Class 9 Science — The cell and what is inside it

Name the parts of a plant and an animal cell and say what each does, tell a prokaryotic cell from a eukaryotic one, and use osmosis to explain what happens to a cell in salty water.

Name: ________________________

Before you start

The parts of a cell, each one named.

1. The round body with a smaller body inside it — the nucleus
2. The rod with folded lines inside — a mitochondrion
3. The large clear space — the vacuole
4. The stack of folded sheets — the endoplasmic reticulum

The outline round the whole thing is the cell membrane. On a plant cell there would be a stiffer layer of cellulose outside it again, and green ovals of chloroplast among the organelles.

1.Sort each feature by the kind of cell it belongs to.
Groups: Prokaryotic cell · Eukaryotic cell
- Membrane-bound nucleus
- A typical width of 10 to 100 micrometres
- Membrane-bound organelles
- A typical width of 1 to 10 micrometres
- Genetic material in a bare nucleoid
2.A Rhoeo leaf peel is mounted in a strong sugar solution. Its cells lose water, yet the outline of each cell stays the same shape. What accounts for that?
- a) Plant cells cannot lose water through their membranes
- b) The chloroplasts stiffen and hold the cell out
- c) The rigid cell wall holds the outer shape while the membrane pulls inwards
- d) The vacuole refills from the sugar solution as fast as water leaves
3.What is a plant cell wall built mainly from?
- a) Starch
- b) Protein
- c) Cellulose
- d) Lipid
4.Which statement is part of the classical cell theory?
- a) New cells can form from non-living matter under the right conditions
- b) Cells are found in animals but not in plants
- c) New cells arise from cells that already exist
- d) The tissue, not the cell, is the basic unit of function
5.Who examined a thin slice of cork in 1665 and gave the little compartments he saw the name we still use? Give the surname.
6.A piece of potato is left in a 20 per cent salt solution for an hour. What happens to it, and why?
- a) It swells, because salt is drawn into the cells from the solution
- b) It shrinks, because salt is drawn out of the cells into the water
- c) Nothing changes, because the membrane blocks both water and salt
- d) It shrinks, because water leaves the cells for the more concentrated solution
7.Sort each structure by whether an animal cell has one too.
Groups: In a plant cell but not an animal cell · In both a plant and an animal cell
- Cell membrane
- Mitochondrion
- Cell wall
- Nucleus
- Chloroplast
- Large central vacuole
8.A parent cell divides by mitosis. What comes out of it?
- a) Two daughter cells with half the parent's chromosome number
- b) Four daughter cells with half the parent's chromosome number
- c) Two daughter cells with the parent's chromosome number, genetically identical to it
- d) Four daughter cells genetically identical to the parent

Answer key — Class 9 Science — The cell and what is inside it

1. Genetic material in a bare nucleoid → Prokaryotic cell; A typical width of 1 to 10 micrometres → Prokaryotic cell; Membrane-bound organelles → Eukaryotic cell; Membrane-bound nucleus → Eukaryotic cell; A typical width of 10 to 100 micrometres → Eukaryotic cell
2. c) The rigid cell wall holds the outer shape while the membrane pulls inwards
3. c) Cellulose
4. c) New cells arise from cells that already exist
5. Hooke
6. d) It shrinks, because water leaves the cells for the more concentrated solution
7. Cell wall → In a plant cell but not an animal cell; Chloroplast → In a plant cell but not an animal cell; Large central vacuole → In a plant cell but not an animal cell; Cell membrane → In both a plant and an animal cell; Nucleus → In both a plant and an animal cell; Mitochondrion → In both a plant and an animal cell
8. c) Two daughter cells with the parent's chromosome number, genetically identical to it