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Grade 7 Science — Life processes in animals

Follow food through the alimentary canal and say what each part does, tell breathing from respiration, and match an animal to the way it takes in oxygen.

Name: ________________________

Before you start

The parts of the human respiratory system, from the nostrils down.

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  1. 1. Nostrils
  2. 2. Windpipe
  3. 3. Lung
  4. 4. Rib cage
  5. 5. Diaphragm

Air comes in at the nostrils, down the windpipe, and into branches that end in tiny balloon-like sacs called alveoli inside the lungs. The rib cage guards the lungs; the dome-shaped diaphragm below them does the pulling.

  1. 1.What is the difference between breathing and respiration?

    • a) Breathing happens in the lungs; respiration happens in the nose
    • b) Breathing is what animals do; respiration is what plants do
    • c) Breathing is a physical process moving air in and out; respiration is a chemical process using oxygen to release energy from food
    • d) They are two words for the same process

  2. 2.Match each digestive secretion to what it does.

    • Saliva
    • Bile from the liver
    • Pancreatic juice
    • Mucus
    • protects the stomach lining from the acid
    • breaks starch down into sugar
    • breaks fats into tiny droplets and neutralises acid
    • breaks down carbohydrates, proteins and fats

  3. 3.Put the parts of the alimentary canal in the order food passes through them, starting at the mouth.

    • Anus
    • Small intestine
    • Large intestine
    • Stomach
    • Mouth
    • Oesophagus
    • Rectum

  4. 4.Respiration uses oxygen to break down glucose. What comes out of it?

    • a) Glucose and energy, with nothing given off
    • b) Carbon dioxide, water and energy
    • c) Oxygen, water and starch
    • d) Carbon dioxide and starch

  5. 5.What does the acid in the stomach do, besides helping to break down proteins?

    • a) It absorbs nutrients into the blood
    • b) It turns starch into sugar
    • c) It stores the food until the intestine is ready
    • d) It kills many harmful bacteria

  6. 6.Inhaled air is nearly 21 per cent oxygen; exhaled air is nearly 16 per cent oxygen. How many percentage points of oxygen were taken from the air? Answer with a number.

  7. 7.Sort each animal by the part of its body that takes in oxygen.

    Groups: Breathes with lungs · Breathes with gills · Breathes through moist skin

    • Earthworm
    • Fish
    • Tadpole
    • Snake
    • Lion

  8. 8.A cow brings partially digested grass back up to its mouth and chews it thoroughly. What is that process called?

Answer key — Grade 7 Science — Life processes in animals

  1. 1. c) Breathing is a physical process moving air in and out; respiration is a chemical process using oxygen to release energy from food
  2. 2. Saliva → breaks starch down into sugar; Bile from the liver → breaks fats into tiny droplets and neutralises acid; Pancreatic juice → breaks down carbohydrates, proteins and fats; Mucus → protects the stomach lining from the acid
  3. 3. 1. Mouth 2. Oesophagus 3. Stomach 4. Small intestine 5. Large intestine 6. Rectum 7. Anus
  4. 4. b) Carbon dioxide, water and energy
  5. 5. d) It kills many harmful bacteria
  6. 6. 5
  7. 7. Lion → Breathes with lungs; Snake → Breathes with lungs; Fish → Breathes with gills; Tadpole → Breathes with gills; Earthworm → Breathes through moist skin
  8. 8. rumination