Grade 7 Science: 10 Free Practice Questions

Answer: to release energy for the cell
Mitochondria carry out cellular respiration.

Answer: 20 m/s
Wave speed = frequency × wavelength = 4 Hz × 5 m = 20 m/s. Distractors come from adding or subtracting the values instead of multiplying.

Answer: solar energy
Sunlight is continuously available.

Answer: data from the experiment
Conclusions must be supported by evidence.

Answer: fight infection
White blood cells are part of the immune system.

Answer: Weathering
Weathering is the process by which rocks are broken down into smaller pieces through mechanical (physical) or chemical processes caused by exposure to environmental elements such as water, ice, and wind.

Answer: The atoms are rearranged into new substances, such as carbon dioxide, water vapor, and ash, rather than being destroyed
The law of conservation of mass means atoms are never created or destroyed in a chemical reaction; when wood burns, its atoms recombine into new substances such as carbon dioxide, water vapor, and ash.

Answer: A renewable resource can be replenished naturally within a relatively short period, while a nonrenewable resource takes millions of years to form
Renewable resources, such as solar energy or timber, can be replenished on a human timescale, while nonrenewable resources, such as coal and oil, form over millions of years and are depleted much faster than they are replaced.

Answer: cell, tissue, organ, organ system
Cells form tissues, tissues form organs.

Answer: The particles gain kinetic energy and move faster, overcoming some of the forces holding them in a fixed position
Heating increases the average kinetic energy of particles, causing them to vibrate and move more freely, which weakens the attractive forces that hold particles in the fixed arrangement of a solid.