Question 1

Which of the following best describes why DNA is considered the molecule of inheritance in all organisms?

Accepted Answer

DNA contains the instructions for building proteins, which are essential for all cellular functions.

Question 2

A scientist is testing the effect of a new fertilizer on plant growth. She sets up two groups: one receives the fertilizer, and the other does not. Which of the following correctly identifies the control group and the independent variable?

Accepted Answer

The group without fertilizer is the control group; the independent variable is the presence of fertilizer.

Question 3

Which of the following is NOT a characteristic of all living things?

Accepted Answer

Ability to photosynthesize

Question 4

Given an atom with atomic number 9 and atomic mass 19, how many neutrons does it have?

Accepted Answer

$$19 - 9 = 10$$ neutrons

Question 5

Which of the following best explains why water is an excellent solvent for ionic compounds?

Accepted Answer

Water is polar, so it can surround and separate ions due to its partial charges.

Question 6

A solution is made by dissolving 10 grams of NaCl (molar mass = $$58.44 \ \mathrm{g/mol}) in $$enough water to make $$500 \ \mathrm{mL} of $$solution. What is the molarity of the solution?

Accepted Answer

$$\frac{10}{58.44} = 0.171 \ \mathrm{mol}$$; $$0.171 \ \mathrm{mol} \div 0.5 \ \mathrm{L} = 0.342 \ \mathrm{M}$$

Question 7

Which of the following statements about the scientific method is correct?

Accepted Answer

A hypothesis can be supported or disproved, but never proven absolutely true.

Question 8

Which of the following best describes the difference between a cation and an anion?

Accepted Answer

A cation has lost one or more electrons and is positively charged; an anion has gained one or more electrons and is negatively charged.

Question 9

Which property of water allows insects to walk on its surface and plants to transport water from roots to leaves?

Accepted Answer

Cohesion and adhesion due to hydrogen bonding

Question 10

A molecule has the formula $$C_6H_{12}O_6$. Which of the following statements is true?

Accepted Answer

It is a molecular formula, which shows the number and type of atoms in the molecule.

Question 11

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Hydrogen bonds in ice hold water molecules farther apart, making ice less dense than liquid water.

Question 12

Which of the following is an example of a buffer in the human body, and what is its function?

Accepted Answer

Bicarbonate; it helps maintain blood pH by neutralizing excess acids or bases.

Question 13

Which of the following functional groups is found in amino acids and acts as a base by accepting hydrogen ions?

Accepted Answer

Amino group $$(-NH_2$)$$

Question 14

Which of the following best describes the difference between a hypothesis and a theory in science?

Accepted Answer

A hypothesis is a testable explanation for a specific observation; a theory is a broad explanation supported by extensive evidence.

Question 15

Which of the following is a correct calculation for the pH of a solution with a hydrogen ion concentration of $$1 	imes 10$$^{-5}$$ \ \mathrm{M}$$?

Accepted Answer

$$\mathrm{pH} = -\log_{10}(1 	imes 10$$^{-5}$$) = 5$$

Question 16

Which of the following is an example of a geometric (cis-trans) isomer?

Accepted Answer

Two molecules with the same molecular formula but different spatial arrangements around a double bond

Question 17

Which of the following best explains why carbon is able to form such a diversity of organic molecules?

Accepted Answer

Carbon has four valence electrons, allowing it to form up to four covalent bonds with other atoms.

Question 18

A student is given a sample of an unknown substance. It dissolves easily in water and has a pH of 2. Which of the following best describes the substance?

Accepted Answer

It is hydrophilic and acidic.

Question 19

Which of the following best describes the difference between prokaryotic and eukaryotic cells?

Accepted Answer

Prokaryotic cells lack a nucleus and membrane-bound organelles; eukaryotic cells have both.

Question 20

Which of the following is the correct order of the hierarchy of biological classification, from most inclusive to least inclusive?

Accepted Answer

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

BIO 1111 Study Guide: Introduction to Biology and Basic Chemistry (Chapters 1-4)

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