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Animal and plant cells are eukaryotic: their genetic material is enclosed in a nucleus. Both have cytoplasm, a cell membrane, mitochondria and ribosomes. Plant cells also typically have a cellulose cell wall, a permanent vacuole and, in photosynthetic tissues, chloroplasts. Bacteria are prokaryotic: their DNA is not enclosed in a nucleus, and they may contain plasmids. Do not add mitochondria or chloroplasts to a bacterial diagram.
Video by Cognito. The video’s own board label is retained; follow the specification reference and scope notes on this lesson for assessed content.
Viewing focus: Compare animal, plant and bacterial cells
After watching, attempt these questions before opening the answers. You can also use the written lesson below.
After watching 1: Where are proteins made?
Ribosomes. Ribosomes assemble proteins.
After watching 2: Which structure is present in ordinary plant cells but not animal cells?
Cellulose wall. Plant walls provide support.
What you'll be able to do
Animal and plant cells are eukaryotic: their genetic material is enclosed in a nucleus. Both have cytoplasm, a cell membrane, mitochondria and ribosomes. Plant cells also typically have a cellulose cell wall, a permanent vacuole and, in photosynthetic tissues, chloroplasts. Bacteria are prokaryotic: their DNA is not enclosed in a nucleus, and they may contain plasmids. Do not add mitochondria or chloroplasts to a bacterial diagram.
Ribosomes make proteins; mitochondria support aerobic respiration; the membrane controls exchange with the surroundings. Root-hair cells have a large surface for absorption, while sperm have a tail for movement and many mitochondria for energy transfer. Red blood cells have a shape and contents suited to oxygen transport. An explanation earns more than a list: state how a particular adaptation helps the cell perform its function.
A tissue contains cells working together, an organ combines tissues, and an organ system coordinates organs. The digestive system, for example, includes organs containing muscle, epithelial and glandular tissues. Cell differentiation creates specialised cell types during development. Many animal cells lose broad differentiation potential, while some plant tissues retain cells capable of dividing and differentiating throughout life.
Attempt these problems on paper before opening the worked reasoning. Explain your steps as well as giving a final answer.
Common mistakes to avoid
Key takeaways
Question 1: A micrograph shows DNA free in the cytoplasm and no nucleus. Which broad cell type is supported?
A bacterial/prokaryotic cell.
Check the assessed scope and practical or mathematical requirements.
An external explanation or interactive activity to use alongside the lesson. It may include extension material.
Close the notes and answer from memory. Revisit any explanation you cannot yet reconstruct.
Test yourself
Answer a few questions, then review anything you missed.
Start with the quiz above to check the key ideas. You can also choose another topic from the practice library.