bio 4

_ is a polysaccharide that is found in plant cell walls and accounts for their strength.

• Glucose
• Cellulose
• Fiber
• Starch

One carbon atom can form covalent bonds with up to _ other atoms to form an organic molecule.

• 2
• 4
• 6
• 8

Which of the following statements is true of chemical bonds?

• Chemical bonds are only found in solids
• Chemical bonds repel atoms away from each other
• Covalent bonds share electrons between two atoms.

• Chemical bonds do not involve electrons

Which group of lipids forms a barrier around cells?

• Phospholipids
• Cholesterol
• Steroids
• Triglycerides

The two isotopes shown below differ in the number of
12/6c

• nucleons
• protons
• electrons
• neutrons

You notice that rain water forms "beads" on your car. This is an example of what property of water?

• Adhesion
• cohesion

• Condensation
• Surface tension

The nucleus of an atom contains

• electrons and protons
• protons and neutrons
• neutrons and electrons
• protons and electrons

The isotope shown below has

14/6 c

• 8 neutrons

• Carbon-10
• Carbon-16
• Carbon-12

A hydrogen bond will form between two water molecules when

• the oxygen atom of one water molecule is attracted to the hydrogen atom of another water molecule
• a slightly positive hydrogen on one water molecule becomes attracted to a slightly negative oxygen on another water molecule

• the hydrogen atom of one water molecule is attracted to the oxygen atom of another water molecule
• the hydrogen atom of one water molecule is attracted to the hydrogen atom of another water molecule

Which statement regarding acids and bases is correct?

• Acids increase the proportion of hydrogen ions (H), and bases reduce the proportion of H*.

• Acids release chloride ions (Cl-) in water, while bases release sodium ions (Na+) in water.
• Acids release oxygen ions (O-) in water, while bases release nitrogen ions (N+) in water.
• Acids release hydroxide ions (OH-) in water, while bases release hydrogen ions (H+) in water.