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
- A prokaryote, because it has no nucleus or membrane-bound organelles
- A plant cell, because it has a cell wall around its membrane
- An animal cell, because it uses a flagellum to move about
It has no cell wall. Esme compares card U with a bacterium. Which parts does cell U share with a bacterium?
- Plasma membrane, cytoplasm and ribosomes, since bacteria lack DNA
- Nucleus, ribosomes and DNA, since a bacterium has a nucleus too
- Plasma membrane, cytoplasm and DNA, since bacteria lack ribosomes
- Plasma membrane, cytoplasm, ribosomes and DNA
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 in a tiny nucleus, because a bacterium is a tiny animal cell
- It has DNA, kept in a nucleoid
- 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?
- Nucleoids, found in the bacterium but not the animal cell
- Ribosomes, found in both the bacterium and the animal cell
- Mitochondria, found in both the bacterium and the animal cell
- Ribosomes, found in the animal cell but not the bacterium
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?
- 20 times
- 2 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
- 40 bacteria
- 18 bacteria
- 22 bacteria
Size ranges and three model cells (real data and model data)
item width in µm prokaryotic range (real data) 0.1 to 5.0 eukaryotic range (real data) 10 to 100 cell 1 (model data) 0.8 cell 2 (model data) 40 cell 3 (model data) 3 Judging by size alone, which of Noah's model cells could be prokaryotes?
- Cell 2 alone
- Cells 1 and 2
- Cells 2 and 3
- Cells 1 and 3
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?
- 0.24 per µm
- 10 per µm
- 1.2 per µm
- 0.83 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 rose, because the surface area grew from 600 to 2400
- The ratio stayed the same, because the shape is still a cube
- The larger cell is better, because 2400 is far more membrane than 600