Unit 2 Lesson 1: Properties of Water
1. D – Adhesion and Cohesion are caused by
hydrogen bonds. Hydrogen bonds are
formed because of polar covalent bonds
between the oxygen and hydrogen's atoms
in a water molecule.
2. A – Water is less dense when it freezes,
therefore ice floats.
3. A – Cohesion holds the droplets together
and adhesion holds them onto the pine
needles.
Unit 2 Lesson 1: Properties of Water
4. C – Water absorbs heat when it changes from
a liquid to a vapor.
Unit 2 Lesson 1: Properties of Water
• Part A Answer:
A combination of cohesion and
adhesion contribute to capillary action
within the xylem. The transport of
water begins when water evaporates
from inside the leaf. Due to cohesion,
adjacent water molecules are pulled
upwards along re-placing the
evaporated molecules. The adhesion of
water molecules to plant cell walls
helps water to resist the downward pull
of gravity holding it in place in the
xylem.
Unit 2 Lesson 1: Properties of Water
• Part B Answer:
Cavitation, the formation of air
bubbles within the xylem separates
the water molecules. The water
molecules below the cavitation bubble
can no longer create hydrogen bonds
with the molecules above the
cavitation bubble. So when the
molecule are pulled upward through
the xylem, the molecules below the
cavitation bubble are left behind.
Unit 2 Lesson 2: Organic Molecule
1. A – Carbon can form 4 covalent
bonds.
2. D – Wax, saturated fat and
phospholipids are all lipids.
Polysaccharide is a carbohydrate.
3. C – Dehydration synthesis joins
monomers to create polymers while
releasing a water molecule for each
monomer joined. Glucose is a
monomer.
4. D – it is a phospholipid. Region 2 is
the fatty acid chain which is
nonpolar.
Unit 2 Lesson 2: Organic Molecule
• Part A Answer:
A fat or oil molecule consists of three fatty acid
chains joined to a single molecule of glycerol. The
fatty acid chains are almost entirely hydrogen and
carbon.
Unit 2 Lesson 2: Organic Molecule
• Part B Answer:
Carbohydrates have a 1:2:1 ratio of carbon hydrogen
and oxygen. Lipids are mostly carbon and hydrogen.
Monomers of carbohydrates can be connected
together to form long chains. Lipids to not have a
monomer form.
Unit 2 Lesson 2: Organic Molecule
• Part C Answer:
Fats and carbohydrates store energy for the
organism. They can be broken down by cells to
provide ATP.