Exploring Creation with Biology second edition Module 2 study guide

1. A. Pathogen
An organism that causes disease

B. Saprophyte
An organism that feeds on dead matter

C. Parasite
An organism that feeds on a living host

D. Aerobic organism
An organism that requires oxygen

E. Anaerobic organism
An organism that does not require oxygen

F. Steady state
A state in which members of a population die as quickly as new members are born

G. Exponential growth
Population growth that is unhindered because of the abundance of resources for an ever-increasing population

H. Logistic growth
Population growth that is controlled by limited resources

I. Conjugation
A temporary union of two organisms for the purpose of DNA transfer

J. Plasmid
A small, circular section of extra DNA that confers one or more traits to a bacteria and can be reproduced separately from the main bacterial genetic code

K. Transformation
The transfer of a DNA segment from a nonfunctional donor cell to that of a functional recipient cell

L. Transduction
The process in which infection by a virus results in DNA being transferred from one bacterium to another

M. Endospore
The DNA and other essential parts of a bacterium coated with several hard layers

N. Strains
Organisms from the same species that have markedly different traits

2. Label all of the indicated structures on the bacterium below
A. Plasma membrane
B. Flagellum
C. Capsule
D. DNA
E. Cytoplasm
F. Cell wall
G. Fimbria
H. Ribosome

3. Describe the functions of each components in problem 2
A. Plasma membrane: To negotiate what materials pass into and out of the cell
B. Flagellum: To move the bacterium from place to place
C. Capsule: To adhere to surfaces as well as to ward off infection-fighting agents
D. DNA: To store the information needed to make an organism a living thing
E. Cytoplasm: To hold the DNA and ribosomes in place
F. Cell wall: To keep the interior of the cell together and to hold the cell’s shape
G. Fimbria: To grasp onto surfaces or another bacterium during conjugation
H. Ribosome: To make proteins

4. What is the most popular means by which bacteria obtain food?
Most bacteria are heterotrophic decomposers

5. If a bacterium is parasitic, is it heterotrophic or autotrophic?
If a bacterium is parasitic it will be heterotrophic

6. List the basic steps in asexual reproduction among bacteria.
The DNA loop attaches to a point on the plasma membrane
Then the DNA is copied and the copy is attached to a point on the plasma membrane near the original
The cell wall elongates
And the new cell wall and plasma membrane material grow, closing the two loops off from each other
Eventually, the cell wall and plasma membrane pinch down forming two cells

7. A sample of food is dehydrated, which kills all of the bacteria. However, in a few days, bacteria-free water is added to the food in a bacteria-free environment. Nevertheless, microscope investigations indicate that bacteria are in the food. How did the bacteria get there?
The bacteria that are there were in the food as endospores

8. What kind of growth does a population of bacteria experience when just a few of them are placed in an environment rich with resources?
The bacteria will experience exponential growth

9. A population of bacteria experiences logistic growth. What can you say about the resources of their environment?
The bacteria’s resources are limited but do not run out

10. Even though genetic recombination among bacteria does not result in offspring it can significantly affect the growth of the population. Why?
Genetic recombination can pass a trait from one bacterium to another. If that trait allows the recipient to survive conditions that it otherwise wouldn’t, the population is affected, because the recipient continues to live and reproduce asexually

11. What are the technical names of the three common bacterial shapes?
Coccus – Spherical
Bacillus – Rod-shaped
Spirillum – Helical

12. A bacterium is heterotrophic and Gram-negative. To what phylum and class does it belong?
It belongs to phylum Gracilicutes and class Scotobacteria

13. A spirillum bacterium is Gram-positive. To what phylum and class does it belong?
It belongs to phylum Firmicutes and class Thallobacteria

14. A bacterium has no cell wall. To what phylum and class does it belong?
It belongs to phylum Tenericutes and class Mollicutes

15. A bacterium lives in boiling-hot water. To what phylum and class does it most likely belong?
It most likely belongs to phylum Mendosicutes and class Archaebacteria

16. In the six-kingdom classification system, what replaces kingdom Monera?
Kingdom Monera is split into kingdom Archaebacteria and kingdom Eubacteria

17. What conditions are ideal for most bacteria to grow and reproduce?
Moisture
Moderate temperatures
Nutrition
Darkness
The proper amount of oxygen

18. What methods exist for reducing the chance of bacterial contamination of food?
A. Heat the food so that most bacteria die and then seal it away from fresh air
B. Dehydrate the food
C. Freeze the food
D. Pasteurize the food
E. Keep it in the refrigerator