Question
Explain Gross primary productivity and Net primary productivity.
✓
Answer
→ Primary productivity :
→ Primary production is defined as the amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis.
→ Primary productivity depends on the plant species inhabiting a particular area.
→ It also depends on a variety of environmental factors, availability of nutrients and photosynthetic capacity of plants.
→ Therefore, it varies in different types of ecosystems. The annual net primary productivity of the whole biosphere is approximately 170 billion tons (dry weight) of organic matter.
→ Of this, despite occupying about 70 percent of the surface, the productivity of the oceans are only 55 billion tons.
→ Primary production is defined as the amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis.
→ Primary productivity depends on the plant species inhabiting a particular area.
→ It also depends on a variety of environmental factors, availability of nutrients and photosynthetic capacity of plants.
→ Therefore, it varies in different types of ecosystems. The annual net primary productivity of the whole biosphere is approximately 170 billion tons (dry weight) of organic matter.
→ Of this, despite occupying about 70 percent of the surface, the productivity of the oceans are only 55 billion tons.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Since the origin of life on earth, there were five episodes of mass extinction of species.
- How is the 'Sixth Extinction', presently in progress, different from the previous episodes?
- Who is mainly responsible for the 'Sixth Extinction?
- List any four points that can help to overcome this disaster.
State one advantage and one disadvantage of cleistogamy.
For which variety of Indian rice, the patent was filed by a USA Company?
Where do the following events occur in the life-cycle of Plasmodium?
- Gametocyte development.
- Sexual reproduction.
- Asexual reproduction.
A relevant portion of B-chain of haemoglobin of a normal human is given below:
The codon for the sixth amino acid is GAG. The sixth codon GAG mutates to GAA as a result of mutation 'A' and to GUG as a result of mutation 'B'. Haemoglobin structure did not change as a result of mutation 'A', whereas haemoglobin structure changed because of mutation 'B', leading to sickle-shaped RBCs. Explain giving reasons how could mutation 'B' change the haemoglobin structure or bring down mutation and not mutation 'A'.
The codon for the sixth amino acid is GAG. The sixth codon GAG mutates to GAA as a result of mutation 'A' and to GUG as a result of mutation 'B'. Haemoglobin structure did not change as a result of mutation 'A', whereas haemoglobin structure changed because of mutation 'B', leading to sickle-shaped RBCs. Explain giving reasons how could mutation 'B' change the haemoglobin structure or bring down mutation and not mutation 'A'.
What is RCH programme ?
Mention the kind of biodiversity of more than a thousand varieties of mangoes in India represent. How is it possible?
Despite the Green Revolution, is there any alternative way by which maximum production can be achieved with minimum use of fertilizers and chemicals?
Explain giving three reasons why tropics show, greatest level of species diversity.
Who proposed the theory of origin of life? What were the conditions prevailing about 3.6 billion years ago, to create life on primitive earth?