IGCSE Biology Paper-4: Specimen Questions with Answers 67 - 69 of 279

Glide to success with Doorsteptutor material for Bank-PO : get questions, notes, tests, video lectures and more- for all subjects of Bank-PO.

Question 67

Edit

Describe in Detail

Essay▾

What is the microbial ecology of the nitrogen cycle?

Explanation

The nitrogen cycle is the conversion of nitrogen into its different forms by the use of microorganisms. In nitrogen fixation, atmospheric nitrogen is fixed to be used by plants. It is done by many symbiotic bacteria (diazotrophs) . These bacteria have nitrogenase enzyme that combines with N2 gas with hydrogen to produce ammonia. Rhizobium and azotobactors are the example of it.

Here they form a mutualistic relationship with the plant, producing ammonia in exchange for carbohydrates. Sometimes bacteria or fungi convert the organic nitrogen within the remains back into ammonium (NH4 + ) , a process called ammonification and the process of conversion of ammonia to nitrate is also done by soil-living bacteria such as nitrobacterium. Nitrification process is performed by bacterial species such as pseudomonas and clostridium.

Passage

There is a flow chart is given in which different type of animals are shown

Shows Given Charts in Different Types of Animals

Question 68 (1 of 2 Based on Passage)

Edit

Write in Brief

One Liner▾

What is the difference between animal A and Animal D?

Explanation

Animal A is herbivore and animal D is not herbivore.

Question 69 (2 of 2 Based on Passage)

Edit

Write in Short

Short Answer▾

Identify them from (Guppy, Snake, Giraffe and tiger)

Explanation

Animal A- Giraffe

Animal B- Snake

Animal C-Guppy

Animal D-Tiger

Developed by: