Concentrations and Dilutions: a Survival Guide
This resource from Science & Plants for Schools (SAPS) is presented as a survival guide for students, describing how to handle numbers correctly, standard form, the use of scientific calculators, the definition of a mole, calculating molarity, Avogadro’s number, how to express concentrations and how to calculate dilutions.…
Symbols and Units: a Survival Guide
From Science & Plants for Schools (SAPS), this guide explains the rules for using symbols and units which students will meet in their science courses and reminds of the importance of using them, and writing them, correctly. The guide contains six sections: 1. SI base units 2. Derived units 3. Secondary units and prefixes 4.…
Carnivorous Plants
This resource from Science & Plants for Schools (SAPS) describes the work of Charles Darwin on carnivorous plants to determine what causes the leaves to curl up when stimulated. Darwin’s experiments are very easy to repeat. These teachers' notes describe several investigations which students could carry out, such…
Investigations with Venus Fly Traps
In this activity from Science & Plants for Schools (SAPS), students investigate what causes a Venus’ Fly Trap to shut. These experiments are related to a series of investigations that Darwin carried out as part of his work on evolution and adaptation and background information on this is provided. Students use a brush to…
Wild Oats on the Move
In this experiment, from Science & Plants for Schools (SAPS), students are required to make observations about wild oat seeds. Using a petri dish, glass jar, filter paper and water, students can recreate the conditions of a greenhouse. They can then observe the changes to direction of the awn (the long hair at the top of the…
Plants as Chemical Factories
These teachers' notes from Science & Plants for Schools (SAPS) describe how students can investigate the trichomes on the surface of vascular plants, including hairs and glandular hairs, using a microscope. Students can use plants like thyme or sage to investigate these structures in the classroom. The activity can…
Adaptation, Natural Selection and Winged Fruits
In this activity from Science & Plants for Schools (SAPS), students investigate the role of natural selection in evolution by considering the extent to which the winged fruits from a tree are adapted for successful dispersal. This practical approach to studying natural selection and competition encourages students to formulate…
Fruit Juice Production and Enzyme Recovery
Produced by Science & Plants for Schools (SAPS), in this investigation, students look at the effectiveness of enzymes used in the commercial production of fruit juices. Fruit juice companies use enzymes to break down the cells walls within the fruits and release the liquids and the sugars which make up the fruit. Pectinases,…
What Determines the Number of Spines on a Holly Leaf?
Produced by Science & Plants for Schools (SAPS), this activity enables students to: • develop knowledge and understanding of structural defence mechanisms in plants • develop problem solving skills • demonstrate the processing of information and use of calculations The investigation looks how the number of…
The Effect of Phosphate on the Enzyme Phosphatase
Produced by Science & Plants for Schools (SAPS), this investigation looks at end-product inhibition of the enzyme phosphatase. The investigation is designed for students following a Scottish Highers course but it is equally useful for other post-16 courses in biology. This investigation involves an acid phosphatase extracted…
Stomatal Opening and Closing in Commelina Communis
Produced by Science & Plants for Schools (SAPS), this investigation looks at stomatal opening and closing in Commelina communis (Asiatic dayflower). This is achieved by varying the turgor of the guard cells by bathing lower epidermal peels in solutions of different osmotic strengths. Changes in guard cell turgor results in changes…
Calculating the Mitotic Index of a Growing Root Tip
Produced by Science & Plants for Schools (SAPS), this investigation enables students to investigate the process of mitosis in a growing root tip. The mitotic index is the fraction of cells in a microscope field which contain condensed chromosomes. In this activity students prepare and stain root tips. Garlic cloves, bought…
The Response of Leaf Discs to Green Light
Produced by Science & Plants for Schools (SAPS), this investigation enables students to investigate the response of leaf discs from sun and shade plants to green light Leaf discs from a sun plant and a shade plant are put in a sodium hydrogen carbonate solution. The rate of photosynthesis is seen by how long it takes the leaf…
The Effects of IAA on Root Growth
Produced by Science & Plants for Schools (SAPS), this activity enables students to investigate the effects of the plant hormone indole acetic acid (IAA) on root growth in mustard seedlings. Different concentrations of IAA appear to have differing effects on root growth. These effects may vary from one species to another but…
Competitive and Non-competitive Enzyme Inhibition
Produced by Science & Plants for Schools (SAPS), this activity enables students to investigate the effect of competitive and non-competitive inhibitors on the enzyme beta-galactosidase. The chemical ONPG (o-nitrophenyl beta-D-galactopyranoside) is degraded by the enzyme beta-galactosidase. The product is yellow and so the…
Induction of the Lac Operon in E.coli
Produced by Science & Plants for Schools (SAPS), this activity enables students to look at the induction of the lac operon in the bacterium Escherichia coli (E. coli). Lactose is found in milk but not in many other environments. The enzyme, beta-galactosidase breaks down lactose to glucose and galactose. E.coli switch on the…
Gel Electrophoresis of DNA
Produced by Science & Plants for Schools (SAPS), this activity enables students to look at the gel electrophoresis of DNA treated with restriction enzymes. It will help to develop a knowledge and understanding of the cutting of DNA with restriction enzymes. In the experiment, a batch of DNA is digested by two different restriction…
Estimating the Glucose Concentration of a Solution
Produced by Science & Plants for Schools (SAPS), in this investigation, students look at the concentration of glucose in isotonic sports drinks. This enables students to see if the drinks are, in fact, isotonic with the blood. In this investigation, students first produce a standard curve by testing glucose solutions of known…
The Effects of Mineral Concentrations on Plant Growth
Produced by Science & Plants for Schools (SAPS), this activity enables students to investigate the effects of different concentrations of nitrates, phosphates and potassium on the growth of radish seedlings. After sowing, the radish seedlings are kept well watered, in a warm temperature under constant illumination. The investigation…
Sweet or Sour?
