Every year, over two million teenagers walk into CBSE Class 10 board exam halls carrying the same quiet mix of bravado and panic — the first national test that feels like it will “decide everything”. Official records suggest around 26.6 lakh candidates are expected to appear for CBSE Class 10 in 2026. In that crowd, Science carries weight beyond the marks it awards. It often decides what students can choose next. In 2026, CBSE Class 10 Science exam is scheduled for 25th February. The paper is divided into 3 sections: Biology, Chemistry and Physics. With the exam approaching, students should be clear about the paper structure, marking scheme and the demands of each section in the Science paper. Here, we focus on Biology, the segment where marks are often won through precision, diagrams and NCERT-aligned answers.
CBSE Class 10 Biology section: Start with the basics
In the CBSE Class 10 Science exam, Biology carries 30 marks out of the 80-mark theory paper. It spans through 5 chapters:
- Life Processes
- Control and Coordination
- How Do Organisms Reproduce?
- Heredity
- Our Environment
Understand the process, don’t just memorise
Biology rewards students who know how things work, not those who simply remember what the textbook says. Examiners look for sequence, cause-and-effect, and the right scientific terms placed at the right places, in an answer. Ms. Reema Chawra, Biology faculty at Ryan International School, Delhi, says, “In Biology, conceptual clarity and precise terminology are the keys to scoring well.” She also adds a crucial warning for last-minute revision: “Ensure you understand processes (like photosynthesis, fertilization, pollination or translocation) instead of memorizing them mechanically.”
CBSE Class 10 Biology: Draw to score
In Biology, diagrams are not “extra”. They are often the most efficient way to show the examiner you understand structure, function and sequence without wasting time on long explanations. A clean diagram with accurate labels can rescue an otherwise average answer. That is why, Chawra insists, “Practise labelled diagrams such as the human heart, nephron, and male and female reproductive systems. These often carry high weightage.” She adds that revision works best when it is visual. “Make concise notes with flowcharts and diagrams for each chapter,” suggests Chawra.
Sticking to NCERT is a must
In Biology, accuracy matters more than range. Many students revise from multiple sources and still lose marks because the final answer does not match the language CBSE expects. The examiners are not testing how many facts you know. They are checking whether you can state the concept cleanly, with the right terms, in the right order. That is why Chawra advises, “Focus on NCERT line-by-line reading and previous years’ question papers.” She also flags what typically gets missed during rushed revision: NCERT-based definitions and examples. “Even a single missed term can cost marks,” she cautions.
Start with answers you are confident about
In a board exam, momentum is vital. The first stretch decides whether you write with control or chase time for the next three hours. Starting with questions you can do well is not playing safe, it is how you lock your pace, calm your nerves, and stop avoidable errors from creeping in. Chawra puts it plainly, “During the exam, begin with questions you are confident about. It boosts your morale and sets a positive pace.” After that, make it easy for the examiner to award marks. “Write neat, well-structured answers with proper subheadings and underlined keywords. presentation makes a strong impact,” she adds.
Stop overwriting, start scoring
Biology does not reward length, it rewards precision. Students often write full explanations and still lose marks because the answer does not land the exact terms the examiner is scanning for. “Many students lose marks by writing long, descriptive answers instead of using keywords,” explains Chawra. The other silent mark-cutter is carelessness. A correct concept can still drop marks if terminology is misspelt or a diagram label is incomplete. “Avoid spelling errors in biological terms and incomplete labelling in diagrams,” she cautions.
