Question 1

Which of the following factors increases the electronegativity of an atom?

Accepted Answer

A smaller atomic radius and more protons in the nucleus

Question 2

Given the following elements: Li, Be, B, C, N, O, F, which has the highest electronegativity and why?

Accepted Answer

F, because it has the most protons and the smallest atomic radius

Question 3

Which chemical group is responsible for making a molecule act as an acid by donating a hydrogen ion ($$H^+$$)?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 4

A protein's secondary structure is stabilized primarily by which type of bond?

Accepted Answer

Hydrogen bonds between atoms of the polypeptide backbone

Question 5

Which of the following best describes the difference between DNA and RNA?

Accepted Answer

DNA is usually double-stranded and contains deoxyribose, while RNA is usually single-stranded and contains ribose

Question 6

Which functional group is most likely to form hydrogen bonds with water, increasing a molecule's solubility?

Accepted Answer

Alcohol group ($$-OH)$$

Question 7

Which of the following statements about hydrolysis is correct?

Accepted Answer

Hydrolysis adds a water molecule to break a polymer into monomers

Question 8

Which of the following is NOT a true polymer?

Accepted Answer

Fatty acids

Question 9

A molecule with the formula $$C_6H_{12}O_6$ is most likely a:

Accepted Answer

Carbohydrate

Question 10

Which of the following carbon skeleton variations would result in a branched molecule?

Accepted Answer

2-Methylpropane (isobutane)

Question 11

Which chemical group is responsible for stabilizing protein structure through cross-linking?

Accepted Answer

Thiol group ($$-SH)$$

Question 12

Which of the following best explains why fats are used for long-term energy storage in animals?

Accepted Answer

Fats have a higher energy density and are lighter in weight compared to carbohydrates

Question 13

Which of the following is a correct statement about the structure of DNA?

Accepted Answer

Adenine pairs with thymine via two hydrogen bonds

Question 14

Which of the following is a property of the phosphate group ($$-$$OPO_3$$^{2-}) in $$biological molecules?

Accepted Answer

It contributes negative charge and can confer reactivity to molecules

Question 15

Which of the following best describes a quaternary protein structure?

Accepted Answer

The association of two or more polypeptide chains

Question 16

Which of the following is a correct comparison between carbohydrates and lipids?

Accepted Answer

Carbohydrates have a $$C:H:O$$ ratio of approximately $$1:2:1$$, while lipids have less oxygen

Question 17

Which of the following is a real-world application of the methylated group ($$-CH_3$) in biology?

Accepted Answer

It affects the expression of genes when bonded to DNA

Question 18

Which of the following statements about nucleic acids is correct?

Accepted Answer

Nucleic acids are polymers made of nucleotides

Question 19

Which of the following best explains why cellulose is rigid and strong?

Accepted Answer

It forms long, unbranched chains that hydrogen bond to each other

General Biology Review: Atomic Structure, Chemical Bonds, and Biological Molecules (Classes 1–4)

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