If the teeth are not cleaned regularly, they become covered with a sticky yellowish layer W of food particles and bacteria. Since layer W covers the teeth, the alkaline liquid X secreted by glands Y inside the mouth cannot reach the teeth surface to neutralise the acid formed by the action of organisms Z on sugary food, and hence tooth decay sets in.
  1. What is W known as?
  2. What is (i) X, and (ii) Y?
  3. What are organisms Z?
  4. State one way of removing layer W from the teeth.
Download our app for free and get startedPlay store
  1. W is the dental plaque.
  2.  
  1. X refers to the saliva.
  2. Y refers to the salivary glands.
  1. Organisms Z are bacteria.
  2. Layer of W, i.e. dental plaque, can be removed by regular brushing of teeth.
art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    1. List the three events that accur during the process of photosynthesis. Explain the role of stomata in this process.
    2. Describe an experiment to show that ''sunlight is essential for photosynthesis.''
    View Solution
  • 2
    Explain the process of digestion of food in mouth, stomach and small intestine in human body.
    View Solution
  • 3
    Differentiate between an artery and a vein.
    View Solution
  • 4
    1. Draw a diagram of excretory system in human beings and label on it: Aorta, Vena cava, Urinary bladder, Urethra.
    2. List two vital functions of the kidney.
    View Solution
  • 5
    Describe the flow of blood through the heart of human beings.
    View Solution
  • 6
    How are fats digested in our bodies? Where does this process take place?
    View Solution
  • 7
    Describe double circulation in human beings. Why is it necessary?
    View Solution
  • 8
    Explain the three pathways of breakdown in living organisms.
    View Solution
  • 9
    Plants absorb water from the soil. How does this water reach to the top of the tree? Explain in detail.
    View Solution
  • 10
    1. Draw a diagram of human alimentary canal and label on it: Oesophagus, Gallbladder, Liver and Pancreas.
    2. Explain the statement, ‘Bile does not contain any enzyme but it is essential for digestion.’
    View Solution