AQA Biology 4.1.1.2
Animal and plant cells
Five parts in every animal cell; plant cells add up to three more. Place each part, then work out how big a cell really is from a drawing.
Triple Science · Foundation tier
Start here
Lettuce and carrots.
Leave lettuce out without water and it goes limp. A fresh raw carrot snaps cleanly in two. Your own skin does neither.
If you had to guess, do plant cells have something stiff around them that ours don’t?
Side by side
Same five parts, plus three in plant cells.
Tap each part to find it in the cells and see what it does. Notice which cell has it.
Nucleus (both cells): Contains genetic material, which controls the activities of the cell.
Required practical 1 · observe and label
What you see down a light microscope.
With a light microscope you can see the nucleus, cytoplasm, cell membrane, cell wall, vacuole and chloroplasts. Ribosomes are too small to see. Iodine solution stains onion cells: the nucleus shows yellow-brown. Methylene blue stains cheek cells: the nucleus shows blue. The full method, focusing and drawing rules are in the Microscopy lesson.
Estimate: about how much of this plant cell does the vacuole fill?
Equation · magnification
Convert first: both sizes must be in the same unit. 1 mm = 1000 µm, so mm × 1000 gives µm, and µm ÷ 1000 gives mm. Magnification has no unit: write it as ×400, for example. Tap the quantity you want to find.
Equation
Magnification
Side by side: multiply.
One over the other: divide.
Tap the quantity you want to find.
Written out
magnification = size of image ÷ size of real object
- I
- size of image
- µm
- M
- magnification
- no unit
- A
- size of real object
- µm
Think again · are all plant cells green?
“Every plant cell has chloroplasts.”
Your call
ChooseA student looks at a cell from a plant’s root. Which part will not be there?
Sort
Both, or plant cells only?
Place each part.
Tap a card, then tap the box it belongs in. Tap a placed card to take it back.
Command words in this lesson
- Name
- The part, using its proper name.
- Compare
- What both have, then what only plant cells have.
- Calculate
- Convert to one unit, then image ÷ real.
Key fact
Animal cells have a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. Plant cells have these too, plus a cellulose cell wall, a permanent vacuole and often chloroplasts.
Key note · AQA 4.1.1.2
Animal and plant cells
- Animal cells: nucleus, cytoplasm, cell membrane, mitochondria, ribosomes.
- Plant cells: all of those, plus a cellulose cell wall, a permanent vacuole of cell sap and, often, chloroplasts.
- Nucleus: genetic material. Membrane: controls what goes in and out. Mitochondria: aerobic respiration. Ribosomes: protein synthesis.
- Iodine on onion cells: nucleus yellow-brown. Methylene blue on cheek cells: nucleus blue.
- Magnification = size of image ÷ size of real object. Convert to the same unit first: 1 mm = 1000 µm.
Photograph this card. Tomorrow, cover it and say each line first.
Previous and next
Connects to
Ask MrBadmus
Not sure when to convert mm to µm?
Cell drawings are schematic and not to scale.