Question 1

Which molecule is primarily responsible for directing cellular functions in living organisms?

Accepted Answer

DNA

Question 2

How does the structure of organic molecules influence their biological function?

Accepted Answer

Structure determines how molecules interact and perform specific functions in cells.

Question 3

DNA contains information that is passed from one generation to the next. What is the molecular basis for this inheritance?

Accepted Answer

The sequence of nucleotides in DNA

Question 4

Which of the following best describes the role of DNA in understanding human history?

Accepted Answer

DNA allows us to trace ancestry and migration patterns through genetic information.

Question 5

What type of information does DNA provide to make new cells?

Accepted Answer

Instructions for synthesizing proteins

Question 6

Which process describes how DNA forms a template for its own synthesis?

Accepted Answer

Replication

Question 7

During DNA replication, which bonds are broken to separate the two strands?

Accepted Answer

Hydrogen bonds

Question 8

Which base is found in RNA but not in DNA?

Accepted Answer

Uracil

Question 9

What is the main structural difference between DNA and RNA?

Accepted Answer

DNA is usually double-stranded, RNA is usually single-stranded.

Question 10

Which of the following is a correct complementary base pairing in DNA?

Accepted Answer

Guanine pairs with cytosine

Question 11

Which equation represents the formation of a phosphodiester bond between two nucleotides?

Accepted Answer

$$\mathrm{Nucleotide}_1{-}OH + \mathrm{Nucleotide}_2{-}OH \rightarrow \mathrm{Nucleotide}_1{-}O{-}P{-}O{-}\mathrm{Nucleotide}_2 + H_2O$$

Question 12

Which property makes RNA less stable than DNA?

Accepted Answer

RNA contains a hydroxyl group (-OH) on the 2' carbon of ribose.

Question 13

Which type of RNA carries the genetic instructions from DNA to the ribosome for protein synthesis?

Accepted Answer

mRNA

Question 14

Which of the following is a function of steroids in mammals?

Accepted Answer

Stabilization of membranes and acting as hormones

Question 15

What structural feature distinguishes saturated from unsaturated fatty acids?

Accepted Answer

Saturated fatty acids contain only single bonds between carbon atoms.

Question 16

Which equation best represents the formation of a triglyceride from fatty acids and glycerol?

Accepted Answer

$$\mathrm{Glycerol} + 3~\mathrm{Fatty~acids} \rightarrow \mathrm{Triglyceride} + 3~H_2O$$

Question 17

Why do phospholipids form bilayers in aqueous solutions?

Accepted Answer

Because their hydrophilic heads interact with water and hydrophobic tails avoid water.

Question 18

Which of the following best explains why fats provide more energy per gram than carbohydrates?

Accepted Answer

Fats have more carbon-carbon and carbon-hydrogen bonds, which release more energy when broken.

Question 19

Which property allows some proteins to integrate into lipid bilayers?

Accepted Answer

They are amphipathic, containing both hydrophilic and hydrophobic regions.

Question 20

Which of the following is a real-world application of RNA technology discussed in the study materials?

Accepted Answer

RNA is used to make vaccines, such as those approved for emergency use in the US.

Molecular Basis of Cellular Information: DNA, RNA, and Lipids

Study Guide - Practice Questions