Theory question 101
Cell Structure and Organisation(a) (i) Explain briefly the cell theory (ii) Name two scientists who contributed to the development of the cell theory
(b) Make a large labelled diagram of a typical plant cell
(c) List three ways in which a typical plant cell differs from a typical animal cell
(d) State one difference each between Hydra and the mammals with respect to (i) level of organisation (ii) symmetry (iii) number of body layers.
Show the model answer
(a)(i) All living things are made of cells; the cell is the basic unit of structure and function; new cells come only from existing cells
(ii) Any two: Robert Hooke, Matthias Schleiden, Theodor Schwann, Rudolf Virchow, Felix Dujardin
(b) Large drawing with title; labels: cellulose cell wall, cell membrane, cytoplasm, large vacuole, nucleus, nucleolus, chloroplasts, mitochondria
(c) Plant cell has a cellulose cell wall (animal has none); has chloroplasts; has one large central vacuole (animal has small or none); regular shape; stores starch, not glycogen; no centrioles
(d)(i) Hydra – tissue level; mammals – system level
(ii) Hydra – radial symmetry; mammals – bilateral symmetry
(iii) Hydra – two layers (diploblastic: ectoderm and endoderm); mammals – three layers (triploblastic)
Each difference must compare both organisms.