Productivity NEET 2026: Correct Match and NPP Formula

What is the correct match in the Productivity NEET 2026 question?

Option (1) is correct in the productivity NEET 2026 match-the-following question: A-III, B-I, C-IV, D-II. This Biology question belongs to Ecology and Environment. The question bank rates it medium difficulty and gives an expected solving time of 60 seconds, not a separate exam time limit.

Pair the four ecological productivity terms with their corresponding descriptions. Keep the term labels separate from the numbered answer choices.

Terms

Descriptions

• I: Primary production remaining after respiration is deducted.
• II: New organic matter formed by consumers per unit time.
• III: Biomass produced per unit time.
• IV: Organic matter generated through photosynthesis per unit time.

Complete answer choices

How do you establish all four matches before selecting an option?

Match the identifying words in A-to-D order: biomass production rate, subtraction of respiration, photosynthesis and consumers. This definition-first method establishes every pair independently, without relying on the answer choices.

Step 1: Match Productivity with III.

Productivity means the rate of biomass production, so A matches III. The word rate matters: it describes production per unit time, not the amount of biomass present at one instant.

Step 2: Match Net primary productivity with I.

GPP means gross primary productivity, and R represents respiration losses by the primary producers. Net primary productivity is what remains after those losses are deducted: $\mathrm{N}\mathrm{P}\mathrm{P}=\mathrm{G}\mathrm{P}\mathrm{P}-R$

Therefore, B matches I. Here, R is producer respiration, not consumer respiration or an unrestricted total of all ecosystem respiration.

Step 3: Match Gross primary productivity with IV.

Gross primary productivity measures the rate of organic matter production during photosynthesis, so C matches IV. Gross identifies production before producer respiration is subtracted; net identifies the production remaining after that subtraction. Both are rates, so “per unit time” alone does not distinguish them.

Step 4: Match Secondary productivity with II.

Secondary productivity measures the formation of new organic matter by consumers per unit time, so D matches II. Consumer biomass production is distinct from photosynthetic production: the identifying word here is consumers.

Now assemble the complete result: A-III, B-I, C-IV, D-II. All four pairs agree with option (1), labelled A in the supplied question bank. That answer label A must not be confused with term A, Productivity.

Why does option (3) fail even though two matches are correct?

Option (3) interchanges the definitions assigned to A and B. It gives A-I, B-III, C-IV, D-II. C-IV and D-II are correct, but the complete mapping is wrong.

The error is treating “productivity” as shorthand for net primary productivity. That assigns the specialised respiration-subtraction definition to the general term.

NPP is also a production rate, but this one-to-one question supplies its more specific definition: gross primary productivity minus producer respiration losses. Assign that definition to B and the general biomass-production-rate definition to A.

Use the most specific definition provided, then check all four pairs. Two correct pairs are not enough.

Any scoring comparison needs a stated marking rule. If a single-choice rule awards four marks for the correct option, deducts one mark for a wrong option and gives no partial credit, option (1) earns four marks and option (3) loses one mark: $4-(-1)=5\text{marks}$

That calculation is conditional, not evidence of a marking rule supplied with this question.

What happens to NPP if producer respiration increases?

NPP decreases when GPP stays constant and producer respiration increases. This and the next two exercises are original same-chapter practice, not additional verified NEET PYQs.

Question: If GPP remains constant while producer respiration increases, does NPP increase, decrease or stay unchanged?

Answer: $\mathrm{N}\mathrm{P}\mathrm{P}=\mathrm{G}\mathrm{P}\mathrm{P}-R$

Let the increase in producer respiration be: $\Delta R>0$

Then:

NPP decreases by exactly the increase in respiration, provided the quantities use consistent units and refer to the same interval. A larger respiration loss is subtracted from an unchanged gross production rate.

How do you distinguish photosynthetic production from consumer production?

Photosynthetic production before respiration is deducted is GPP; new organic matter formed by consumers is secondary productivity. Classify the process, rather than recalling the order of the original definitions.

Original same-chapter practice: Identify these two rates:

• Total organic matter formed through photosynthesis before respiration is deducted.
• New organic matter formed as consumers build biomass.

Answer: The first is gross primary productivity. “Before respiration is deducted” separates gross production from net primary production.

The second is secondary productivity, because consumers form the new organic matter. Food consumed is not itself secondary productivity. The definition concerns new organic matter formed by consumers, not simply how much they eat.

Is one measurement of biomass enough to determine productivity?

No. A single biomass measurement gives an amount present, not a production rate. Productivity concerns biomass production per unit time, so the report needs information about production over an interval.

Original same-chapter practice: A report gives only the biomass present at one instant. Is that enough to determine productivity?

Answer: It is not. More biomass present does not, by itself, establish a higher production rate. Standing biomass tells you what is present, not how quickly new biomass is being produced.

Cover the solution and retrieve these four definitions before checking the options:

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