Question 1

Why do prokaryotes reproduce more rapidly than single-celled eukaryotes?

Accepted Answer

Prokaryotes have much less DNA than eukaryotes, which means they have simpler cellular processes and can reproduce more rapidly.

Question 2

Which of these comparisons is correct?

Accepted Answer

D

Question 3

Individuals who participate in research as experimental subjects are

Accepted Answer

Individuals who participate in research as experimental subjects are often referred to as citizen scientists, as they contribute to scientific research without being professional scientists themselves.

Question 4

Prokaryotes are capable of reproducing more rapidly than eukaryotes because prokaryotes

Accepted Answer

The answer of Prokaryotes are capable of reproducing more rapidly...

Question 5

Which of the following pairs of domains are MOST closely related?

Accepted Answer

Archaea and Eukarya are more closely related to each other than either is to Bacteria, based on genetic evidence and the structure of cellular machinery.

Question 6

The generation time for a prokaryote is 30 minutes.If one cell is present on a petri dish,how many cells will be present after three hours?

Accepted Answer

In three hours, there are 6 intervals of 30 minutes. Therefore, the number of cells will double every 30 minutes.

At t=0 minutes: 1 cell 
At t=30 minutes: 2 cells 
At t=60 minutes: 4 cells 
At t=90 minutes: 8 cells 
At t=120 minutes: 16 cells 
At t=150 minutes: 32 cells 
At t=180 minutes: 64 cells

Therefore, after three hours, there will be 64 cells present on the petri dish.

Question 7

Escherichia coli,a bacterium that normally lives in the gut of humans,will have the shortest generation time when it is found

Accepted Answer

The generation time of a bacterium is affected by external factors such as temperature. The optimal temperature for Escherichia coli, which is a mesophilic bacteria, is around 37°C, which is close to human body temperature. Therefore, the bacteria will have the shortest generation time when it is found in an incubator set close to human body temperature.

Question 8

Which of the following groups of characteristics defines prokaryotes?

Accepted Answer

Prokaryotes are single-celled organisms that lack membrane-enclosed organelles and a nucleus. They reproduce asexually and have a single loop of DNA. These characteristics are present in option C. Options A and D describe eukaryotes, while option B is not entirely accurate since prokaryotes do not have sexual reproduction.

Question 9

Professional scientists benefit from citizen science because citizens

Accepted Answer

Citizens can help professional scientists collect samples by providing more eyes, ears, and hands to help collect data. This can improve the quality and quantity of data obtained, leading to better scientific results.

Question 10

Citizens use an app to document the location of ash trees in their community.These citizen scientists are participating

Accepted Answer

The citizens are collecting data by documenting the location of ash trees in their community. Therefore, they are participating in data collection.

Question 11

Bacteria and archaea are both classified as

Accepted Answer

Bacteria and archaea are both prokaryotes, meaning they do not have a membrane-bound nucleus or other organelles. Eukaryotes, protists, and fungi all have membrane-bound nuclei and are not classified as prokaryotes.

Question 12

If a professional scientist is trying to build an extensive database of bacterial swabs from humans in all parts of the world,what is the most cost-effective way to increase the number of samples collected in a one-year time period?

Accepted Answer

Training citizens to collect samples from the public is likely the most cost-effective way to increase the number of samples collected in a one-year time period. This approach would allow for a larger number of people to collect samples from various locations without the need to hire additional researchers or pay for travel expenses. Additionally, citizens are likely to be more familiar with the local area, which could lead to better sample collection.

Question 13

Citizen science projects contribute to scientific research by the public

Accepted Answer

Citizen science projects involve members of the public in the collection of data for scientific research. Participants may collect data through observations, measurements, or recordings, and then contribute their findings to professional research efforts. While citizen scientists may collectively form hypotheses or help to design experiments, their primary contribution is typically in the collection of data. Peer-reviewing professional research is generally reserved for trained scientists and experts in a particular field.

Question 14

Many bacteria have a shorter generation time at warmer temperatures.Why do food safety guidelines recommend rapidly cooling leftover foods and maintaining them at refrigerator temperatures?

Accepted Answer

Many bacteria reach disease-causing levels rapidly when food is warm, so it is important to cool it quickly and maintain it at refrigerator temperatures to slow down bacterial growth and prevent foodborne illnesses. The fact that bacteria have a shorter generation time at warmer temperatures is precisely why it is important to cool food rapidly.

Question 15

A prokaryotic cell and a eukaryotic cell are placed in an environment ideal for growth of both cells.After 24 hours it is observed that the prokaryote cell population is significantly higher than the eukaryote cell population.This has occurred because prokaryotes

Accepted Answer

Prokaryotic cells have a simpler structure than eukaryotic cells, which allows them to reproduce more rapidly. This gives them a competitive advantage in certain environments, including those that are ideal for both prokaryotes and eukaryotes.

Question 16

Prokaryotes have an optimum temperature for growth.If a prokaryote can divide into two cells every 20 minutes when the temperature is 37ᵒC,what would happen if the temperature dropped to 35ᵒC?

Accepted Answer

The answer of Prokaryotes have an optimum temperature for growth.If...

Question 17

As shown in the figure below,a single bacterium has a generation time of 10 minutes.Approximately how much time will have passed when the population is 100 cells?

Accepted Answer

To calculate the time it takes for a population to reach a certain size, we use the following formula:

Nf = Ni x 2^n

Where:
Nf = Final population size
Ni = Initial population size
n = Number of generations

Since each generation time is 10 minutes, we can use the following formula to calculate the number of generations:

n = log2 (Nf/Ni)

Plugging in the values, we get:

n = log2 (100/1)
n = 6.64

Since we can't have a fraction of a generation, we round up to 7 generations. So the total time it takes for the population to reach 100 cells is:

Total Time = 7 x Generation Time
Total Time = 7 x 10
Total Time = 70 minutes

Therefore, the best choice is C, 70 minutes.

Question 18

An experiment is performed to see if an antiseptic will change the skin microbiome.Skin swabs are used before an antiseptic is applied,after the antiseptic is applied,and on the same area 48 hours later.It is observed that the antiseptic drastically reduced the numbers of Staphyloccocus and other bacteria.After 48 hours Staphylococcus reappears as the most common species.What can be inferred from these results?

Accepted Answer

The reappearance of Staphylococcus as the most common species after 48 hours indicates that it has a short generation time, allowing it to quickly repopulate the area after being temporarily reduced by the antiseptic. The other answer choices are not supported by the given information.

Question 19

As a group,prokaryotes

Accepted Answer

Prokaryotes are single-celled organisms that lack a nucleus. They are distinct from eukaryotes, which have a true nucleus and other membrane-bound organelles. Prokaryotes also lack membrane-bound organelles, such as mitochondria or chloroplasts, which are found in eukaryotic cells. However, some prokaryotes do possess pili, which are hair-like structures used for attachment or movement. Prokaryotes are found in a wide range of environments and can obtain energy from a variety of sources, including inorganic chemicals.

Question 20

A single-celled organism has linear DNA enclosed within a nucleus.This organism must be a(n)

Accepted Answer

Eukaryotes are characterized by having a true nucleus, which contains linear DNA, and are typically single-celled or multicellular organisms. Bacteria and archaea are both prokaryotes, which lack a nucleus and their DNA is typically circular and not enclosed within a nuclear envelope. Therefore, the best choice is A.

Quiz 15: Bacteria and Archaea