Download Textbook Question for Viruses and Bacteria Page

Textbook Question for Viruses and Bacteria
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1. Describe the structure of a virus. Why are viruses considered to be non-living?
- Viruses are considered non-living things as they have no cellular structure: no cytoplasm, organelles, or
cell membranes which make it impossible for them to perform any life processes on their own. The
structure of a virus consists of strands of DNA or RNA surrounded by a capsid (protective protein coat).
2. Why must a virus enter a host cell in order to reproduce itself?
- Viruses are dependent on eukaryotic and prokaryotic cells to reproduce the viral DNA/RNA and to make
protein coats for protection as they lack organelles to reproduce on their own.
5. A doctor tells a patient that an antibiotic will not help cure a cold sore. Explain the doctor’s reasoning.
- The doctor will not prescribe an antibiotic as a virus is not a living thing, and antibiotics will only work on
living things. As viruses have a different structure (no organelles and a protective capsid) and reproduce
differently than living things (use eukaryotic and prokaryotic cells), then antibiotics will not work against
them.
7. Explain how viruses might be used to copy the gene for producing human insulin.
- Viruses can be used to copy various genes by splicing other DNA into the viral DNA. If the goal was to
produce human insulin, the insulin producing gene would need to be spliced into the viral DNA. As the
virus reproduced it would also create more human insulin creating structures.
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1. Which of the following are true of prokaryotes?
(a) They include both archaea and bacteria.
- This is true as prokaryotes are bacteria which also include the archaea.
(b) They lack a nucleus.
- Instead of a nucleus bacterium have a concentration of genetic material.
(c) They are only found in extremely hot environments.
- The archaea bacteria are found in extreme environments (such as extremely hot environments), but
bacteria/eubacteria can be found anywhere.
(d) They are all parasitic.
- Not all prokaryotes are parasitic. Bacteria are also decomposers and converters of materials.
2. How are members of Kingdom Bacteria classified?
- Members of Kingdom bacteria are classified based on their shape: Cocci (round), bacilli (rod-shaped), and
spirilli (spiral shaped).
5. Describe two processes that kill harmful bacteria. Write a paragraph explaining how one of the processes
works.
- One process used to kill harmful bacteria would be to use an autoclave (container that contains
pressurized steam). A second way to kill these bacteria would be using antibiotics.
- Using antibiotics stops bacterial growth by interfering with the growth and reproductive functions of the
bacteria. When antibiotics are present, bacteria are unable to repair cell walls, membranes, and produce
more genetic material.
6. How do antibiotics combat bacteria?
- Using antibiotics stops bacterial growth by interfering with the growth and reproductive functions of the
bacteria. When antibiotics are present, bacteria are unable to repair cell walls, membranes, and produce
more genetic material.
7. The images at the top right are illustrations of a bacterial cell dividing into two cells. In your notebook, redraw
the figures in the proper sequence and explain what is happening at each step.
3
.
-
1.
2.
3.
4.
5.
Copies chromosome
Cell elongates
Septum begins to form
Septum completes
Cells separates
2
.
5
.
1
.
4
.