Chapter 18, Problem 8A

Summary Introduction

Introduction:

Bacteria and the archaea are the domain of the prokaryotic organisms. They are microscopic and lack true membrane bound nucleus and other organelles.

Answer to Problem 8A

Option (C).

Explanation of Solution

Explanation for correct answer:

Option (C). The E.coli is a bacteria that can survive in human body, even these bacteria are already present in gut, but if they are transferred to the blood stream or any other part of body, they may cause major infections. So, they will be harmful to ingest. Hence, it is the correct answer.

Explanation for incorrect answer:

Option (A) thermoacidophile bacteria. The thermoacidophile belong to archaea. They can survive in high temperature and low pH, which is highly acidic condition. As the body temperature is not very high, it would not survive in the body for long and cannot harm. Hence, it is an incorrect answer.

Option (B) halophilic bacteria. Halophiles are salt loving and can survive in high salt conditions. In the body, the salt concertation is not very high, so, ultimately, this organism cannot survive for long. Hence, it is an incorrect answer.

Option (D) bacteriophage. The bacteriophage is a virus that infects the bacteria, the virus is not able to humans directly. Hence, it is an incorrect answer.