Download Chapter 7 * A Tour of the Cell * Homework

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Chapter 6 Guided Reading
1. How have microscopes contributed to the study of biochemistry?
2. Biologists use the TEM, SEM and LM to study cells. What are the advantages and
disadvantages of each type of microscope?
3. In one episode of the original Star Trek series, the starship Enterprise was fighting a
space-ship sized single celled organism. In another episode, crew members were
attacked by single cells the size of dinner plates. Describe for the non-biologist why
these episodes are clearly “science fiction”.
4. What cell structures are common to both prokaryotic and eukaryotic cells?
5. Label the prokaryotic cell below – list structure and function.
6. Contrast and compare mitochondria and chloroplasts.
7. Why are mitochondria and chloroplasts not considered part of the endomembrane system?
8. What evidences exist that support the endosymbiotic theory that mitochondria and
chloroplasts used to be independent cells in their own right?
9. How does the structure of microtubules allow them to apparently move from one location of a
cell to another?
10. When the cytoskeleton was first discovered, scientists thought what they were seeing were
artifacts of the TEM. Why shouldn’t they have been surprised to find the cytoskeleton?
(e.g. why is a cytoskeleton necessary for cells).
11. How are the cell walls of plants and bacteria similar, yet different?
12. Which would you rather have hit you; an object made of plant cells with primary cell walls
or an object made of plant cells with secondary walls? Explain
13. Several years ago, a meteorite was found to be from Mars. Upon SEM examination, objects
that looked like prokaryotic cells were found in the interior. This discovery caused a major
splash in the scientific community. Why?
14. The structure of cilia and flagella are the same in all eukaryotic cells? Discuss how this
most likely happened.
15. For each of the structures below – note the specific structure and the function of the
organelle or part of the organelle. The important concept is to note how the specific
structure allows for the specific function to be accomplished.
a. Nucleus
i. Nuclear envelope
ii. Nuclear lamina
iii. Chromosomes
iv. Chromatin
v. Nucleolus
b. Ribosomes
c. Endoplasmic reticulum
i. Smooth ER
ii. Rough ER
d. Golgi Apparatus
e. Lysosomes
f. Vacuoles
i. Food
ii. Contractile
iii. Central w/tonoplast
g. Endomembrane system – overall
h. Plastids
i. Amyloplast
ii. Chromoplast
iii. Chloroplast
1. thylakoids
2. stroma
i. peroxisomes
j. cytoskeleton – pay careful attention to the details in this section
i. microtubules
1. centrosomes and centrioles
2. cilia and flagella – include basal body
3. dynein walking
ii. microfilaments
1. actin
2. myosin
3. pseudopodia
4. cytoplasmic streaming
iii. intermediate filaments
iv. Proteoglycans
v. Fibronectin
vi. Integrins
k. What are intercellular junctions and why are they important?
Contrast plasmodesmata, tight junctions, desmosomes, and gap junctions.