Date: Name: Class

DATE: NAME: CLASS:

BLM 9-8

ASSESSMENT Unit 3 Test Key

Goal • Demonstrate your understanding of the information presented in Unit 3.

Multiple Choice

Circle the letter for the choice that best completes the statement or answers the question.

1. Which type of cell or cell organelle does not have a high surface area-to-volume ratio?

(a) plant root hairs

(b) Golgi apparatus

(d) vacuole

2. Which organelle produces proteins?

(a) nucleus

(b) lysosome

(d) vacuole

3. What kind of environment occurs when the concentration of dissolved substances is greater outside the cell

than inside the cell?

(a) hypotonic

(b) hypertonic

(d) saline

4. An amoeba ingests large food particles by

(a) osmosis

(b) diffusion

(d) exocytosis

5. In the surface area-to-volume ratio, what structure does the surface area represent?

(a) cytoplasm

(b) mitochondria

(d) plasma membrane

6. What is a main idea of the cell theory?

(a) All cells have a plasma membrane.

(b) All cells come from pre-existing cells.

(d) All cells are made of atoms.

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DATE: NAME: CLASS:

BLM 9-8

ASSESSMENT Unit 3 Test (continued)

7. A three-dimensional image of the interior of a specimen can be viewed with a

(a) compound light microscope

(b) scanning electron microscope

(d) scanning tunnelling microscope

8. A ribosome

(a) does not have a cell wall

(b) is not surrounded by a membrane

(d) all of the above

9. Which structure is found in rough endoplasmic reticulum but not in smooth endoplasmic reticulum?

(a) ribosomes

(b) cytoplasm

(d) mitochondria

10. The small size of cells is best correlated with

(a) the fact that they are self-reproducing

(b) their prokaryotic versus eukaryotic nature

(d) their vast versatility

11. Vesicles from the smooth endoplasmic reticulum are most likely on their way to the

(a) rough endoplasmic reticulum

(b) lysosomes

(d) plant cell vacuole

12. Lysosomes function in

(a) protein synthesis

(b) processing and packaging

(d) all of these are correct

13. The fluid-mosaic model of membrane structure refers to

(a) the fluidity of proteins and the pattern of phospholipids in the membrane

(b) the fluidity of phospholipids and the pattern of proteins in the membrane

(d) the lack of fluidity of internal membranes compared with the plasma membrane, and the ability of proteins

to move laterally in the membrane

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DATE: NAME: CLASS:

BLM 9-8

ASSESSMENT Unit 3 Test (continued)

14. A phospholipid molecule has a head and two tails. Where are the tails found?

(a) at the surfaces of the membranes

(b) in the interior of the membrane

(d) where the environment is hydrophilic

15. A scientist who is observing a protozoan notices a vacuole discharging its contents at the cell membrane. This

is an example of

(a) phagocytosis and vacuole formation

(b) endocytosis and active transport

(d) active transport and vacuole release

16. When are stomata usually open?

(a) at night, when the plant requires a supply of oxygen

(b) during the day, when the plant requires a supply of carbon dioxide

(d) all of the above

17. What is the role of transpiration in water and mineral transport?

(a) Transpiration causes water molecules to be cohesive and cling together.

(b) Transpiration occurs in vessel elements but not in the tracheids that have end walls.

(d) Transpiration creates the tension that draws a column of water up the vessel elements.

18. Root hairs do not play a role in

(a) oxygen uptake

(b) mineral uptake

(d) carbon dioxide uptake

19. Which statement is correct?

(a) Both stems and roots show positive gravitropism.

(b) Both stems and roots show negative gravitropism.

(d) Only roots show positive gravitropism.

20. Which process can move molecules against a concentration gradient?

(a) diffusion

(b) active transport

(d) osmosis

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DATE: NAME: CLASS:

BLM 9-8

ASSESSMENT Unit 3 Test (continued)

21. Which type of cell is non-living at maturity?

(a) guard cells

(b) epidermal cells in roots

(d) sieve cells

22. What happens at lenticels?

(a) gas exchange

(b) water absorption

(d) phototropism

23. The liquid in the phloem contains 10 to 25 percent dissolved solid matter. This solid matter is primarily

(a) starch

(b) sucrose

(d) lipids

24. If you wanted to increase the turgor pressure in a plant inside your home, you would

(a) move the plant to a dark room

(b) add essential nutrients to the soil

(d) add salt water to the soil

Short Answer

Answer each question in the space provided. Be sure to use complete sentences.

25. How would you expect the number of mitochondria in a cell to be related to the amount of active transport the

cell carries out?

26. Explain the part of the cell theory that is credited to each scientist.

(a) Theodor Schwann

The cell is the unit of structure, physiology, and organization in living things.

2) The cell retains a dual existence as a distinct entity and a building block in the construction of organisms.

(b) Rudolf Virchow

"All cells only arise from pre-existing cells".

Was the first to observe protazoa and bacteria using magnification.

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DATE: NAME: CLASS:

BLM 9-8

ASSESSMENT Unit 3 Test (continued)

27. Compare the expected rates of water movement in xylem tissues during the day and during the night.

Due to transpiration, water movement in the xylem would be greater during the day as compared to the night. The evaporation of water from the leaves of the plant would cause water to be drawn up through the xylem at a greater rate.

28. What would happen to a cell if its cell membrane were permeable rather than semi-permeable?

A cell which had a permeable rather than semi-permeable membrane, would probably cease to function due to toxins coming into the cell or vital components leaving the cell or extreme loss or gain of fluid volume.

29. (a) What is the function of leaf epidermis, and how does the structure suit the function?

The epidermis prevents water loss in the leaf. The cuticle layer , which is waxy, helps prevent evaporation from the leaf. The thickness of the epidermis also allows it to function as a successful barrier to evaporation.

(b) What is the function of the spongy tissue cells, and how does the structure suit the function?

The spongy cells are photosynthetic which means they provide energy for the plant.

Leaf veins help distribute nutrients to the various living cells within the leaf. Their branching structure helps to distribute the nutrients to all the different areas of the leaf.