Grade 7 Science practice sheet
Saskatchewan Curriculum · from Gradelings · Name: ______________________
Question 1
Lake water warms during a heat wave and holds less dissolved oxygen. How might this affect fish?
- Fish are not affected at all
- Fish breathe more easily
- Fish that need a lot of oxygen may struggle to survive
- All fish grow faster
Show answer
Fish that need a lot of oxygen may struggle to survive
Hint: Warm water holds less dissolved oxygen, an abiotic factor that fish need.
Question 2
A grasshopper eats grass. A frog eats the grasshopper. The frog is a…
- secondary consumer
- producer
- decomposer
- primary consumer
Show answer
secondary consumer
Hint: A primary consumer eats producers. A secondary consumer eats primary consumers.
Question 3
Put the stages of primary succession in order.
- 🪨Bare rock
- 🌾Soil builds up and grasses grow
- 🌲A mature forest develops
- 🌱Shrubs and small trees take over
Show answer
Bare rock → Soil builds up and grasses grow → Shrubs and small trees take over → A mature forest develops
Hint: Bare rock, then lichens and mosses, then soil and grasses, then shrubs, then forest.
Question 4
What does the data suggest?
Phosphorus in a lake (mg/L). A limit on phosphorus in detergents began in 2002. Year Phosphorus 2001 0.09 2006 0.06 2011 0.04 2016 0.03 - Phosphorus has not changed
- Phosphorus has risen since the limit began
- Phosphorus has fallen since the limit began, so the limit may be helping
- The data prove that nothing else could be involved
Show answer
Phosphorus has fallen since the limit began, so the limit may be helping
Hint: Compare 2001, before the limit, with the later years. Data can suggest a link, but other causes should be ruled out before saying for sure.
Question 5
Water as ice, as liquid water and as water vapour has the same kind of particle. What differs in each state?
- Whether the water is pure
- How the particles are arranged and how they move
- The number of different substances
- The kind of particle
Show answer
How the particles are arranged and how they move
Hint: Changing state changes the arrangement and motion, not the kind of particle.
Question 6
At 20 °C, at most 36 g of Substance X dissolves in 100 mL of water. You stir 26 g of Substance X into 100 mL of water at 20 °C. What do you get?
- a saturated solution with solid left at the bottom
- a saturated solution with nothing left undissolved
- an unsaturated solution
Show answer
an unsaturated solution
Hint: 26 g is less than the 36 g limit, so more could still dissolve: the solution is unsaturated.
Question 7
Which statement correctly describes heat and temperature?
- Heat and temperature mean exactly the same thing
- Heat is energy that moves from warmer to cooler; temperature measures average particle motion
- Heat measures how fast something is moving overall
- Temperature is the energy moving between objects
Show answer
Heat is energy that moves from warmer to cooler; temperature measures average particle motion
Hint: Heat is a transfer of energy. Temperature is a measure of an object's particles.
Question 8
A lizard lies on a sun-warmed rock and warms up. Which type of heat transfer is warming it from below?
- conduction
- convection
- evaporation
- radiation only
Show answer
conduction
Hint: Heat passes directly from the rock to the lizard where they touch.
Question 9
Put these events in Earth's history in order, oldest first.
- 🦠First simple life appears in the oceans
- 🌍Earth forms
- ☄️Dinosaurs (except birds) die out
- 🧍Modern humans appear in Africa
Show answer
Earth forms → First simple life appears in the oceans → Dinosaurs (except birds) die out → Modern humans appear in Africa
Hint: Earth forms: about 4.6 billion years ago. First simple life appears in the oceans: at least 3.5 billion years ago. Dinosaurs (except birds) die out: about 66 million years ago. Modern humans appear in Africa: about 300,000 years ago.
Question 10
Biotic or abiotic? Sort each part of an ecosystem.
Sort into: 🌱 biotic (living) · 🪨 abiotic (non-living)
- 🪨a boulder
- 🐸a frog
- 💧water in a stream
- 🌬️wind
- 🌡️the temperature
- 🦠bacteria in the soil
- 🍄a mushroom
- 🦫a beaver
Show answer
🌱 biotic (living): a frog, bacteria in the soil, a mushroom, a beaver · 🪨 abiotic (non-living): a boulder, water in a stream, wind, the temperature
Hint: Biotic parts are living things (plants, animals, fungi, bacteria). Abiotic parts are the non-living things, such as sunlight, water, air, rock and temperature.
Answer key
- 1. Fish that need a lot of oxygen may struggle to survive (Ecosystems)
- 2. secondary consumer (Food Chains & Energy)
- 3. Bare rock → Soil builds up and grasses grow → Shrubs and small trees take over → A mature forest develops (Cycles & Succession)
- 4. Phosphorus has fallen since the limit began, so the limit may be helping (People & Ecosystems)
- 5. How the particles are arranged and how they move (Particles & Mixtures)
- 6. an unsaturated solution (Solutions & Separating)
- 7. Heat is energy that moves from warmer to cooler; temperature measures average particle motion (Heat & Particles)
- 8. conduction (Moving Heat)
- 9. Earth forms → First simple life appears in the oceans → Dinosaurs (except birds) die out → Modern humans appear in Africa (Restless Earth)
- 10. 🌱 biotic (living): a frog, bacteria in the soil, a mushroom, a beaver · 🪨 abiotic (non-living): a boulder, water in a stream, wind, the temperature (Ecosystems)
Want more than 10 questions?
In Gradelings the questions change every time and adjust to your child, with hints and kind feedback. See all science units.