Skip to content

The table below is a… (Class 12 Biology SQP 2026-27, Q21A)

questionbuddy.in/q/cbse-12-biology-2026-27-sqp-q21a-table-hypothetical-data-seasonal-temperatures

BiologyCBSE Class 12 · Sample paper, session 2026-27 · 2 marks · Very short answer

CBSE Class 12 Biology sample paper 2026-27: question 21(A)

From the official CBSE sample question paper for 2026-27, section B, question 21(A), for 2 marks. Try it first; the hints and our step-by-step solution are below.

Q21(A) · 2 marks · Very short answerCompetency-basedEcosystem

The table below is a hypothetical data on Seasonal Temperatures seen over two different zones

RegionTemp. in Spring (C)Temp. in Summer (C)Temp. in Autumn (C)Temp. in Winter (C)Primary Productivity (GPP) (g/m/year)Respiration (R) (g/m/year)
Region X2728272635001300
Region Y12201442000800

I. Justify which region will have greater species diversity based on the given data?
II. Calculate the net primary productivity (NPP) of the region mentioned in (I) and give its significance?

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2026-27.

Hints

Open one hint at a time and try again before the next.

Hint 1

Which region has less seasonal variation and higher productivity?

Hint 2

Net productivity is gross productivity minus respiration losses.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. I. Region X (a tropical region) will have greater species diversity. Its temperature is nearly constant through the year (26–28 °C), giving stable, predictable conditions that favour niche specialisation. Its productivity is also higher (GPP 3500 vs 2000 g/m²/year).

    1 mark

  2. II. NPP = GPP − R = 3500 − 1300 = 2200 g/m²/year.
    Significance: NPP is the biomass available for consumption by heterotrophs (herbivores and decomposers).

    1 mark

Answer: I. Region X. II. NPP = 2200 g/m²/year; it is the biomass available to heterotrophs.

Where the marks are

  • Region X, justified by near-constant temperature or higher productivity (1 mark)
  • NPP = 3500 − 1300 = 2200 g/m²/year, with its significance (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Ecosystem, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2026-27: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.