F5 IB Biology 2425 First Term

Which bonds are responsible for the cohesive properties of water molecules?

• Hydrogen bonds between water molecules

• Hydrogen bonds within water molecules

• Covalent bonds between water molecules

• Covalent bonds within water molecules

Which of the following aid in the transfer of water between cells in a leaf and the outside environment?

• Positive pressure in xylem vessels

• Active transport of water from cell to cell

• Capillary action in the cell walls

• Condensation of water on the leaf surface

Which of the following are properties of most enzyme molecules?

• Hydrophobic and insoluble

• Hydrophilic and soluble

• Hydrophobic and soluble

• Hydrophilic and insoluble

Why is water a polar molecule?

• Because it contains hydrogen

• Because hydrogen and oxygen are linked with a covalent bond

• Because there are hydrogen bonds in the water molecule

• Because the electrons in the covalent bond are not shared equally

Why is water a good solvent of ionic substances?

• Positive ions are attracted to the hydrogen atom in water

• Negative and positive ions are attracted to the oxygen atom in water

• Negative ions are attracted to the covalent bonds in water

• Negative and positive ions are attracted to polar water molecules

Predict what would happen if a eukaryotic animal cell was bathed in a hypertonic solution.

• It will shrink.

• It will expand.

• It will burst.

• It will remain the same.

An organ for transplant is bathed in a cooled liquid to be transported to the operating theatre patient. What should be a property of this liquid?

• It is hypotonic to body fluids.

• It is isotonic to body fluids in glucose concentration.

• It is hypertonic to body fluids.

• It is isotonic to body fluids in solute concentration.

Osmosis is the movement of water molecules across a membrane. It requires a membrane in order to:

• Maintain the water potential across the membrane

• Provide protein pumps for water movement

• Allow solute movement out of the cell

• Provide energy to drive osmosis

Carbon is the basis of biological polymers because

I. It can form chains by bonding to other carbon atoms.

II. It is found in carbohydrates.

III. It can form four covalent bonds.

IV. It can form branched and ring structures.

• I only

• I and II only

• I, III, and IV only

• I and III only

Which of the following is the best description of the formation of a triglyceride from glycerol and 3 fatty acids?

• Hydrolysis

• Condensation

• Lysis

• Catabolism