Grade 8 · Science · Unit 3 of 13
Cells & Life Processes
Organelles, photosynthesis and respiration
What your child practises
The cell theory, what organelles do in plant and animal cells, how photosynthesis and respiration are connected, osmosis, and how cells form tissues, organs and organ systems.
Ontario Curriculum expectation: B2.1–B2.4, B2.6 · the cell theory, organelles, plant and animal cells, diffusion and osmosis, and cells, tissues, organs and systems
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Which is the correct order from smallest to largest?
- organ → cell → tissue → organ system
- tissue → cell → organ system → organ
- cell → tissue → organ → organ system
- organ system → organ → tissue → cell
Show answer
cell → tissue → organ → organ system
Hint: Cells form tissues, tissues form organs, and organs work together in organ systems.
Question 2
How are photosynthesis and cellular respiration related?
- They happen only at night.
- They are the same process.
- They happen only in animals.
- The products of one are the inputs of the other.
Show answer
The products of one are the inputs of the other.
Hint: Photosynthesis makes glucose and oxygen. Respiration uses glucose and oxygen.
Question 3
What does the cell membrane do?
- Gives plant cells their green colour
- Stores the cell's DNA
- Makes sugar from sunlight
- Controls what enters and leaves the cell
Show answer
Controls what enters and leaves the cell
Hint: The membrane is a flexible boundary that lets some materials in and out.
Question 4
Where does photosynthesis happen in a plant cell?
- chloroplasts
- ribosomes
- mitochondria
- nucleus
Show answer
chloroplasts
Hint: Chloroplasts contain chlorophyll, which captures light energy.
Question 5
What are the inputs of photosynthesis?
- oxygen and sugar
- oxygen and water
- sugar and light
- carbon dioxide, water and light energy
Show answer
carbon dioxide, water and light energy
Hint: Plants use CO₂, water and light to make glucose (sugar) and oxygen.
Question 6
Which organelle controls the cell's activities and holds its DNA?
- cell wall
- vacuole
- mitochondrion
- nucleus
Show answer
nucleus
Hint: The nucleus is like the control centre of the cell.