How the body defends itself: immunity, vaccines and antibiotics

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Use this

   Map of the body's defenses (model, not to scale). Arrows, each marked with what it carries: microbe to skin and mucus, meets a barrier; skin and mucus to inflammation and fever, a microbe gets past; inflammation and fever to phagocytes, calls in; phagocytes to T cells, shows antigen pieces; T cells to B cells, sends an activation signal; B cells to antibodies, make; B cells to memory cells, some become.

2. 1.

   Ari follows a microbe on the map of the body's defenses. It gets past skin and mucus. Which defense does it meet next?

   • Memory cells, which stay from an earlier response
   • Skin and mucus, the barrier at the surface
   • B cells, which begin making antibodies
   • Inflammation and fever, which call in phagocytes
3. 2.

   Bo follows the map after phagocytes engulf a microbe. They show antigen pieces to the next cells. Which cells are next, and what do they do?

   • Antibodies, which bind the antigen pieces
   • B cells, which make antibodies at once
   • Memory cells, which make antibodies at once
   • T cells, which signal B cells to act

4. Use this

   Map of how a vaccine prepares the body (model, not to scale). Arrows, each marked with what it carries: vaccine to phagocytes, antigen pieces; phagocytes to T cells, shows antigen pieces; T cells to B cells, sends an activation signal; B cells to antibodies, make; B cells to memory cells, some become.

5. 3.

   Esme follows the map of how a vaccine prepares the body. After B cells are activated, which two products follow?

   • Phagocytes, and antigen pieces
   • Antibodies alone, with no cells left for next time
   • Antibodies, and memory cells that stay
   • Antibodies, and phagocytes that stay for next time
6. 4.

   Jun reads the three lines card and sorts a case. Tears wash microbes away from the surface of the eye. Which line is this?

   • Not a defense, because tears just keep the eye wet
   • Second line, the response inside the body
   • First line, the barriers at the body surface
   • Specific defenses, which are ready before any microbe arrives

7. Use this

   Two types of immunity card (CDC facts), 2 rows. Columns: type, where the antibodies come from, timing. active, the person's own B cells, after an infection or a vaccine, takes longer to develop and lasts longer. passive, another person or an animal, protects at once and fades within weeks or months.

8. 5.

   Luz reads the card on two types of immunity. A vaccine's antigen leads a person's own B cells to make antibodies and memory cells. Which type is this?

   • Active, because the protection starts at once
   • Passive, because the protection lasts for years
   • Passive, because the vaccine supplies the antibodies
   • Active, because the person's own cells make the antibodies
9. 6.

   Milo reads a graph of antibody level after a vaccine with antigen X. At day 35 a microbe with antigen X arrives. Which prediction fits?

   • Antibodies stay low, because the vaccine supplied antibodies that are used up
   • Antibodies rise quickly and high, because memory cells formed after the vaccine
   • Antibodies rise slowly again, because the vaccine left no memory
   • Antibodies rise quickly and high, because vaccine antibodies fit any microbe
10. 7.

    Noah reads a graph of antibody level against antigen X. At day 28 a microbe with a very different antigen, Y, arrives. Which prediction fits?

    • A fast rise, because the first response sped up each later response
    • A slow rise like the first, because memory cells are for antigen X
    • No rise, because antibodies against antigen X already fit antigen Y
    • A fast, high rise, because memory cells recognize any antigen

11. Use this

    Two types of immunity card (CDC facts), 2 rows. Columns: type, where the antibodies come from, timing. active, the person's own B cells, after an infection or a vaccine, takes longer to develop and lasts longer. passive, another person or an animal, protects at once and fades within weeks or months.

12. 8.

    Pia reads the card on two types of immunity. A person has passive protection that began at day 0. Which prediction fits for day 365?

    • The protection is stronger, because the antibodies multiply in the person
    • The protection has faded, because the antibodies came from another source
    • The protection has not begun, because passive immunity takes weeks to start
    • The protection is still strong, because passive immunity outlasts active immunity

13. Antibody response card (model data)

    exposure	antibodies first rise (days after the exposure)	peak level (arbitrary units)
    first	12	30
    second	4	300

14. 9.

    Ren reads an antibody response card. How many days sooner did antibodies first rise after the second exposure than after the first?

    • 12 days
    • 8 days
    • 4 days
    • 16 days

15. Vaccine facts card (CDC and WHO facts)

    source	fact
    CDC	CDC monitors the safety of licensed vaccines through 4 systems that work together
    WHO	no single vaccine gives 100 percent protection

16. 10.

    Tala reads a vaccine facts card from CDC and WHO. Which statement do the numbers on the card support?

    • Licensed vaccines are watched by 1 system, and each gives 100 percent protection
    • Safety checks end once a vaccine is licensed, so 0 systems watch it
    • Licensed vaccines are watched by 4 systems, so each gives 100 percent protection
    • Licensed vaccines are watched by 4 systems, and none gives 100 percent protection