Question

atomic radiation is useful for treating cancer because
a radiation affects cancer cells but not normal cells.
b radiation protects normal cells against the effects of cancer.
c radiation harms cancer cells more readily than it does most non-cancer cells.
d normal cells are not affected by radiation.

question 20

the secondary structure of a protein molecule is the result of
a oxygen double bonds.
b covalent bonds.
c ionic bonds.
d hydrogen bonds.

last saved 10:27:16 am

questions filter (51)

Explanation:

First Question (Atomic Radiation and Cancer Treatment)

• Option A: Radiation does affect normal cells, so this is incorrect.
• Option B: Radiation is used to target cancer, not protect normal cells from cancer effects, so this is incorrect.
• Option C: Radiation therapy works because cancer cells (which divide rapidly) are more susceptible to damage from radiation than most normal cells (which divide more slowly), so this is correct.
• Option D: Normal cells are affected by radiation (though to a lesser extent than cancer cells in many cases), so this is incorrect.

• Option A: Oxygen double bonds are not the main factor in protein secondary structure.
• Option B: Covalent bonds are more involved in primary structure (peptide bonds) and some side - chain interactions, not secondary structure.
• Option C: Ionic bonds are not the primary force behind protein secondary structure.
• Option D: The secondary structure of a protein (e.g., alpha - helices, beta - sheets) is primarily formed by hydrogen bonds between the backbone atoms of the polypeptide chain.

Answer:

C. radiation harms cancer cells more readily than it does most non - cancer cells.

Second Question (Protein Secondary Structure)