Questions and Answers

State that some substances move into and out of cells by diffusion through the cell membrane

State that the energy for diffusion comes from the kinetic energy of random movement of molecules and ions

Describe diffusion as the net movement of particles from a region of their higher concentration to a region of their lower concentration (i.e. down a concentration gradient), as a result of their random movement

Calculate magnification and size of biological specimens using millimetres as units

State and use the formula: magnification = image size ÷ actual size

Describe the meaning of the terms: cell, tissue, organ, organ system and organism as illustrated by examples given in the syllabus

State that specialised cells have specific functions, limited to: (a) ciliated cells – movement of mucus in the trachea and bronchi (b) root hair cells – absorption (c) palisade mesophyll cells – photosynthesis (d) neurones – conduction of electrical impulses (e) red blood cells – transport of oxygen (f) sperm and egg cells (gametes) – reproduction

State that new cells are produced by division of existing cells

Describe the structure of a bacterial cell, limited to: cell wall, cell membrane, cytoplasm, ribosomes, circular DNA, plasmids