• Home
  • Textbooks
  • Biology Now
  • Bacteria and Archaea

Biology Now

Anne Houtman; Megan Scudellari; Cindy Malone

Chapter 15

Bacteria and Archaea - all with Video Answers

Educators

Chapter Questions

01:33

Problem 1

Prokaryotes include
(a) archaeans.
(b) bacteria.
(c) fungi.
(d) both $\underline{a}$ and $b$
(e) both $b$ and $c$

Sana Riaz
Sana Riaz
Numerade Educator
01:32

Problem 2

Some prokaryotes can
(a) break down chemicals for energy.
(b) use sunlight for energy.
(c) create their own energy.
(d) harvest energy from other organisms.
(e) all of the above

Sana Riaz
Sana Riaz
Numerade Educator
02:20

Problem 3

Prokaryotes are extremely abundant because
(a) they can survive in a narrow range of environments.
(b) they have a single loop of DNA.
(c) they reproduce very rapidly.
(d) they are able to form biofilms.
(e) all of the above

Sana Riaz
Sana Riaz
Numerade Educator
02:06

Problem 4

Quorum sensing
(a) is the transfer of plasmid DNA from one bacterium to another.
(b) enables bacteria to form biofilms.
(c) is the formation of thick-walled dormant structures, called spores, under conditions unfavorable for growth.
(d) enables bacteria to switch from cellular respiration to fermentation when they sense that oxygen levels are low.

Sana Riaz
Sana Riaz
Numerade Educator
03:40

Problem 5

Select the correct terms:
Of the two types of prokaryotes, (Archaea / Bacteria] are more closely related to eukaryotes. The domain (Archaea / Bacteria) contains some species that are pathogens. (Prokaryotes Eukaryotes) have smaller, less complex cells and are able to reproduce at a more rapid rate. Some (prokaryotes / eukaryotes) are multicellular.

Sana Riaz
Sana Riaz
Numerade Educator
01:14

Problem 6

Which of the following can prokaryotes not do?
(a) communicate with each other about environmental conditions
(b) reproduce sexually
[c] live in extreme environments, including high salt, high
temperature, and high atmospheric pressure
(d) share DNA with other prokaryotes
[e] double in population size two or more times an hour

Sana Riaz
Sana Riaz
Numerade Educator
01:11

Problem 7

Which of the following descriptions is true only of prokaryotes?
(a) They reproduce through binary fission.
(b) Theil genetic material is DNA.
(c) They are unicellular.
(d) They contain organelles within the cell.
[e) none of the above

Sana Riaz
Sana Riaz
Numerade Educator
04:21

Problem 8

8) Place the following steps of the belly button research described in this chapter in the correct order by numbering them from 1 to 5 .
____a. An observation was made that belly button bacteria seemed to differ across individuals.
____b. The DNA was sequenced.
____C. DNA was isolated from the samples.
____d. Volunteers had their navels swabbed to collect bacterial
samples.
____e. The bacterial samples were grown in petri dishes.

Sana Riaz
Sana Riaz
Numerade Educator
02:46

Problem 9

Which of the following is citizen science?
(a) reporting when the first hummingbirds arrive at your feeders in the spring
(b) completing a Facebook quiz on your horoscope
[c) filling out your medical history at the doctor's office
[d) all of the above
(e) none of the above

Sana Riaz
Sana Riaz
Numerade Educator
05:30

Problem 10

There are more genera of bacteria and archaeans in the world than of eukaryotes, and more individuals. However, the total mass of prokaryotes is thought to be approximately equal to that of eukaryotes. How can this be?

Sana Riaz
Sana Riaz
Numerade Educator
02:46

Problem 11

Why are prokaryotes able to replicate so much more quickly than eukaryotes? (Hint: What cellular components must be copied before a cell splits in two?] Why is this difference in replication rate an important part of our vulnerability to bacterial pathogens?

Sana Riaz
Sana Riaz
Numerade Educator
07:30

Problem 12

Doing science The research discussed in this chapter would not have been possible without the many citizen scientists who shared samples of their belly button microbes with the research
team. Choose a citizen science project: Perform an Internet search on the term "citizen science project," or find regularly updated lists of projects at Scitable (ht tp://www.scitable.com] and Your Wild Life (http://www.yourwildlife.org]. Write a one-paragraph summary of the goals of the project you have chosen. Would you participate in this project? Why or why not? Describe a citizen science project that you would want to contribute to.

Sana Riaz
Sana Riaz
Numerade Educator
07:05

Problem 13

The table here is based on the published results of the study discussed in the chapter. It shows the number of bacterial phylotypes (kinds of bacteria) that were found on a particular percentage of people.
a. How many bacterial phylotypes were found on only 10 percent or fewer of the people sampled? How many were found on more than 90 percent of people?
b. How many phylotypes were found on more than half of the people sampled?
C. Describe in one or two sentences the frequency of phylotypes found in the study. Were most phylotypes rare or common?
$$\begin{array}{ll}\text { Phylotypes } & \begin{array}{l}\text { Percentage of Human } \\
\text { Samples Where Found }
\end{array} \\\hline 2,188 & 1-10 \\97 & 11-20 \\31 & 21-30 \\
12 & 31-40 \\17 & 41-50 \\11 & 51-60 \\
4 & 61-70 \\2 & 71-80 \\2 & 81-90 \\
4 & 91-100\end{array}$$

Sana Riaz
Sana Riaz
Numerade Educator