Browse by Stream
-
Engineering and Architecture
Exams
Colleges
Predictors
Resources
-
Computer Application and IT
Quick Links
Colleges
-
Pharmacy
Colleges
Resources
-
Hospitality and Tourism
Colleges
Resources
Diploma Colleges
-
Competition
Other Exams
Resources
-
School
Exams
Top Schools
Products & Resources
-
Study Abroad
Top Countries
Resources
-
Arts, Commerce & Sciences
Colleges
Upcoming Events
Resources
-
Management and Business Administration
Exams
Colleges & Courses
Predictors
-
Learn
Law Preparation
MBA Preparation
Engineering Preparation
Medical Preparation
-
Online Courses and Certifications
Top Streams
Specializations
- Digital Marketing Certification Courses
- Cyber Security Certification Courses
- Artificial Intelligence Certification Courses
- Business Analytics Certification Courses
- Data Science Certification Courses
- Cloud Computing Certification Courses
- Machine Learning Certification Courses
- View All Certification Courses
Resources
-
Medicine and Allied Sciences
Colleges
Predictors
Resources
-
Law
Resources
Colleges
-
Animation and Design
Exams
Predictors & Articles
Colleges
Resources
-
Media, Mass Communication and Journalism
Colleges
Resources
-
Finance & Accounts
Top Courses & Careers
Colleges
Get Answers to all your Questions
- #National Eligilibility Cum Entrance Test
- #Class 11
- #Plant Physiology
- #National Eligibility Cum Entrance Test
- #Medical
- #Biology
Which of the following form of nitrogen is directly absorbed by the plants?
Option: 1
Dinitrogen
Option: 2
Ammonia
Option: 3
Nitrate
Option: 4
Both a and b
Answers (1)
1. Ammonification
- Ammonification is a process in which the organic nitrogen of plants and animals after their death is converted to ammonium ions (NH4) by the action of saprotrophic fungi and bacteria.
- The saprotrophs use ammonia (NH3) to synthesize their own proteins and other nitrogen-containing organic compounds.
2. Nitrification:
- Ammonium ions added to the soil by ammonification, are soon oxidized by a process known as nitrification.
- It takes place in two stages.
- In the first stage, ammonium (NH4+) is converted to nitrite (NO2-).
- This reaction involves the addition of oxygen to ammonia, giving rise to hydroxylamine (NH2OH), which is further oxidized to nitrite.
- This reaction is completed by bacteria such as
- The second stage of nitrification involves the oxidation of nitrite (NO2) to nitrate (NO3) by bacteria like Nitrobacter, Nitrospira and Nitrococcus.
- The reaction proceeds by the addition of water followed by the removal of hydrogen.
TIP:
- Nitrate (NO3–) formed in the process of nitrification is used by most plants as a mineral metabolite and may be converted by them into amino groups and other nitrogen-containing compounds.
- Nitrates are also added to the soil through rock dissolution and a combination of atmospheric nitrogen with oxygen by lightning (nitrates so formed reach the soil by rain).
- However, many plants also absorb ammonia from the soil.
3. Denitrification:
- It is a process in which the nitrate ion (NO3) is reduced to nitrogen dioxide (NO2), di-nitrogen oxide (N2O), nitrogen monoxide (NO) or nitrogen (N2) by certain soil bacteria like Pseudomonas denitrificans.
- Thus, nitrogen is liberated into the atmosphere.
- Plants also lose small amounts of nitrogen to the atmosphere as gaseous ammonia, N2O, NO2 and NO especially when well fertilized with nitrogen
Hence, the correct answer is option d.
View full answer
NEET 2024 Most scoring concepts
- Just Study 32% of the NEET syllabus and Score up to 100% marks
