How the body defends itself: immunity, vaccines and antibiotics

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   Ari reads a graph for a vaccine at day 0 and a microbe with the same antigen at day 28. Which statement combines what the graph shows with why?

   • The level reaches 70 within 7 days, above the first peak of 6, since memory cells formed
   • The level stays near 2 after day 28, since vaccine antibodies already cover the antigen
   • The rise after day 28 matches the rise after day 0, since each exposure starts from nothing
   • The rise after day 28 is slower than after day 0, since the vaccine used up the antibodies
2. 2.

   Microbe card (model data), 2 rows. Columns: microbe, antigen on its surface. P, X. Q, Y. Bo reads a microbe card. A vaccine with antigen X was given earlier, and antigen Y is not similar to X. Which statement fits both microbes?

   • A slow response to both microbes, since each exposure starts from nothing
   • A fast response to microbe P only, since its antigen matches the memory cells
   • A fast response to microbe Q only, since a new antigen wakes the memory cells
   • A fast response to both microbes, since memory cells match any antigen
3. 3.

   Esme reads a defense timing card. Which statement combines the lines of defense with the timing on the card?

   • Antibodies start first, and phagocytes start after 10 days
   • Skin and mucus start after 1 day, and antibodies start after 3 days the first time
   • Phagocytes start after 1 day, and antibodies start sooner on a repeat exposure
   • Antibodies start after 10 days on each exposure, so specific defenses cannot speed up
4. 4.

   Jun reads a shape card. A microbe's surface changes from antigen X to a new antigen Z. Which prediction fits the next response?

   • A fast, high rise like a second exposure, because memory cells' antibodies fit any tip
   • A slow, low rise like a first exposure, since the antibodies do not fit square tips
   • A fast, high rise, because the microbe is still the same kind of microbe as before
   • No rise, because the first response cleared that microbe from the body for good
5. 5.

   Kira reads a graph for one vaccine dose at day 0. In the model, a second dose is given at day 28. Which prediction fits the response after it?

   • The same as after dose 1, because memory cells reset after each dose of the vaccine
   • Lower than after dose 1, because the first dose used up the antigen in the vaccine
   • Higher than after dose 1, because dose 2 delivers ready-made antibodies
   • Higher and faster than after dose 1, because dose 2 acts like a second exposure

6. Read this first

   Use this

   Notebook (model data), 4 rows. Columns: line, what it says. 1, A vaccine contains an antigen from a microbe. 2, After a vaccine, the body's own B cells make antibodies. 3, Memory cells can make a later response faster. 4, A vaccine gives the person ready-made antibodies.

7. 6.

   Noah reviews a classmate's notebook on vaccines. Exactly one line is wrong. Which line, and why?

   • Line 1, because a vaccine contains no antigen
   • Line 2, because the vaccine supplies the antibodies, not the B cells
   • Line 3, because a vaccine cannot lead to memory cells
   • Line 4, because the body makes its own antibodies after a vaccine

8. Use this

   Notebook (model data), 4 rows. Columns: line, what it says. 1, Antibiotics treat certain infections caused by bacteria. 2, Antibiotics work on the viruses that cause a cold or the flu. 3, Bacteria that survive an antibiotic can multiply and spread their resistance. 4, A vaccine prepares memory cells, which is different from what an antibiotic does.

9. 7.

   Pia reviews a classmate's notebook on antibiotics. Exactly one line is wrong. Which line, and why?

   • Line 2, because antibiotics do not work on viruses
   • Line 3, because resistance is a trait of people, not of bacteria
   • Line 4, because a vaccine and an antibiotic do the same job
   • Line 1, because antibiotics treat any kind of germ
10. 8.

    Ren reads a graph of antibody level after exposures at day 0 and day 28. Which statement does the graph support?

    • The second peak, 100, was 10 times the first peak, 10, but came later after its exposure
    • The second peak, 100, was 90 times the first peak, 10, and came sooner after its exposure
    • The second peak, 100, matched the first peak, and came sooner after its exposure
    • The second peak, 100, was 10 times the first peak, 10, and came sooner after its exposure

11. Two communities card (model data)

    community	people	immune people
    A	400	200
    B	400	360

12. 9.

    Tala reads a card on two communities. Which statement does the card support?

    • Community B is 90 percent immune, so a microbe meets fewer people it can spread to
    • Community A is better protected, since 200 immune people is a smaller number to protect
    • In both communities each immune person is protected alone, so spread is equal
    • Community B is fully protected, so each person in it is safe from the microbe

13. Bacteria count card (model data)

    step	bacteria	bacteria with the resistance trait
    before the antibiotic	1,000	10
    just after the antibiotic	10	10
    after regrowth	640	640

14. 10.

    Zee reads a count card for bacteria and one antibiotic. Which statement does the card support?

    • The person's own cells became resistant to the antibiotic, so 640 bacteria grew back
    • The 10 bacteria that remained had the trait before the antibiotic and then multiplied
    • The antibiotic gave the resistance trait to the 10 bacteria that remained in the sample
    • The antibiotic cleared the viruses too, so just the bacteria with the trait were left