9th grade Viruses compared with cells, and how viruses spread worksheet

Viruses compared with cells, and how viruses spread

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   Ari compares a bacterium with a virus in a model drawing. Letter B points to the protein layer around the virus's genetic material. What is B called?

   • A ribosome, a structure that builds proteins
   • A cell wall, as on the bacterium
   • The envelope, a membrane around the coat
   • The capsid, a coat made of protein
2. 2.

   Model drawing, not to scale: an animal cell cutaway beside an enveloped virus. Bo studies a model drawing of an enveloped virus beside a host cell. Letter C points to the outer layer, made from host-cell membrane. What is C called?

   • The envelope, a layer of host-cell membrane
   • The nucleus, which holds the viral DNA
   • The plasma membrane, which the virus makes itself
   • The capsid, the coat made of protein
3. 3.

   Model drawing, not to scale: a plant cell cutaway beside a virus. Esme reads a model drawing of a virus beside a plant cell. Letter A points to the part with the instructions for making new virus particles. What is A?

   • A ribosome, which reads the instructions
   • The genetic material, which is DNA or RNA
   • The capsid, which holds a plan for each protein
   • The nucleus, which holds the viral DNA
5. 4.

   Kira uses the Venn diagram to place a fact about copying. Which sentence agrees with the diagram?

   • A virus copies itself in a host cell, so this fact is in the cell circle
   • A virus copies itself only in a host cell, so this fact is in the virus circle
   • A virus divides in two the way a bacterium does, so this fact is in the overlap
   • A virus copies itself on its own, so this fact is in the overlap with cells
6. 5.

   Luz checks the Venn diagram. Which feature do a virus and a cell both have?

   Use the picture in question 4.

   • A plasma membrane of its own
   • A protein coat called a capsid
   • Ribosomes that build proteins
   • A nucleic acid as genetic material

7. Read this first

   Use this

   Word card (model). The word to define is host cell. Examples named on the card: a bacterium for a bacteriophage; a plant cell for a plant virus. Not to scale.

8. 6.

   Milo learns the term host cell for viruses. Which meaning is right?

   • A cell that a virus cannot attach to because it lacks a receptor
   • A small cell made of genetic material wrapped in a protein coat
   • A cell that a virus enters and uses to make new virus particles
   • A cell in which a virus copies itself on its own, with no help

9. Use this

   Word card (model). The word to define is virion. Examples named on the card: one virus particle sitting outside any host cell. Not to scale.

10. 7.

    Pia meets the word virion on a word card. Which meaning is right?

    • A small cell with a protein coat and genetic material
    • A single virus particle outside a host cell
    • The protein coat of a virus, with nothing inside
    • A virus that has copied itself many times

11. Widths table (real data, from OpenStax Biology 2e; 1 µm = 1,000 nm)

    particle	width in nm	width in µm
    most virions	20 to 250	0.02 to 0.25
    prokaryotic cell	100 to 5,000	0.1 to 5.0
    eukaryotic cell	10,000 to 100,000	10 to 100

12. 8.

    Ren reads the table of widths. What is the width range of most virions?

    • 20 to 250 nm
    • 10 to 100 µm
    • 20 to 250 µm
    • 0.1 to 5.0 µm
13. 9.

    1 µm = 1,000 nm. Tala measures three model particles, P, Q and R. Using the table, which one is most likely a virion?

    • Q, because 3 µm is inside the virion range
    • P, because 80 nm is inside the virion range
    • R, because a virus is larger than a cell
    • P and Q, because both are smaller than a eukaryotic cell

14. Widths table (real data, from OpenStax Biology 2e; 1 µm = 1,000 nm)

    particle	width in nm	width in µm
    most virions	20 to 250	0.02 to 0.25
    prokaryotic cell	100 to 5,000	0.1 to 5.0
    eukaryotic cell	10,000 to 100,000	10 to 100

15. 10.

    Zee compares the widest virion in the table with the narrowest eukaryotic cell. Which statement agrees with the table?

    • The widest prokaryotic cell, 5.0 µm, is narrower than the widest virion, 250 nm
    • A virion and a eukaryotic cell overlap in width, between 20 and 100
    • A virion is wider than a eukaryotic cell, because 250 is more than 100
    • The widest virion in the table, 0.25 µm, is narrower than the narrowest eukaryotic cell, 10 µm