maddyhelps

Science 10

Science 10 · Worksheets

Mixed review · Cells and global systems

Ten questions of mixed difficulty, covering Cells, Global systems. Print it, or work through it on screen — the answer key starts on its own page.

All worksheets

Mixed review · Cells and global systems

Science 10 · maddyhelps.com

Name
Date
Score
/ 10

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

  1. Most of a cell's ATP is produced in the

    1. a) cell wall
    2. b) mitochondrion
    3. c) chloroplast
    4. d) nucleus

  2. Photosynthesis and cellular respiration are closely linked because

    1. a) both happen in the chloroplast
    2. b) neither uses oxygen
    3. c) the products of each are the reactants of the other
    4. d) both destroy energy

  3. Of these, the greenhouse gas released in the largest quantity by human activity is

    1. a) methane
    2. b) nitrous oxide
    3. c) ozone
    4. d) carbon dioxide

  4. The equator receives more solar energy per square metre than the poles because

    1. a) it is closer to the Sun
    2. b) the Sun is hotter there
    3. c) there is less atmosphere
    4. d) sunlight strikes it more directly, spreading over less area

  5. Energy leaves Earth almost entirely as

    1. a) convection into space
    2. b) conduction through the atmosphere
    3. c) infrared radiation into space
    4. d) visible light

  6. The organelle that controls a cell's activities and holds its DNA is the

    1. a) nucleus
    2. b) mitochondrion
    3. c) vacuole
    4. d) ribosome

  7. Ocean currents affect climate mainly by

    1. a) moving thermal energy from the equator towards the poles
    2. b) changing the amount of sunlight received
    3. c) creating greenhouse gases
    4. d) raising sea level

  8. Osmosis is the diffusion of

    1. a) any substance through a cell wall
    2. b) salt across a membrane
    3. c) water across a selectively permeable membrane
    4. d) gases only

  9. The basic unit of life is the

    1. a) cell
    2. b) molecule
    3. c) tissue
    4. d) organ

  10. Active transport differs from diffusion in that it

    1. a) moves substances against a concentration gradient and uses ATP
    2. b) only moves water
    3. c) is faster
    4. d) needs no membrane

Answer key · Mixed review · Cells and global systems

Science 10 · maddyhelps.com

  1. b) mitochondrion — Mitochondria carry out the later stages of cellular respiration. Chloroplasts do photosynthesis and are found only in plants and algae — plant cells have both.
  2. c) the products of each are the reactants of the other — Matter cycles round the pair indefinitely; energy passes through once, entering as light and leaving as heat. That asymmetry is the key idea of the whole unit.
  3. d) carbon dioxide — Methane traps more heat per molecule, but far less of it is released. Quantity and potency are separate questions, and a good answer keeps them apart.
  4. d) sunlight strikes it more directly, spreading over less area — The curvature of Earth means polar sunlight arrives at a shallow angle and spreads over a larger area, and passes through more atmosphere on the way. The distance difference is negligible.
  5. c) infrared radiation into space — Space is a vacuum, so only radiation can carry energy away. Earth is far cooler than the Sun, so it radiates in the infrared rather than in visible light — and that is exactly the band greenhouse gases absorb.
  6. a) nucleus — Mitochondria release energy, ribosomes build proteins, and vacuoles store things. Prokaryotes such as bacteria have DNA but no nucleus to keep it in.
  7. a) moving thermal energy from the equator towards the poles — The oceans and the atmosphere together redistribute the energy imbalance between equator and poles. It is why western Europe is far milder than its latitude alone would suggest.
  8. c) water across a selectively permeable membrane — Water moves towards the more concentrated solution — that is, towards where there is proportionally less water. It is diffusion with a specific substance named.
  9. a) cell — All living things are made of one or more cells, all cells come from existing cells, and the cell is the smallest thing that carries out all the functions of life. That is the cell theory in one sentence.
  10. a) moves substances against a concentration gradient and uses ATP — Diffusion can only even things out. Concentrating a substance where it is already plentiful is uphill, so it has to be paid for with energy.