Homework Assignment Chapter 7

Question 1

The principal radiation interaction within the human body is with ______________.

a.) DNA
b.) macromolecules
c.) water
d.) RNA

Answer 1

c.) water

Question 2

A protracted dose of radiation is given:

a.) over a long period of time
b.) all at one short exposure
c.) in a series of seperate doses
d.) in two large doses

Answer 2

a.) over a long period of time

Question 3

The most radiosensitive cells in the hemopoietic system of the human body are the ___________.

a.) granulocytes
b.) erythrocytes
c.) lymphocytes
d.) platelets

Answer 3

c.) lymphocytes

Question 4

The probability of a hit is increased with ___________ oxygen and ______________LET radiation.

a.) high, low
b.) low, low
c.) high, high
d.) low, high

Answer 4

c.) high, high

Question 5

When an atom of water is irradiated, it first dissociates into

a.) two water atoms
b.) an ion pair
c.) free radicals
d.) hydrogen peroxide

Answer 5

b.) ion pair

Question 6

A type of DNA damge that may not be reversible is:

a.) cross linking
b.) base change or loss
c.) rung breakage
d.) severed side rail

Answer 6

b.) base change or loss

Question 7

The possible beneficial effect of a small amount of radiation is called ______________.

a.) radiosensitizing
b.) hormesis
c.) radioprotection
d.) protraction

Answer 7

b.) hormesis

Question 8

Tissues that are ___________ with a __________ metabolic rate are more radiosensitive.

a.) immature, low
b.) immature, high
c.) mature, low
d.) mature, high

Answer 8

b.) immature, high

Question 9

According to target theory, the target molecule of a cell is:

a.) any molecule in the cell
b.) the DNA in the nucleus
c.) a water molecule
d.) a protein macromolecule

Answer 9

b.) the DNA in the nucleus

Question 10

The dissassociation of water molecules following irradation is termed ____________.

a.) radiolysis
b.) ionization
c.) cross linking
d.) point mutation

Answer 10

a.) radiolysis

Question 11

The law of __________ states that the radiosensitivity of living tissue is a funtion of the metabolism and maturation of that tissue.

a.) watson and crick
b.) roentgen and plank
c.) hurter and driffield
d.) bergonie and tribondeau

Answer 11

d.) bergonie and tribondeau

Question 12

The process of cell meiosis results in cells with ___________ chromosomes each.

a.) 22
b.) 23
c.) 46
d.) 48

Answer 12

b.) 23

Question 13

The LD50/60 is the dose of radiation to the whole body that will result in death within _________ to _______% of the irriadated population.

a.) 50 days, 60
b.) 60 days, 50
c.) 60 minutes, 50
d.) 50 minutes, 60

Answer 13

b.) 60 days, 50

Question 14

The indirect interaction of matter with photon energy involves the absorption of radiation within a ___________.

a.) water molecule
b.) glucose molecule
c.) complex protein
d.) alpha particle

Answer 14

a.) water molecule

Question 15

LET is defined as the:

a.) the capability of a specified radiaiton to produce a particular biologic response
b.) increased sensivity of cells, tissues and organs in an aerated enviroment
c.) amount of energy deposited per unit length of path travel
d.) the ionization process

Answer 15

c.) amount of energy deposited per unit length of path travel

Question 16

As LET increases, RBE

a.) increases
b.) decreases
c.) remains the same
d.) LET and RBE are not interdependent

Answer 16

a.) increases

Question 17

Direct action is more likely to occur with:

a.) low LET
b.) high LET
c.) sparsely, ionizing
d.) high energy

Answer 17

b.) high LET

Question 18

Which of the following is a cellular effect of exposure to ionizing radiation

a.) instant death
b.) mitotic delay
c.) genetic death
d.) all of the above
e.) none of the above

Answer 18

d.) all of the above

Question 19

Meiosis is the process of cell divisionn for __________ cells.

a.) muscle
b.) skin
c.) somatic
d.) genetic

Answer 19

d.) genetic

Question 20

Free radicals can cause biologic damage by destroying the chemical bonds of molecules and by dislodging electrons from their orbits. How long will this process continue?

a.) forever
b.) until the energy reaches half of the initial energy
c.) until the energy is lower than the energy of molecules they contact
d.) until all the enrgy is expended

Answer 20

d.) until all the energy is expended

Question 21

What is the DNA messenger?

a.) tRNA
b.) mRNA
c.) ribosome
d.) centrosome
e.) all of the above

Answer 21

b.) mRNA

Question 22

Where is the master molecule located?

a.) generally in the cytoplasm
b.) always in the nucleus
c.) anywhere within the cell
d.) always in the cytoplasm

Answer 22

b.) always in the nucleus

Question 23

Cell division by spindle formation, the duplication of chromosomes, seperation of daughter chromatids, division of cytoplasm, formation of two identical daughter cells ( each with 46 chromosomes) is called:

a.) meiosis
b.) mitosis
c.) halitosis
d.) metaphase

Answer 23

b.) mitosis

Question 24

Which of the following is not a nitrogenous organic base?

a.) protein
b.) adenine
c.) guanine
d.) thymine
e.) cytosine

Answer 24

a.) protein

Question 25

How do free radicals destroy chemicals bonds?

a.) they transfer their excess energy to the molecules
b.) they recombine to form a molecule of water
c.) they form secondary hyrdoxyl
X d.) all of the above
e.) none of the above

Question 26

Any chromosome damage induced by radiation could be seen during the ___________.

a.) metaphase
b.) telophase
c.) anaphase
d.) prophase

Answer 26

a.) metaphase

Question 27

How does human tissue or an organ in the body survive high doses of ionizing radiation?

a.) atrophy
b.) repair of damaged cells
c.) repopulation of lost cells
d.) all of the above
e.) answers b and c only

Answer 27

e.) answers b and c only

Question 28

Which of the following would be considered radiosensitive under the law of bergonie and tribondeau
1.) primitive cells
2.) rapidly dividing cells
3.) cells that expected to divide for a short time

a.) 1 and 2 only
b.) 1 and 3 only
c.) 2 and 3 only
X d.) 1, 2 and 3

Question 29

Organic compounds contain

a.) phospherus
b.) nitrates
c.) k
d.) carbon

Answer 29

d.) carbon

Question 30

Which of the following acts as a resevoir for long term energy storage, insulates and protects the body from the enviroment

a.) proteins
b.) carbohydrates
c.) lipids
d.) nucleic acids

Answer 30

c.) lipids