How the body defends itself: immunity, vaccines and antibiotics

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   Ari reads a map of the body's defenses. Box X is the first line, a barrier at the body surface. What is box X?

   • Memory cells, cells kept after a response
   • Antibodies, proteins that match one antigen
   • Phagocytes, cells that engulf microbes
   • Skin and mucus, barriers at the body surface
2. 2.

   Esme reads the map of the body's defenses. Phagocytes show antigen pieces to box Z, which then signals B cells. What is box Z?

   • Memory cells, cells kept after a response
   • Antibodies, proteins that fit any microbe
   • T cells, cells that signal B cells
   • Skin and mucus, barriers at the body surface

3. Read this first

   Use this

   Map of how a vaccine prepares the body (model, not to scale).

4. 3.

   Jun reads a map of how a vaccine prepares the body. B cells make the proteins in the blank box. What belongs in the blank box?

   • Fever, a rise in body temperature
   • Antibodies, proteins that match an antigen
   • Phagocytes, cells that engulf microbes
   • Skin and mucus, barriers at the body surface
5. 4.

   Luz reads a map of how a vaccine prepares the body. Some B cells become the blank box, which stays after the response. What belongs there?

   • Antigen pieces, parts of a microbe
   • Antibodies, proteins that B cells make
   • Memory cells, cells that stay for next time
   • Phagocytes, cells that engulf microbes
6. 5.

   Two maps (model, not to scale) of the order in which defenses act on a new microbe. Milo compares two maps of the order in which defenses act on a new microbe. Which case shows the usual order?

   • Case P, because skin and mucus make the antibodies
   • Case P, because barriers act first and antibodies take days
   • Case Q, because antibodies are ready before any microbe arrives
   • Case Q, because specific defenses are the fastest

7. Use this

   Two maps (model data, not to scale) of antibody levels after a second exposure to the same microbe, once memory cells have formed.

8. 6.

   Noah compares two maps of a second exposure to the same microbe. Which case matches how memory cells change the response?

   • Case 2, because memory cells give a faster, higher response
   • Case 2, because a faster, higher response needs a new microbe
   • Case 1, because memory cells make the response slower
   • Case 1, because the response is the same each time
9. 7.

   Pia compares two maps of an antibody meeting an antigen with a triangle tip. Which case shows an antibody that can bind it?

   • Case 2, because any antibody can bind any antigen
   • Case 1, because its notch matches the antigen's shape
   • Case 1, because both parts are drawn at the same height
   • Case 2, because a round notch grips better

10. Antibiotic card (CDC facts)

    kind of germ	what CDC says about antibiotics
    bacteria	can treat certain infections caused by bacteria
    viruses	do not work on the viruses that cause a cold or the flu

11. 8.

    Ren reads an antibiotic card. According to the card, do antibiotics work on the viruses that cause a cold or the flu?

    • No, they do not work on viruses
    • Yes, they work on any kind of germ
    • Yes, on the cold but not on the flu
    • Yes, if they are taken for a longer time
12. 9.

    Tala reads a graph of antibody level after a first and a second exposure to one microbe. Which exposure gave the higher level at day 7?

    • Both lines are level
    • Neither line has risen
    • The first exposure
    • The second exposure

13. Vaccine card (CDC facts)

    vaccine form	what it contains	active ingredient
    whole microbe	a weakened or inactivated microbe	an antigen
    pieces	bits of the microbe's outside or genetic material	an antigen
    toxin	a bacterial toxin made harmless	an antigen

14. 10.

    Zee reads a vaccine card. According to the card, what is the active ingredient in each form of vaccine?

    • An antibiotic that removes the virus
    • An antigen from the microbe
    • Ready-made antibodies for the microbe
    • Memory cells grown for the person