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 stays near 2 after day 28, since vaccine antibodies already cover the antigen
   • The level reaches 70 within 7 days, above the first peak of 6, since memory cells formed
   • The rise after day 28 is slower than after day 0, since the vaccine used up the antibodies
   • The rise after day 28 matches the rise after day 0, since each exposure starts from nothing
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 fast response to microbe P only, since its antigen matches the memory cells
   • A slow response to both microbes, since each exposure starts from nothing
   • 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?

   • Skin and mucus start after 1 day, and antibodies start after 3 days the first time
   • Antibodies start after 10 days on each exposure, so specific defenses cannot speed up
   • Antibodies start first, and phagocytes start after 10 days
   • Phagocytes start after 1 day, and antibodies start sooner on a repeat exposure
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 slow, low rise like a first exposure, since the antibodies do not fit square tips
   • A fast, high rise like a second exposure, because memory cells' antibodies fit any tip
   • 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, Skin and mucus are barriers at the body surface. 2, Antibodies are first-line defenses that act within minutes. 3, Inflammation, fever and phagocytes make up the second line. 4, Memory cells let a second response start sooner.

7. 6.

   Milo reviews a classmate's notebook on the lines of defense. Exactly one line is wrong. Which line, and why?

   • Line 1, because skin and mucus are second-line defenses that act after the antibodies
   • Line 3, because phagocytes and inflammation are part of the first line, not the second
   • Line 2, because antibodies are specific defenses that take days the first time
   • Line 4, because memory cells make a second response slower than the first one

8. 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.

9. 7.

   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 3, because a vaccine cannot lead to memory cells
   • Line 2, because the vaccine supplies the antibodies, not the B cells
   • Line 4, because the body makes its own antibodies after a vaccine

10. 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.

11. 8.

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

12. Two communities card (model data)

    community	people	immune people
    A	400	200
    B	400	360

13. 9.

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

    • Community A is better protected, since 200 immune people is a smaller number to protect
    • Community B is 90 percent immune, so a microbe meets fewer people it can spread to
    • 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

14. 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

15. 10.

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

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