Raven spreads a printed table beside the sliced celery. "This is from the college text. Every row is a cell part."
Rocket reads the headings. "Cell component. Function. Present in animal cells? Present in plant cells? Yes and no all the way down."
"What do you notice about the rows that say no for animals and yes for plants?" Raven asks.
"Cell wall. Chloroplasts." Rocket runs his finger along. "And one row goes the other way. Lysosomes, yes for animals, no for plants."
Nova hovers over the celery slice, its dots still blue. "Which row explains those dots standing up straight?"
"Cell wall," Rocket says. "Protection, support and shape." Raven smiles. "Now read every row."
The open text Concepts of Biology has a table of cell components, their functions, and whether animal and plant cells have them.
Here are its rows for the parts you have met, shortened. Read the whole table before answering.
Most rows say yes for both. The differences are the point: plants have a wall and chloroplasts, and animals have lysosomes.
| Cell component | Function, in short | Animal cells? | Plant cells? |
|---|---|---|---|
| Plasma membrane | Separates cell from outside; controls passage of water, oxygen, wastes and other substances | Yes | Yes |
| Cytoplasm | Provides structure; medium in which organelles are found | Yes | Yes |
| Nucleus | Houses DNA; directs the making of ribosomes and proteins | Yes | Yes |
| Ribosomes | Protein synthesis | Yes | Yes |
| Mitochondria | Energy production from food (cellular respiration) | Yes | Yes |
| Lysosomes | Digestion of large molecules; recycling worn-out organelles | Yes | No |
| Cell wall | Protection, structural support and maintenance of cell shape; mainly cellulose in plants | No | Yes |
| Chloroplasts | Photosynthesis | No | Yes |
| Vesicles and vacuoles | Storage and transport | Yes | Yes |
| Statement | True or false? |
|---|---|
| Plant cells have mitochondria. | ? |
| Animal cells have a cell wall. | ? |
| Both animal and plant cells have a nucleus. | ? |
| Plant cells have lysosomes. | ? |
Careful reading. Tomorrow you find cell walls and chloroplasts all over your kitchen, and review the week.