Prokaryotic and eukaryotic cells compared
Grade 9 Science Worksheet
Circle the best answer.
Read this first
Use this
Cell card X (model data, not to scale), from a pond-water sample. It has no nucleus and no other membrane-bound organelle.
Ari and a teacher read card X. What kind of cell is X, and why?
- A eukaryote, because ribosomes are found in eukaryotes
- An animal cell, because it uses a flagellum to move about
- A prokaryote, because it has no nucleus or membrane-bound organelles
- A plant cell, because it has a cell wall around its membrane
“(model data, not to scale),” Bo reads card Y, from a mushroom. What kind of cell is Y, and why?
- A prokaryote, because it has ribosomes and a plasma membrane
- A eukaryote, because it has a nucleus, and a wall does not decide
- A plant cell, because a cell wall means a plant cell
- A prokaryote, because a cell wall is a feature of bacteria
Use this
Two cell cutaways side by side (model drawing, not to scale) above a Venn diagram. Left cutaway: a prokaryotic cell. Right cutaway: a eukaryotic (animal) cell. Venn diagram, left circle, prokaryotic cell only: DNA in a nucleoid; no membrane-bound organelles. Right circle, eukaryotic cell only: DNA inside a nucleus; membrane-bound organelles. Overlap, both cells: plasma membrane; cytoplasm; ribosomes; DNA.
Kira reads the Venn diagram. Which statement about building proteins is right?
- Prokaryotic cells lack ribosomes, so they cannot build proteins
- Prokaryotic cells are tiny animal cells, so they build proteins in a nucleus
- Eukaryotic cells have ribosomes, and prokaryotic cells use the nucleoid instead
- Both kinds of cell use their ribosomes to build proteins
Luz uses the Venn diagram to decide what is true of the DNA in a bacterium. Which statement is right?
- It has DNA, kept in a nucleoid
- It has DNA in a tiny nucleus, because a bacterium is a tiny animal cell
- It has DNA, kept inside its ribosomes
- It has no DNA, because DNA needs a nucleus to be kept in
model drawing, not to scale. Tala labels two cutaways. Letters B and F point to the same kind of part: small dots that build proteins. What are they, and where are they found?
- Ribosomes, found in the animal cell but not the bacterium
- Ribosomes, found in both the bacterium and the animal cell
- Mitochondria, found in both the bacterium and the animal cell
- Nucleoids, found in the bacterium but not the animal cell
Cell diameters (real data, from OpenStax Biology)
kind of cell smallest diameter in µm largest diameter in µm prokaryotic cell 0.1 5.0 eukaryotic cell 10 100 Esme uses the table. How many times wider is the smallest eukaryotic cell than the largest prokaryotic cell?
- 2 times
- 20 times
- 50 times
- 5 times
Two model cells (model data, widths inside the real ranges)
cell width in µm model bacterium 2 model eukaryotic cell 20 Ren lines up model bacteria end to end across the model eukaryotic cell. How many bacteria fit across its width?
- 10 bacteria
- 22 bacteria
- 18 bacteria
- 40 bacteria
Pia compares model cells. A cube cell has surface area 6 × side × side and volume side × side × side. Which cell has more membrane for each unit of volume?
- Neither cell, because both cells are cubes
- The 2 µm cell, with a ratio of 3 against 1.5
- The 4 µm cell, because its volume of 64 holds more materials
- The 4 µm cell, because 96 is more surface area than 24
Model cube cell (model data)
quantity value side in µm 5 surface area formula 6 × side × side volume formula side × side × side Zee uses the formulas. What is the surface area-to-volume ratio of this model cube cell?
- 0.83 per µm
- 10 per µm
- 0.24 per µm
- 1.2 per µm
A model cell grows from a 10 µm cube to a 20 µm cube. Jun says the larger cell exchanges materials better. What does the table show?
- The ratio fell from 0.6 to 0.3, so the larger cell has less membrane per unit of volume
- The ratio stayed the same, because the shape is still a cube
- The ratio rose, because the surface area grew from 600 to 2400
- The larger cell is better, because 2400 is far more membrane than 600