Background information on the methods and varieties used to demonstrate the cultivation of plants without the use of chemical pesticides is provided. Discussed are species and variety selection, growing plants from seed and from seedlings, soil preparation, using cuttings, useful crops, and pest control. (CW)

Two representations useful in teaching transmission genetics are described. Details of the representations and problem solving using these instructional aids are discussed. The importance of developing representations which help remedy specific difficulties that students commonly encounter is stressed. (CW)

A method of obtaining a crude mitochondrial extract from sheep and beef heart is described. The respiratory substrates succinate and malate are examined as well as the inhibitory effect of malonate. An interface with a microcomputer for plotting colorimeter results is discussed. (Author/CW)

Described is the generative learning strategy, an approach which encourages pupils to discuss their out-of-school ideas about plant breathing, drinking, wood production, soil, minerals, and leaves, and assist them in linking appropriate ideas together to form an explanation of the origin of plant materials. (CW)