Cell Structure
Overview
Everything a living thing does, it does with cells. A cheek cell, an oak leaf cell and a bacterium sitting on a door handle are all built from the same short list of parts, arranged differently and used for different jobs. Learn that list properly and a great deal of the rest of biology stops being memory work and starts being reasoning.
In this lesson you will name the parts of animal, plant and bacterial cells and say what each one does. You will meet the one distinction that matters most, between cells that keep their genes inside a nucleus and cells that do not, and you will practise the skill the examiners really want: looking at an unfamiliar cell, spotting what it has too much of, and working out what it must be for.
Objectives
- Most animal cells (eukaryotic cells) have the following parts: a nucleus, which controls the activities of the cell; cytoplasm, in which most of the chemical reactions take place; a cell membrane, which controls the passage of substances into and out of the cell; mitochondria, which is where most energy is released in respiration; ribosomes, which is where protein synthesis occurs.
- In addition to the above, plant cells (eukaryotic cells) often have: chloroplasts, which absorb light energy to make food; a permanent vacuole filled with cell sap. Plant and algal cells also have a cell wall made of cellulose, which strengthens the cell.
- A bacterial cell (prokaryotic cells) consists of cytoplasm and a membrane surrounded by a cell wall; the genes are not in a distinct nucleus; some of the genes are located in circular structures called plasmids.
- Cells may be specialised to carry out a particular function. Students should be able, when provided with appropriate information, to relate the structure of different types of cell to their function in a tissue, an organ, or the whole organism.
Mind map
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Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Cell Structure. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which part of a cell controls the passage of substances into and out of it? A. The nucleus B. The cell wall C. The cell membrane D. The cytoplasm Answer: C
- Which structure is found in a plant cell but NOT in an animal cell? A. Ribosome B. Chloroplast C. Mitochondrion D. Cell membrane Answer: B
- Where does protein synthesis occur in a cell? A. In the ribosomes B. In the mitochondria C. In the vacuole D. In the cell wall Answer: A
- Which statement about a bacterial cell is correct? A. Its genes are held in a distinct nucleus B. It contains chloroplasts C. Some of its genes are in circular plasmids D. It has no cell wall Answer: C
- A cell contains a very large number of mitochondria. What does this suggest? A. It makes a lot of protein B. It releases a lot of energy by respiration C. It photosynthesises rapidly D. It stores a lot of water Answer: B
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