Tag: bio-geo chemical cycles in nature

Quizzes (5) Questions (95)

Questions Related to bio-geo chemical cycles in nature

Multiple choice zoology bio-geo chemical cycles in nature nitrogen cycle biogeochemical cycles - gaseous nutrient cycles

Which gene cluster is responsible for nitrogen fixation in bacteria?

  1. Nod, Nif, Nfx

  2. Nod, Nif, Fix

  3. Nod, Ndf, Nfx

  4. Ndx, Nif, Fix

  5. Ndx, Nif, nix
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Nitrogen fixation is a process by which nitrogen present in the atmosphere is converted into ammonia. It is essential to life because fixed inorganic nitrogen compounds are required for the biosynthesis of all nitrogen-containing compounds. This process is done with the help of nitrogen-fixing bacteria that have Nod, Nif and Fix gene clusters responsible for nitrogen fixation.
So the correct answer is 'Nod, Nif, Fix'.
Multiple choice zoology bio-geo chemical cycles in nature nitrogen cycle biogeochemical cycles - gaseous nutrient cycles

Match the columns and choose the correct option.

I II
(a) Free-living aerobic nitrogen fixers 1. Anabaena and Nostoc
(b) Anaerobic nitrogen fixers 2. Pseudomonas and Thiobacillus
(c) Nitrogen-fixing cyanobacteria 3. Nitrosomonas and Nitrosococcus
(d) Denitrifying bacteria 4. Azotobacter and Beijerinckia
(e) Nitrifying bacteria 5. Rhodospirillum

  1. a - 4, b - 5, c - 1, d - 2, e - 3 

  2. a - 5, b - 4, c - 1, d - 3, e - 2

  3. a - 4, b - 5, c - 2, d - 3, e - 1

  4. a - 4, b - 3, c - 1, d - 2, e - 5

  5. a - 4, b - 5, c - 3, d - 2, e - 1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
a) Free-living aerobic nitrogen fixers - Azotobacter and Beijernikia
b) Anaerobic nitrogen fixers - Rhodospirillum
c) Nitrogen-fixing cyanobacteria - Anabaena and Nostoc
d) Denitrifying bacteria - Pseudomonas and Thiobacillus
e) Nitrifying bacteria - Nitrosomonas and Nitosococcus
So the correct answer is 'a-4, b-5, c-1, d-2, e-3'
Multiple choice zoology bio-geo chemical cycles in nature nitrogen cycle biogeochemical cycles - gaseous nutrient cycles

Which one helps in absorption of phosphorus from soil by plants?

  1. Frankia

  2. Anabaena

  3. Glomus

  4. Rhizobium
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Frankia, Anabaena and Rhizobium are nitrogen-fixing bacteria that absorbs nitrogen from the soil. Glomus is a myccorhizal fungi. The fungal symbiont in these associations absorbs phosphorus from soil and passes it to the plant.
Thus, the correct answer is option (C). 

Multiple choice zoology bio-geo chemical cycles in nature nitrogen cycle biogeochemical cycles - gaseous nutrient cycles

Which of the following is the function of nitrifying bacteria?

  1. Oxidise $NH _3$ to $NO^- _3$

  2. Oxidise $NH _3$ to $NH^+ _4$

  3. Convert $NO^- _3$ to $NH _3$

  4. Convert $NO^- _3$ to $N _2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Nitrifying bacteria is an aerobic bacteria that use inorganic chemicals as an energy source. They are important in the nitrogen cycle as converters of soil ammonia to nitrates by the process of oxidation.
So the correct answer is 'oxidise NH$ _3$ to NO$ _3$-'.