The six-question structure, command words, data-analysis and graph skills, how to write extended answers — then a full 100-mark mock paper with mark schemes.
6 narrated scenes. Press play, listen and read along — the points appear as they are explained. Use ‹ Prev / Next › or the scene bar to jump to any scene.
Paper 02 is half your grade. Examiners reward points clearly stated — here’s how to state them.
Narration uses your device’s built-in voice. No sound? Switch to “Captions only” — the captions advance on their own.
Copy these into your notebook in your own words — that is how they stick.
6 compulsory questions, 100 marks, 2 h 30 min, 50% of grade. Q1 data analysis 25 marks; Q2–3 structured; Q4–6 extended response (15 each).
State/list = facts; describe = what happens; explain = reasons; discuss = both sides; suggest = apply; compare = similarities & differences.
One clear point per mark; explain marks come as point + reason.
Title, labelled axes with units, good scale, accurate plots, key for >1 line.
Show working, include units, round sensibly.
Large, pencil, clean lines, ruled labels, title and magnification.
The CXC specimen Paper 02 and mark scheme are printed in the syllabus, pp. 104–136.
8 items modelled on real CSEC Paper 1 questions. Choose one answer for each, then check. Aim for 80% or better.
Write full answers, then reveal the mark scheme and tick the points you earned (100 marks in total). Your answers are saved on this device.
Question 1 [25 marks]
A class studied a small coastal area between a pond and a busy road. They used a 1 m² quadrat behind the mangroves. Numbers of a small flowering shrub in ten random quadrats were: 5, 2, 3, 2, 2, 1, 2, 1, 3, 1. In the pond they recorded feeding: crab (decaying plant matter); guppy (mosquito larvae, tadpoles); water bird (guppy, frog, crab); snail (algae, water weed); mosquito larvae (decaying matter); frog (dragonfly, mosquito larvae); tadpoles (water weed); water weed and algae make their own food. Frog counts were: 2019 — 125, 2020 — 75, 2021 — no data (hurricane), 2022 — 110, 2023 — 80, 2024 — 35, 2025 — 5.
(a) Name TWO other pieces of apparatus needed to study how species change from the water’s edge to the road, and describe how EACH would be used. [4]
(b) State ONE precaution when using the quadrat, and calculate the density of the shrub (show working). [3]
(c) Construct a food web using TEN of the organisms (describe it in words if typing). [3]
(d) Explain why there are rarely more than four trophic levels, and name TWO abiotic factors affecting the pond. [4]
(e) Plot the frog data as a line graph (describe the key features you would include). [4]
(f) Account for the trend in the frog population before and after the hurricane. [3]
(g) Suggest why it is useful to study frogs, and why these frogs cannot breed with frogs from another coast 10 km away. [4]
Question 2 [15 marks]
The human eye.
(a) Name the parts that: (i) hold the lens in place; (ii) change the shape of the lens; (iii) control pupil size; (iv) give the sharpest vision; (v) carry impulses to the brain; (vi) focus light finely. [6]
(b) What term describes rods and cones? Explain how a dry, thickened cornea (severe vitamin A lack) affects sight. [3]
(c) Name the defect and correcting lens when (i) the image falls behind the retina; (ii) the image falls in front of the retina. [4]
(d) Suggest TWO precautions when using contact lenses. [2]
Question 3 [15 marks]
Flower Q has large petals, anthers inside the flower and many ovules; Flower R has no petals, long filaments and feathery stigmas.
(a) State the likely pollinating agent of Flower R and give TWO reasons. [3]
(b) Flower Q has many ovules. Describe one feature of its mature fruit and why it helps the species survive. [2]
(c) Q’s seeds are found far from the parent but are not dispersed by animals or water. Explain how; suggest why some plants have no dispersal of seeds. [3]
(d) Describe the events after pollination that lead to seed formation. [4]
(e) State TWO ways animals help flowering plants. [3]
Question 4 [15 marks]
Gaseous exchange in humans and flowering plants.
(a) Describe how air is moved into the lungs, and why gaseous exchange is important. [6]
(b) Compare the gaseous exchange surfaces in humans and flowering plants, naming each. [5]
(c) Explain TWO ways smoking reduces the efficiency of gaseous exchange. [4]
Question 5 [15 marks]
Mosquito-borne disease.
(a) Name a pathogen and the disease it causes. Describe the mosquito’s role in transmission and suggest TWO social implications of an outbreak. [8]
(b) Explain THREE reasons it is important to study the mosquito life cycle to control the disease. [5]
(c) Explain why some people show no symptoms when bitten by an infected mosquito. [2]
Question 6 [15 marks]
Natural selection, artificial selection and genetic engineering.
(a) State what is meant by natural selection and explain why genetic variation is important to it. [4]
(b) Humans have bred many dog breeds. Explain TWO ways this differs from natural selection and give TWO disadvantages to the species. [4]
(c) State what genetic engineering is, discuss TWO possible negative outcomes and THREE benefits. [7]
Everything in this lesson is based on these parts of the CXC syllabus and papers.
This lesson’s structured section IS a full 100-mark mock Paper 02. For exam conditions, set a 2 h 30 min timer and answer all six questions before revealing any mark scheme.