Cumulative review

Ten questions of mixed difficulty, covering Heat and temperature, Interactions and ecosystems, Plants for food and fibre, Structures and forces. Print it, or work through it on screen — the answer key starts on its own page.

All worksheets

Cumulative review

Science 7 · maddyhelps.com

Name
Date
Score: / 10

Circle the best answer for each question. Show your work in the space provided.

Engineers say a crowd jumping in time at a concert is harder on a balcony than the same crowd standing still. Why?
1. a) A crowd standing still puts no force on the balcony at all
2. b) Jumping adds mass to each person, so the crowd weighs more
3. c) Jumping turns the compression in the balcony into torsion
4. d) A moving, dynamic load can push harder than the same weight at rest
On a cold, clear winter day, you feel the Sun warm your face even though the air around you is cold. The energy reaches you mainly by
1. a) conduction
2. b) evaporation
3. c) convection
4. d) radiation
In a pond, water fleas eat algae, small fish eat water fleas, and herons eat small fish. Which of these is the producer?
1. a) The water fleas
2. b) The algae
3. c) The small fish
4. d) The herons
Which of these energy sources is renewable?
1. a) Wind
2. b) Oil
3. c) Natural gas
4. d) Coal
A bathtub holds water at 40 °C, and a mug holds water at 80 °C. Which statement is correct?
1. a) The mug's particles move faster, but the bathtub holds more thermal energy
2. b) Both hold the same thermal energy, because both are just water
3. c) The bathtub's particles move faster, because it holds more water
4. d) The mug holds more thermal energy, because its water is hotter
A farmer finds a few aphids on her crop, along with ladybugs, which eat aphids. Which plan follows integrated pest management?
1. a) Keep counting the aphids, and spray only if they pass a set level
2. b) Spray the whole field every week, whether aphids are seen or not
3. c) Spray at once to kill every insect in the field, ladybugs included
4. d) Double the usual dose of pesticide so the aphids die sooner
In a boreal forest, snowshoe hares eat willow shrubs, and lynx eat snowshoe hares. If a disease kills most of the lynx, what will most likely happen next?
1. a) The willows are not affected, since lynx never eat them
2. b) More willow grows, since the hares have less to eat
3. c) Fewer hares survive, since their predator is gone
4. d) More hares survive, and more willow gets eaten
Mushrooms and other fungi growing on a fallen log slowly break it down and return its nutrients to the soil. They are acting as
1. a) herbivores
2. b) producers
3. c) scavengers
4. d) decomposers
You climb out of a lake on a warm, breezy day and feel cold until you dry off. What is the main reason?
1. a) The breeze carries cold onto your skin from the lake's surface
2. b) Water evaporating from your skin takes thermal energy from your body
3. c) The lake water on your skin is much colder than the air around you
4. d) Water on your skin blocks the Sun's radiation from reaching you
A house in Alberta has large windows facing south and a thick concrete floor just inside them. How does this design help heat the house?
1. a) The concrete brings heat up from deep underground into the rooms
2. b) The floor absorbs sunlight by day and gives off the heat after dark
3. c) The south windows let warm outdoor air flow into the house
4. d) The concrete floor produces heat of its own once the sun goes down

Answer key · Cumulative review

Science 7 · maddyhelps.com

d) A moving, dynamic load can push harder than the same weight at rest — A load that moves or changes is dynamic: each landing pushes down with more force than the person's weight, and jumping in rhythm can make a structure sway more and more. The people's mass never changes; the forces they put on the balcony do.
d) radiation — Radiation carries energy as waves that need no particles, which is how sunlight crosses empty space to reach Earth. Conduction and convection both need matter to carry the energy, and the cold air around you is clearly not what is warming your face.
b) The algae — A producer makes its own food using energy from sunlight, and in this chain only the algae can do that. The water fleas are the first animals in the chain, but they are consumers: they get their energy by eating the algae.
a) Wind — A renewable source is replaced naturally as fast as we use it, and the wind keeps blowing because the Sun keeps heating the air unevenly. Coal, oil and natural gas formed from ancient living things over millions of years, so what we burn is gone for good on any time scale that matters to us.
a) The mug's particles move faster, but the bathtub holds more thermal energy — Temperature is the average motion of the particles, so the hotter mug wins on that. But the bathtub has vastly more particles, and adding up all of their energy gives far more in total, which is why a tub of warm water can melt far more snow than a mug of hot water.
a) Keep counting the aphids, and spray only if they pass a set level — Integrated pest management means watching the pest, using natural enemies and other methods first, and spraying only when the numbers get high enough to do real damage. Spraying on a schedule kills the ladybugs that are controlling the aphids for free, and helps the aphids become resistant.
d) More hares survive, and more willow gets eaten — With fewer lynx hunting them, more hares survive, and more hares eat more willow. A change at one level of a food web passes along the chain, so it reaches the willows even though a lynx never eats a plant.
d) decomposers — Decomposers break dead matter down into nutrients that plants can take up again, which is how matter gets recycled. A scavenger, such as a raven, eats dead animals but leaves the final breakdown to decomposers, and fungi are not producers, because they cannot make food from sunlight.
b) Water evaporating from your skin takes thermal energy from your body — To evaporate, water particles need energy, and they take it from your skin, so your skin cools; a breeze speeds up evaporation, which is why you feel colder in the wind. Cold is not something that flows onto you: it is only less thermal energy.
b) The floor absorbs sunlight by day and gives off the heat after dark — In Canada the Sun crosses the southern part of the sky, so south windows catch the most sunlight, and the dense floor stores that energy and releases it slowly at night. The concrete makes no heat of its own, it only stores the Sun's; this is passive solar heating, which needs no pumps or fans.