Updated November 2026. These KCSE 2026 Biology Paper 2 (231/2) predicted questions are built from past-paper trends: we ranked the topics that past KCSE Biology Paper 2 papers test most often, then wrote original practice questions on them. They are not leaked, official or guaranteed questions, and this site is not linked to KNEC or KICD. Use them to practise the areas most likely to appear, alongside your full syllabus revision.
KCSE Biology 231/2 prediction: most commonly tested topics
The ranking below comes from the topic coverage of past KCSE papers, as summarised in our paper guides. It is a ranking, not an exact count: exam papers change every year.
| Rank | Topic | How it is usually tested |
|---|---|---|
| 1 | Genetics | Monohybrid crosses, sex linkage, mutations, blood groups |
| 2 | Ecology | Food chains, energy flow, population estimation, adaptations |
| 3 | Reproduction | Flowers, pollination, human reproduction, fertilisation |
| 4 | Coordination and response | Nervous system, reflex arc, eye, ear, hormones, plant tropisms |
| 5 | Excretion and homeostasis | Kidney, skin, liver, blood sugar and temperature control |
| 6 | Support and movement | Skeleton, joints, muscles, support in plants |
| 7 | Evolution | Evidence for evolution, natural selection |
Free sample: 3 KCSE 2026 Biology Paper 2 predicted questions
Q1. In a cross between two heterozygous tall pea plants (Tt), find the phenotypic ratio of the offspring.
Marking scheme
TT, Tt, Tt, tt: 3 tall : 1 short.
Q2. In a capture-recapture study, 40 grasshoppers were marked and released. Later 50 were caught, of which 10 were marked. Estimate the population.
Marking scheme
40 × 50 / 10 = 200 grasshoppers.
Q3. Draw (describe) the path of a simple reflex arc.
Marking scheme
Receptor → sensory neurone → relay neurone in the spinal cord → motor neurone → effector (muscle or gland).
Full set: 17 more predicted questions with marking scheme
17 more predicted questions with full marking schemes are locked. They cover every topic in the table above.
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Frequently asked questions
Are these the real KCSE 2026 Biology Paper 2 questions?
No. Nobody outside KNEC knows the real questions, and any site claiming a leak is lying or breaking the law. These are original practice questions written by the CBC Guide team, predicted from the topics past KCSE papers test most often.
Which topics come up most in KCSE Biology Paper 2 (231/2)?
The most commonly tested areas in past papers are Genetics, Ecology, Reproduction, Coordination and response. The full ranked list is in the table above.
How do I get the full set of predicted questions?
The first 3 questions are free. The remaining 17, each with a marking scheme, unlock with the KSh 20 Day Pass or the KSh 500 Monthly Pass, paid by M-Pesa. The passes do not auto-renew.
How should I use predicted questions in the last days before the exam?
Answer each question under time, mark it with the scheme, then go back to your notes for any topic you got wrong. Do not skip topics that are not on this list, because KNEC can test any part of the syllabus.
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