Week 15 · Term 1 review (Units 1–4) and Darslab’s own review tasks · 3 lessons
3
Review: photosynthesis, respiration and Earth’s changes
Science Prep 2 Term 1, Units 1–4: Review
GoalReview photosynthesis, cellular respiration, plate tectonics, minerals, soil and resources with new mixed tasks.
New words
photosynthesis and respiration · two linked processes: one stores energy in glucose, the other releases itplate boundary · where two tectonic plates meetnon-renewable · takes millions of years to form
Explanation
From Units 3 and 4. Photosynthesis happens in chloroplasts: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ with light and chlorophyll; it is anabolic. Cellular respiration happens in all living cells, in the cytoplasm and mitochondria: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy; it is catabolic. The rate of photosynthesis is set by the limiting factor: light, carbon dioxide or temperature. Wegener’s continental drift is explained by plates driven by mantle convection. Divergent plates move apart, convergent plates collide, transform plates slide past each other. Earthquakes and volcanoes mostly occur along these boundaries; meteorites are rocks from space that reach the ground. A mineral is a natural, solid, non-living substance with a crystal structure and a definite composition. Soil is weathered rock plus humus; transported soil comes from elsewhere, sedentary soil stays where the rock weathered. Minerals and fossil fuels are non-renewable.
Photosynthesis
Cellular respiration
inputs
CO₂, H₂O, light
glucose, O₂
outputs
glucose, O₂
CO₂, H₂O, energy
where
chloroplasts
cytoplasm and mitochondria
type
anabolic
catabolic
Worked examples
Read a short invented graph: the rate rises with light, from 0 to 50, then stays at 50 from light 5 to 8. At light 7, which factor is limiting? Not light: more light does not raise the rate. Carbon dioxide or temperature is the limit.
Name the boundary from the description: (a) two plates pull apart and a new sea floor forms (divergent); (b) an oceanic plate goes under a continental plate and a mountain chain rises (convergent); (c) two plates grind sideways past each other (transform).
Sort: quartz (mineral), coal (not: organic), halite (mineral), plastic (not: made by people), ice (mineral). Soil: Nile Delta (transported), Mariout (sedentary). Resources: oil (non-renewable), sunlight (renewable).
Class activity
Link the cycles. Draw a loop with two big boxes, photosynthesis and respiration, and arrows showing glucose, oxygen, carbon dioxide and water passing between them. Add one box for the Sun and one for the cell’s energy use. Then write three sentences on plates, earthquakes and volcanoes in your own words, using divergent, convergent and transform. Do not predict earthquakes.
Practice
1
Write both equations: photosynthesis and cellular respiration.
