Cell

In the syllabus and the exam

The cell is introduced early in Form 4 as the foundation for the whole 'Cell Structure and Function' topic, and questions on it range from simple labelling of a light-microscope diagram in Paper 1 to structured comparisons between plant and animal cells, or prokaryotic and eukaryotic cells, in Paper 2. Candidates are expected to know that all living organisms are built from one or more cells, that cells are organised into tissues, organs and systems in multicellular organisms, and that a cell's structure closely matches the specific function it performs, a theme examiners return to repeatedly across chapters. A common area of confusion is distinguishing a cell from an organelle: a cell is the whole living unit bounded by a membrane (and, in plants, a cell wall), while an organelle is one specialised structure inside that cell, such as the nucleus or a mitochondrion; describing the nucleus as 'a type of cell' is a frequent and costly error. Another point often tested is the difference between prokaryotic cells (such as bacteria, which lack a membrane-bound nucleus) and eukaryotic cells (such as those of plants, animals and fungi, which have one), since this distinction underpins later work on microorganisms and biotechnology. Because this chapter introduces vocabulary used for the rest of the syllabus, weak recall of basic cell terms is one of the most common reasons candidates lose easy marks in later chapters on transport, division and genetics, even when they understand the more advanced concept being tested.

Example

A single onion epidermal cell viewed under a light microscope shows a cell wall, cytoplasm and a clearly visible nucleus, confirming it is a plant cell.

Related terms

OrganelleTissueCell differentiation

Source:SRC-DSKP-EN