NEB Class 11 • Biology • Biota and Environment • Practice Set

Air, Water & Soil Pollution & Pesticides Practice Set: NEB 11 Biology

Master Air, Water and Soil Pollution and Pesticides through clear concepts, representations, a reliable answer method and exam-focused practice.

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Concepts · Worked reasoning · NEB practice

Quick answer: Pollution occurs when contaminants or energy alter environmental quality and biological function; risk depends on hazard, dose, exposure route, persistence and vulnerability.

Worked practice

Build the result from meaning, not memory

Pollution occurs when contaminants or energy alter environmental quality and biological function; risk depends on hazard, dose, exposure route, persistence and vulnerability.

Worked example

Fertilizer runoff can drive eutrophication and oxygen depletion, while persistent pesticides may concentrate in organisms and increase at higher trophic levels.

The governing relationship is Use source→pathway→exposure→effect→control; distinguish bioaccumulation within an organism from biomagnification across trophic levels. Check the convention, geometry or boundary condition before calculation.

Independent practice ladder

  1. Define the key physical quantities and give their SI units.
  2. Draw and label the relevant wave, ray, mode or energy diagram.
  3. Recalculate the worked example after changing one input by a factor of two.
  4. Explain the result without equations.
  5. Create a Nepal-relevant situation such as a classroom speaker, musical pipe, optical slit or thermal machine.
  6. Compare two cases and predict the larger output before calculating.
  7. Find and repair one deliberately wrong sign, node or unit.
  8. Write a three-mark answer and a five-mark answer.

Answer protocol: diagram → known data → principle → symbolic equation → SI substitution → result → physical check. Calling every chemical equally toxic, confusing ozone depletion with air pollution generally, or recommending pesticides without dose and ecological trade-offs.

NEB answer method

Model → evidence → equation → check

First identify the system and what the question asks. Label the diagram, apparatus or reaction with SI quantities, then state the principle before selecting an equation. Solve symbolically where possible and check units, limiting cases and chemical or physical meaning.

StageQuestionEvidence
ModelWhat is idealised?Assumption stated
RepresentationWhich diagram fits?Labels or balanced equation
CalculationWhich relation follows?Symbols then SI values
EvaluationDoes it make sense?Unit, sign and trend check

Make the idea concrete in Nepal

Connect the model to a school laboratory, household technology, health, environment, energy or local material. The example should clarify the science rather than merely mention a place. Compare a prediction with an observation and record uncertainty.

Review the NEB Class 11 Biology revision roadmap and the complete Biology guide. For online or physical tuition, call 9846662070.

Questions students ask about Air, Water and Soil Pollution and Pesticides

What is the central idea of Air, Water and Soil Pollution and Pesticides?

Pollution occurs when contaminants or energy alter environmental quality and biological function; risk depends on hazard, dose, exposure route, persistence and vulnerability.

Which equation should I remember?

Use source→pathway→exposure→effect→control; distinguish bioaccumulation within an organism from biomagnification across trophic levels.

How should I begin a numerical?

Draw the situation, list known quantities in SI units, choose the governing relation symbolically, substitute once and finish with a unit and reasonableness check.

What is a common exam mistake?

Calling every chemical equally toxic, confusing ozone depletion with air pollution generally, or recommending pesticides without dose and ecological trade-offs.

How can I practise this topic?

Alternate one concept explanation, one diagram and two numericals. Revisit errors after a day instead of only rereading the solution.

Where can I get tuition support?

For online or physical KTM Tuition classes, call 9846662070. After Grade 12, the MKS Education panel below gives preparation and pre-counselling contacts.

Frequently asked questions

References and next steps

Scope checked against CDC Nepal; concept support from an institutional reference and OpenStax Science. Continue with the Air, Water and Soil Pollution and Pesticides cluster.

NEB +2 tuition support

Ask about online or physical tuition

For focused Class 11 and Class 12 subject tuition, lesson clarification, worked-example practice and exam preparation, call 9846662070. Class mode, timetable, teacher availability and fees should be confirmed directly before enrolment.

Call 9846662070