Viruses compared with cells, and how viruses spread
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
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?
- The envelope, a membrane around the coat
- A cell wall, as on the bacterium
- A ribosome, a structure that builds proteins
- The capsid, a coat made of protein
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?
- The capsid, which holds a plan for each protein
- A ribosome, which reads the instructions
- The genetic material, which is DNA or RNA
- The nucleus, which holds the viral DNA
Jun reads a Venn diagram that compares a virus with a cell. In which part is the word ribosomes written?
- In the cell circle only, so a virus has none
- Outside both circles, so neither has ribosomes
- In the overlap, so a virus has ribosomes too
- In the virus circle only, so cells have none
Luz checks the Venn diagram. Which feature do a virus and a cell both have?
Use the picture in question 3.
- Ribosomes that build proteins
- A protein coat called a capsid
- A nucleic acid as genetic material
- A plasma membrane of its own
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.
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 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
- A small cell made of genetic material wrapped in a protein coat
Use this
Word card (model). The word to define is bacteriophage. Examples named on the card: a phage with a head and a tail. Not to scale.
Noah meets the word bacteriophage on a word card. Which meaning is right?
- A virus that infects plant cells and animal cells
- A tiny bacterium that is covered by a protein coat
- A bacterium that makes copies of itself inside a virus
- A virus that infects bacteria as its host cells
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.
Pia meets the word virion on a word card. Which meaning is right?
- The protein coat of a virus, with nothing inside
- A virus that has copied itself many times
- A small cell with a protein coat and genetic material
- A single virus particle outside a host cell
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 Ren reads the table of widths. What is the width range of most virions?
- 20 to 250 nm
- 10 to 100 µm
- 0.1 to 5.0 µm
- 20 to 250 µm
1 µm = 1,000 nm. Tala measures three model particles, P, Q and R. Using the table, which one is most likely a virion?
- R, because a virus is larger than a cell
- Q, because 3 µm is inside the virion range
- P, because 80 nm is inside the virion range
- P and Q, because both are smaller than a eukaryotic cell
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 Zee compares the widest virion in the table with the narrowest eukaryotic cell. Which statement agrees with the table?
- The widest virion in the table, 0.25 µm, is narrower than the narrowest eukaryotic cell, 10 µm
- 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