Produced by Science & Plants for Schools (SAPS), this investigation looks at the taste of different fruits and vegetables. Domesticated fruits and vegetables have all been selectively bred so that they contain a particularly attractive taste for humans. In a ripe fruit, flavours are produced by a combination of compounds such…
Respiration Changes During Fruit Ripening and Storage
This practical activity, from Science & Plants for Schools (SAPS), investigates the process of respiration. Suggestions are given for looking at different fruits or vegetables and measuring the respiratory rate during the ripening process. Possible investigations include: • Does the rate of respiration vary during the…
Doubling and Dabbling in Duckweed
Produced by Science & Plants for Schools (SAPS), the investigations suggested in this resource use duckweeds. These seem to be simple plants - small, green, and with no flowers. However, this simplicity makes them ideal experimental organisms for investigations into a variety of environmental topics such as the effects of pollution…
Autolysis in Yeast
Produced by Science & Plants for Schools (SAPS), this investigation looks at the autolysis, or cell death, of yeast. This is important, as many food production processes require the living yeast to be killed. In the process of autolysis it is important to try to find at what point in the process the cells actually die. During…
Investigating Antimicrobials
From Science & Plants for Schools (SAPS), these materials encourage students to use disc diffusion tests to investigate antibacterial or anti-yeast properties. A wide range of products, both synthetic and natural, claim to have microbicidal properties. Students can test these claims. Experimental method and materials are given…
Inhibitory Growth Effects of Conifers
Produced by Science & Plants for Schools (SAPS), this resource looks at the compounds produced by conifers that inhibit the growth of other plant species. Conifers, such as pine trees, contain compounds which inhibit the growth of other plants. They tend not to have other species of plants growing under them and pine needles…
Antifungals: Inhibition of Fungal Growth
Produced by Science & Plants for Schools (SAPS), this resource encourages students to investigate the effects of various antifungal treatments on the growth of yeast. Antifungal treatments available from pharmacists include: • Canistan • Daktarin • Diflucan A suggested method, with appropriate technical…
Ethene: Plant Growth and Ripening
Produced by Science & Plants for Schools (SAPS), this investigation looks at the effects of ethene of fruit ripening. Ethene is a colourless gas and is produced by plants, acting as a plant growth substance. Its presence can be detected using a simple bioassay using germinating seedlings. Details of this assay are included…
Enzyme Activity in Fruits and Vegetables
Produced by Science & Plants for Schools (SAPS), these materials give a range of suggested activities that investigate enzyme activity in ripening fruit. These include: • the changes in enzyme activity during ripening and storage • the activity of the same enzyme in different species • the loss of an enzyme…
Colour Changes in Ripening Fruits and Vegetables
Produced by Science & Plants for Schools (SAPS), these investigations look at how pigments change during the fruit ripening process. The green colour of the unripe fruit is due largely to the presence of chlorophylls, and the development of different colours during ripening is due to the disappearance of these pigments and…
Catechol Oxidase Activity in Fruits and Vegetables
Produced by Science & Plants for Schools (SAPS), this investigation looks at the activity of the enzyme catechol oxidase (also called polyphenoloxidase). Found in a wide variety of plants, it is responsible for the darkening observed when many fruits or vegetables are cut or bruised. Details of the materials needed and a suitable…
Water Potential During Ripening and Storage
This investigation, produced by Science & Plants for Schools (SAPS), shows how students could investigate the changes in water potential of fruits and vegetables during ripening and storage. Simple biomechanical and biochemical tests are described which can be used to measure the effects of osmosis, when placing plant tissues…
Ideas for Extended Projects with Plants
Produced by Science & Plants for Schools (SAPS), this resource suggests a range of ideas for extended investigations into plant growth and physiology. Each suggestion is given a brief description but details of experimental methods are not provided. The investigations suggested include: • What causes dandelion leaves…