur spontaneously,without a known cause.A genetic disorder is present in approximately _______ of all live births in the United States.

Accepted Answer

The answer of Normally,mutations in genetic material occur spontaneously,without a...

Question 17

Genetic effects from exposure to ionizing radiation occur as a result of radiation-induced damage to the DNA molecule in which of the following?
1)Sperm of a man
2)Ova of a woman
3)Somatic cells of men and women

Accepted Answer

Genetic effects from exposure to ionizing radiation occur due to damage to the DNA in the germ cells, which are the sperm in men and the ova in women. Somatic cells, when mutated, can lead to cancer but do not contribute to hereditary changes.

Question 18

What is the mean value of the radiation doubling equivalent dose for humans,as determined from the children of the atomic bomb survivors of Hiroshima and Nagasaki?

Accepted Answer

The mean value of the radiation doubling equivalent dose for humans, as determined from the children of the atomic bomb survivors of Hiroshima and Nagasaki, is approximately 1.56 Sv. This was found through the study of the health effects on the children of the survivors who were exposed to radiation while in utero. It is important to note that this dose is an estimate and may vary based on individual circumstances and exposure levels.

Question 19

In which of the following human populations is the risk for causing a radiation-induced cancer not directly measurable?
1)All patients in diagnostic radiology subjected to a radiation dose below 0.1 Sievert
2)Chernobyl radiation accident victims living in contaminated villages
3)Japanese atomic bomb survivors

Accepted Answer

The answer of In which of the following human populations...

Question 20

What do agents such as chemicals,elevated temperatures,ionizing radiation,and viruses have in common?

Accepted Answer

Agents such as chemicals, elevated temperatures, ionizing radiation, and viruses are all mutagens that can increase the frequency of occurrence of mutations.

Quiz 9: Late Deterministic and Stochastic Radiation Effects on Organ Systems