Question 1

Which of the following best describes the primary function of the bioluminescent glow produced by the light organ of the bobtail squid?

Accepted Answer

It camouflages the squid against the sandy ocean floor by matching the downwelling light.

Question 2

The relationship between the bobtail squid and Vibrio fischeri is an example of mutualism. Which statement best explains why this is considered mutualism?

Accepted Answer

Both the squid and the bacteria benefit: the squid gains camouflage, and the bacteria gain nutrients and protection.

Question 3

If no Vibrio fischeri are present in the environment, what is most likely to happen during the development of the bobtail squid?

Accepted Answer

The squid's light organ does not develop completely and does not glow.

Question 4

Which of the following is a structural similarity between the squid's light organ and the eye?

Accepted Answer

Both can detect and respond to light.

Question 5

Why is it important for the bobtail squid to be able to detect light as well as emit it?

Accepted Answer

Detecting light allows the squid to adjust its bioluminescence for effective camouflage.

Question 6

Which of the following best describes a communication method between the squid and Vibrio fischeri bacteria?

Accepted Answer

The squid releases chemical signals that attract Vibrio fischeri to colonize its light organ.

Question 7

During the day, the bobtail squid ejects about 95% of the bacteria from its light organ. What is the most likely reason for this behavior?

Accepted Answer

To prevent overpopulation of bacteria and maintain a healthy balance within the light organ.

Question 8

Once the light organ is colonized, the squid no longer takes in Vibrio fischeri from the environment. How is a sufficiently large population of bacteria maintained in the light organ?

Accepted Answer

The bacteria reproduce rapidly within the protected environment of the light organ.

Question 9

Which equation best represents the population growth of Vibrio fischeri within the squid's light organ, assuming unlimited resources?

Accepted Answer

$$N_t = N_0$ e$$^{rt}$$

Question 10

If the squid's light organ ejects 95% of its bacteria each morning, what percentage of the original bacteria population remains?

Accepted Answer

$$5\%$$

Question 11

Which of the following is NOT a benefit that Vibrio fischeri receives from living in the squid's light organ?

Accepted Answer

Ability to photosynthesize using sunlight.

Question 12

Which process allows the squid to regulate the population of Vibrio fischeri in its light organ?

Accepted Answer

Daily expulsion of most bacteria from the light organ.

Question 13

If the squid did not expel bacteria from its light organ, what would most likely happen?

Accepted Answer

The bacteria population would grow uncontrollably, potentially harming the squid.

Question 14

Which of the following best describes counterillumination in the bobtail squid?

Accepted Answer

The squid matches the light from above to avoid casting a shadow and being detected by predators.

Question 15

Which of the following is a real-world application of studying the squid-Vibrio fischeri symbiosis?

Accepted Answer

Understanding cellular communication between animals and bacteria.

Question 16

Which of the following is a plausible consequence if the squid's light organ failed to develop?

Accepted Answer

The squid would be more visible to predators and have reduced survival rates.

Question 17

Which of the following best explains why the squid ejects most of its bacteria during the day?

Accepted Answer

To prevent excessive bacterial growth and maintain optimal light production at night.

Question 18

Which of the following is an example of communication between the squid and its symbiotic bacteria?

Accepted Answer

The squid provides nutrients that signal the bacteria to produce light.

Question 19

Which of the following equations would you use to calculate the percentage of bacteria remaining after the squid ejects 95% of them?

Accepted Answer

$$P_{remaining} = P_{initial} 	imes 0.05$$

Question 20

Which of the following is a critical insight gained from the study of the bobtail squid and Vibrio fischeri symbiosis?

Accepted Answer

Symbiotic relationships can drive the development and function of animal organs.

Symbiosis and Bioluminescence: The Bobtail Squid and Vibrio fischeri

Study Guide - Practice Questions

Study Guide - Flashcards