Subscribe

9th grade · Science · Unit 5 of 10

Photosynthesis & Respiration

How cells make and use energy

What your child practices

The reactants, products and location of photosynthesis and cellular respiration, why they are complementary, and how they link plants, animals and the carbon cycle.

Alaska content standards learning standard: HS-LS1-5; HS-LS1-7 · photosynthesis and cellular respiration

How we explain it

Children can open this short lesson before they practice.

  1. Photosynthesis (in chloroplasts): carbon dioxide + water + light → glucose + oxygen.
  2. Cellular respiration (in mitochondria): glucose + oxygen → carbon dioxide + water + energy.
  3. The products of each are the reactants of the other, which cycles carbon.

Example: Which process releases oxygen: photosynthesis or respiration? Respiration uses oxygen. Photosynthesis gives it off. Answer: photosynthesis

Photosynthesis & Respiration in Alaska

In the Alaska content standards, this is unit 5 of 10 in 9th grade Science, after Electrons & Compounds and before The Periodic Table.

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: Alaska Department of Education and Early Development

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    What are the products of photosynthesis?

    • glucose and oxygen
    • carbon dioxide and glucose
    • carbon dioxide and water
    • water and oxygen only

  2. Question 2

    Where in a cell is most of the energy released by cellular respiration?

    • chloroplasts
    • the nucleus
    • mitochondria
    • the cell membrane

  3. Question 3

    Large forests are called carbon sinks because they…

    • stop the water cycle
    • take in more carbon dioxide than they release over time
    • produce no oxygen
    • release more carbon than they take in

  4. Question 4

    What are the reactants of cellular respiration?

    • carbon dioxide and water
    • light and water
    • glucose and carbon dioxide
    • glucose and oxygen

  5. Question 5

    Which gas released by photosynthesis do animals use in cellular respiration?

    • nitrogen
    • carbon dioxide
    • oxygen
    • hydrogen

  6. Question 6

    Which words summarize photosynthesis?

    • oxygen + water → carbon dioxide + glucose
    • glucose + carbon dioxide → water + oxygen
    • carbon dioxide + water + light energy → glucose + oxygen
    • glucose + oxygen → carbon dioxide + water + energy

More 9th grade