Module 2 (vocabulary is on Biology ipad app)

Question 1

See page 65, The answer will be for both questions #2 & #3.

Answer 1

a. plasma membrane: To negotiate what materials pass into and out of the cell
b. flagellum: to move the bacteria 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 & 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

Question 2

What is the most popular means by which bacteria obtain food?

Answer 2

heterotrophic decomposers

Question 3

If a bacterium is parasitic, is it heterotrophic or autotrophic?

Answer 3

heterotrophic

Question 4

List the basic steps in asexual reproduction among bacteria.

Answer 4

At first, the DNA loop attaches to a point on the plasma membrane. After that, the DNA copied, and the copy is attached to a point on the plasma membrane near the original. Then, the cell wall elongates, which separates the two loops of DNA. Once they are sufficiently separated, 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 where there was only one before.

Question 5

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, microscopic investigations indicate that bacteria are in the food. How did the bacteria get there?

Answer 5

The bacteria that are there were in the food as endospores.

Question 6

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

Answer 6

exponential growth

Question 7

A population of bacteria experiences logistic growth. What can you say about the resources of their environment?

Answer 7

the resources are limited but do not run out

Question 8

Even though genetic recombination among bacteria does not result in offspring, it can significantly affect the growth of the population. Why?

Answer 8

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.

Question 9

What are the technical names of the three common bacterial shapes?

Answer 9

Coccus - Spherical
Bacillus - Rod-shaped
Spirillum - Helical

Question 10

A bacterium is heterotrophic and Gram-negative. To what phylum and class does it belong?

Answer 10

phylum Gracilicutes
class Scotobacteria

Question 11

A spirillum bacterium is Gram-positive. To what phylum and class does it belong?

Answer 11

phylum Firmicutes
class Thallobacteria

Question 12

A bacterium has no cell wall. To what phylum and class does it belong?

Answer 12

phylum Tenericutes
class Mollicutes

Question 13

A bacterium lives in boiling hot-water. To what phylum and class does it most likely belong?

Answer 13

phylum Mendosicutes
class Archaebacteria

Question 14

In the six-kingdom classification system, what replaces kingdom Monera?

Answer 14

kingdom Archaebacteria

kingdom Eubacteria

Question 15

What conditions are ideal for most bacteria to grow and reproduce?

Answer 15

Moisture, moderate temperatures, nutrition, darkness, and the proper amount of oxygen

Question 16

What methods exist for reducing the chance of bacterial contamination of food?

Answer 16

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.