1. 1. Which statement best describes a difference between prokaryotic cells and eukaryotic cells?
a. The presence of both DNA and ribosomes in prokaryotic cells indicates that they are more complex than eukaryotic cells.
b. The larger size of prokaryotic cells indicates than they are more complex than eukaryotic cells.
c. The presence of membrane-bound organelles in eukaryotic cells indicates that they are more complex than prokaryotic cells.
d. The larger size of eukaryotic cells indicates than they are more complex than prokaryotic cells.

2. c. The presence of membrane-bound organelles in eukaryotic cells indicates that they are more complex than prokaryotic cells.

3. 2. Ribosome : protein synthesis :: nucleus :
a. Controlling cell activities.
b. energy release.
c. nutrient storage.
d. protein transport.

4. a. Controlling cell activities.

5. 3. According to the cell theory,
a. the smallest unit of life is a nucleus.
b. animals but not plants are composed of cells.
c. a multicellular organism is composed of many cells.
d. new cells arise only from pre-existing cells.

6. d. new cells arise only from pre-existing cells.

7. 4. Which is not a correct association of organelles and functions?
a. Lysosome – intracellular digestion
b. Cell wall – regulation of molecule passage in and out of animal cells
c. Vacuole – storage
d. Golgi apparatus (bodies) – packing materials for transport

8. b. Cell wall – regulation of molecule passage in and out of animal cells

9. 5. If an active cell produces a material that will later be sent out of the cell, which is the correct sequence of organelles through which that material would travel?
a. ER  ribosomes  golgi apparatus
b. Ribosome  ER  golgi apparatus
c. ER  golgi apparatus  ribosome
d. Golgi  ER  ribosome

10. b. Ribosome  ER  golgi apparatus

11. 6. Both plant and animal cells have mitochondria because they both
a. carry out photosynthesis.
b. have a large central vacuole.
c. have endoplasmic reticulum.
d. need ATP for energy.

12. d. need ATP for energy.

13. 7. Considering the history of microscopy, which of these organelles would have been discovered first?
a. Ribosome
b. Nucleus
c. Lysosome
d. ER

14. b. Nucleus

15. 8. Considering the measures of surface area and volume, explain why our bodies are composed of trillions of very small cells rather than a few hundred very large cells.

16. Cells must be efficient units that transport molecules in and out of cells. Molecules like glucose (which is used for energy) must be imported into the cell quickly so that the cell can use it for energy. Cells must also be able to rid itself of waste products quickly such as CO2. Small cells transport molecules in and out more efficiently than large cells.
A large cell might starve or be poisoned if it can’t take in enough nutrients or get rid of waste fast enough.

17. 9. Besides the mitochondria, identify one similarity and two differences between plant and animal cells.

18. Similarities: Plant and animal cells share most of the same organelles: including ribosomes, ER, mitochondria, and golgi apparatus.
Differences: Plant cells contain a cell wall (for protection) and chloroplasts (for photosynthesis); plants have one larger vacuole to store water and pigments for photosynthesis; animals have several small vacuoles; animals have centrioles, plants do not

19. 10. Explain why complex organisms tend to be multicellular as opposed to unicellular.

20. Complex organisms are multicellular because multicellular organisms often have differentiated cells, which allows organisms to complete varied, complex, differentiated tasks. Unicellular organisms have one cell that must perform all functions for the organism.