Question 1

Which of the following correctly ranks the electronegativity of the most common elements in living organisms from strongest to weakest?

Accepted Answer

O \u003e N ≈ H

Question 2

A water molecule is able to dissolve salt (NaCl) but not oil. Which property of water explains this phenomenon?

Accepted Answer

Water is polar and can interact with charged ions, but oil is nonpolar and cannot form such interactions.

Question 3

Which type of chemical bond is formed by the equal sharing of electrons between atoms with similar electronegativity?

Accepted Answer

Nonpolar covalent bond

Question 4

Why do coastal climates tend to have more moderate temperatures compared to inland areas?

Accepted Answer

Water's hydrogen bonds give it a high heat capacity, absorbing and releasing heat slowly.

Question 5

Which of the following best describes a hydrogen bond?

Accepted Answer

A bond formed by electrical attraction between a partially positive hydrogen and a partially negative oxygen or nitrogen.

Question 6

Which property of water allows a leaf to float on the surface of a pond?

Accepted Answer

Water has high surface tension due to hydrogen bonding.

Question 7

What is the relationship between pH and proton ($$H^+) $$concentration?

Accepted Answer

As pH decreases, proton concentration increases.

Question 8

Which equation correctly expresses the relationship between pH and hydrogen ion concentration?

Accepted Answer

$$\mathrm{pH} = -\log_{10}[H^+]$$

Question 9

A solution with pH 6 is how many times more acidic than a solution with pH 8?

Accepted Answer

100 times

Question 10

Which of the following is a correct description of a nucleotide, the subunit of nucleic acids?

Accepted Answer

A nucleotide consists of a phosphate group, a nitrogenous base, and a five-carbon sugar.

Question 11

Which type of chemical bond holds the nucleotide subunits together in a DNA strand?

Accepted Answer

Phosphodiester bonds

Question 12

Which of the following statements about DNA and RNA is correct?

Accepted Answer

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

Question 13

Which property of water is most important for cooling off animals through sweating or panting?

Accepted Answer

Water's high heat of vaporization

Question 14

Which of the following best explains why water is an excellent solvent for biochemical reactions in cells?

Accepted Answer

Water is polar and can dissolve both ionic and polar substances.

Question 15

Which of the following is true about acids and bases?

Accepted Answer

An acid is a compound that donates a proton ($$H^+$$), while a base accepts a proton.

Question 16

Which of the following is a polymer made of nucleotide monomers?

Accepted Answer

Nucleic acid

Question 17

Which of the following best describes the difference between hydrogen bonds and covalent bonds?

Accepted Answer

Hydrogen bonds are weak electrical attractions between partial charges, while covalent bonds involve sharing of electrons.

Question 18

Which of the following is NOT a major type of biological macromolecule found in cells?

Accepted Answer

Vitamins

Question 19

Which of the following statements about the pH scale is correct?

Accepted Answer

A solution with pH 7 is neutral.

Question 20

Which of the following is a real-life consequence of water's hydrogen bonding?

Accepted Answer

Water moderates coastal climates by absorbing and releasing heat slowly.

Chemical Bonds, Water Properties, and Nucleic Acids in Biology

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