Question 1

Which property of carbon is primarily responsible for the molecular diversity observed in living organisms?

Accepted Answer

Carbon can form four covalent bonds, allowing it to create large, complex, and varied molecules.

Question 2

Stanley Miller's 1953 experiment demonstrated that organic molecules could be synthesized abiotically. Which of the following best explains why no organic compounds were found in his control experiment without electrical sparks?

Accepted Answer

The electrical sparks provided the energy needed to drive chemical reactions that formed organic molecules.

Question 3

Which of the following best describes a structural isomer?

Accepted Answer

Molecules with the same molecular formula but different covalent arrangements of their atoms.

Question 4

A molecule with the formula $$C_5H_{12}$$ can exist as three different isomers. What is the main reason for this?

Accepted Answer

Carbon skeletons can vary in length and branching, leading to different covalent arrangements.

Question 5

Which functional group is most likely to make an organic molecule behave as a base?

Accepted Answer

Amino group ($$-NH_2$)

Question 6

Which of the following best explains why fats are hydrophobic?

Accepted Answer

They consist mostly of nonpolar carbon-hydrogen bonds, which do not interact well with water.

Question 7

A dehydration reaction is used to synthesize a polymer from monomers. Which of the following equations correctly represents the number of water molecules released when $$n$$ monomers are joined to form a polymer?

Accepted Answer

$$n-1$$

Question 8

Which of the following statements about cellulose and starch is correct?

Accepted Answer

Both are composed of glucose monomers, but only starch can be digested by most animals because of the type of glycosidic linkage.

Question 9

Which of the following best describes the structure of a phospholipid in a cell membrane?

Accepted Answer

A glycerol molecule joined to two fatty acids and a phosphate group, forming a hydrophilic head and hydrophobic tails.

Question 10

Which of the following is a direct consequence of the specific sequence of amino acids in a polypeptide?

Accepted Answer

The protein's three-dimensional structure and function.

Question 11

A single amino acid substitution in the primary structure of hemoglobin can cause sickle-cell disease. Which property of the substituted amino acid is most responsible for the altered function?

Accepted Answer

Its hydrophobicity, which causes abnormal aggregation of hemoglobin molecules.

Question 12

Which of the following best describes the relationship between DNA, RNA, and protein in the process of gene expression?

Accepted Answer

DNA is transcribed into RNA, which is then translated into protein.

Question 13

Which of the following base sequences could form a short stretch of a normal double helix of DNA?

Accepted Answer

$$5'	ext{-}AGCT	ext{-}3'$$ with $$5'	ext{-}TCGA	ext{-}3'$$

Question 14

Which of the following best explains why only one enantiomer of a drug may be biologically active?

Accepted Answer

Only one enantiomer fits the specific shape of the target molecule in the body.

Question 15

Which of the following is a function of the methyl group ($$-CH_3$) in biological molecules?

Accepted Answer

It serves as a recognizable tag that affects gene expression.

Question 16

Which of the following best describes the role of ATP in cellular processes?

Accepted Answer

ATP stores energy in its phosphate bonds and releases energy when it reacts with water to form ADP and inorganic phosphate.

Question 17

Which of the following statements about genomics is correct?

Accepted Answer

Genomics is the study of the entire set of genes and their interactions within and between species.

Question 18

Which of the following best explains why the human genome is more similar to that of a chimpanzee than to a mouse?

Accepted Answer

Humans and chimpanzees share a more recent common ancestor than humans and mice.

Carbon and the Molecular Diversity of Life & The Structure and Function of Large Biological Molecules

Study Guide - Practice Questions

Study Guide - Flashcards