8th grade · Science · Unit 6 of 13
Cells & Life Processes
Organelles, photosynthesis and respiration
What your child practices
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.
Texas Essential Knowledge and Skills (TEKS) teks student expectation: 8.13(A) · the functions of cell parts such as the membrane, nucleus, mitochondria and chloroplasts
How we explain it
Children can open this short lesson before they practice.
- Cell theory: all living things are made of cells, and cells come from other cells.
- Chloroplasts do photosynthesis; mitochondria do respiration. The products of one are the inputs of the other.
- Osmosis is water moving across a membrane. Cells form tissues, organs and systems.
Example: What are the products of photosynthesis? Plants use light, water and carbon dioxide. They make sugar and give off a gas. Answer: glucose and oxygen
Cells & Life Processes in Texas
In the Texas Essential Knowledge and Skills (TEKS), this is unit 6 of 13 in 8th grade Science, after Cycles & Succession and before Genes & Heredity.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Texas Education Agency (TEA)
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 structure is found in plant cells but NOT animal cells?
- cell wall
- cell membrane
- nucleus
- mitochondria
cell wall
Hint: Plant cells have a rigid cell wall outside the membrane, plus chloroplasts.
Question 2
Which is the correct order from smallest to largest?
- organ → cell → tissue → organ system
- cell → tissue → organ → organ system
- tissue → cell → organ system → organ
- organ system → organ → tissue → cell
cell → tissue → organ → organ system
Hint: Cells form tissues, tissues form organs, and organs work together in organ systems.
Question 3
What are the products of photosynthesis?
- carbon dioxide and water
- glucose (sugar) and oxygen
- water and energy
- carbon dioxide and oxygen
glucose (sugar) and oxygen
Hint: Glucose stores energy for the plant, and oxygen is released.
Question 4
Found only in plant cells, or in both plant and animal cells? Sort each cell part.
Sort into: 🌿 Plant cells only · 🐾 Plant and animal cells
- ⚙️ribosomes
- 🧱cell wall
- 🫧cell membrane
- 🥣cytoplasm
- 💧large central vacuole
- 🟢chloroplasts
- 🔋mitochondria
🌿 Plant cells only: cell wall, large central vacuole, chloroplasts · 🐾 Plant and animal cells: ribosomes, cell membrane, cytoplasm, mitochondria
Hint: Chloroplasts, the cell wall and the large central vacuole are only in plant cells. The nucleus, mitochondria, cell membrane, cytoplasm and ribosomes are in both.
Question 5
What are the products of cellular respiration?
- glucose and oxygen
- only sugar
- only oxygen
- energy, carbon dioxide and water
energy, carbon dioxide and water
Hint: Cells use glucose and oxygen to release energy, making carbon dioxide and water.
Question 6
Where does photosynthesis happen in a plant cell?
- chloroplasts
- mitochondria
- nucleus
- ribosomes
chloroplasts
Hint: Chloroplasts contain chlorophyll, which captures light energy.