Question

Desulfovibrio is bacterium that breaks down organic matter which it must have and uses sulphate not oxygen as an electron acceptor. As a result, it produces hydrogen sulphide, accounting for the 'rotten egg'smell of swamp muck. Oxygen is a deadly poision toDesulfovibrio. We would call Desulfovibrio a(n):

(a) facultatively anaerobic chemoautotroph
(b) obligately anaerobic chemoheterotroph.
(c) facultatively aerobic chemoheterotroph.
(d) obligately anaerobic chemoautotroph.

Explain your answer.​

Answer 1

♣ Qᴜᴇꜱᴛɪᴏɴ :

Desulfovibrio is bacterium that breaks down organic matter which it must have and uses sulphate not oxygen as an electron acceptor. As a result, it produces hydrogen sulphide, accounting for the 'rotten egg'smell of swamp muck. Oxygen is a deadly poision toDesulfovibrio. We would call Desulfovibrio a(n):

(a) facultatively anaerobic chemoautotroph

(b) obligately anaerobic chemoheterotroph.

(c) facultatively aerobic chemoheterotroph.

(d) obligately anaerobic chemoautotroph.

Explain your answer.​

♣ ᴀɴꜱᴡᴇʀ :

According to question , bacterium breaks down organ matter that uses sulphur.

So we can say it performs Anaerobic respiration.

We can say above statement is true as it is not using oxygen,

And also we can mention that this organism is completely oblegate.

This performs Chemoheterotrophism

Lets see from options now :

a. facultatively anaerobic chemoautotroph

Facultatively anaerobic chemoautotroph means incomplet anaerobic which can use oxygen in emergency situations and breakdown and this will be not our answer as oxygen is not deadly here.

b.  obligately anaerobic chemoheterotroph    (Required answer)

This statement satisfies our conditions and hence true

c. facultatively aerobic chemoheterotroph.

This will be false as it is a aerobic organism. Our answer needs to be a complete anaerobic organism

d. obligately anaerobic chemoautotroph.

Autotrophs makes their own food which is not the case in the bacteria so this statement will also be false.

Note :

• Obligate anaerobes are poisoned by oxygen. Chemoheterotrophs must consume organic molecules for both energy and carbon.

Our answer will be : Option (b) obligately anaerobic

chemoheterotroph.

Answer 2

Answer:

option B is the correct answer

Explanation:

hope it helps you