Cell structures and specialised cells
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The teaching part (2 min) is free to watch. A free account opens the whole lecture: 3 worked examples, 5 practice questions, 2 real past-paper questions with the answers explained, the mistakes that lose marks, the full-marks tip, a one-card summary and a quick quiz.
What this lecture covers
- The building blocks
- An animal cell
- What each part does
- A plant cell
- The plant extras
- A bacterial cell
- Compare the three
- Specialised cells
- Six specialised cells
Read the transcript of the teaching part
Last time
Before we start: last time, in Magnification and size, you learned these points. Here they are again on one card. Keep them in mind, because today builds on them.
The building blocks
Every living thing is made of cells, from one cell in a bacterium to about thirty trillion in you. Today: the parts of animal, plant and bacterial cells, what each part does, and how cells are specialised for one job.
An animal cell
Here is an animal cell, such as a cheek cell. It has a cell membrane, cytoplasm, a nucleus, mitochondria and ribosomes.
What each part does
The nucleus contains the genetic material, the chromosomes, which control the activities of the cell. The cell membrane controls what enters and leaves the cell. The cytoplasm is where most chemical reactions happen. Mitochondria are where aerobic respiration releases energy. Ribosomes make proteins.
A plant cell
A plant cell, such as a palisade cell, has all the animal parts and three more. A cellulose cell wall, chloroplasts, and a large permanent vacuole full of cell sap.
The plant extras
The cell wall is made of cellulose. It is strong and stops the cell bursting when it takes in water. Chloroplasts contain chlorophyll, which absorbs light energy for photosynthesis. The vacuole contains cell sap. When it is full, it presses outwards and keeps the cell firm.
A bacterial cell
Now a bacterial cell. It has a cell wall, a membrane, cytoplasm and ribosomes, but no nucleus. Its DNA is a circular chromosome, and it may have extra small rings called plasmids.
Compare the three
Here is the comparison the examiner wants. Only plant cells have chloroplasts and a large vacuole. Only the bacterial cell has no nucleus and has plasmids.
Specialised cells
In a multicellular organism, cells are specialised: their shape and parts suit one function. Similar cells working together form a tissue, tissues form an organ, and organs form an organ system.
Six specialised cells
Learn these six. Each has one feature that fits its job. The examiner often asks for the feature and how it helps.
How often it comes up
How often Cambridge has asked each part, counted by ExamYard from every past paper in its question bank: Functions of cell structures · Plant, animal and bacterial cells · Specialised cells.
The whole chapter: Organisation of the Organism, Cells.
Chapter 2: Organisation of the organism
- Cell structures and specialised cells 5 min
- Magnification and size 5 min
Also for IGCSE Biology 0610
Which topics come up most in IGCSE Biology 0610 past papers, counted from every paper since 2004.