Magic Melting Ice Cubes
Simon Quinnell, from the National Science Learning Centre, shows how to carry out some ‘magic’ at the Christmas dinner table using ice cubes, a plastic chopping board and a frying pan. When asked to feel the plastic and the metal, people usually describe the plastic as warmer to the touch. They are then surprised…
Magic Gas
Simon Quinnell, from the National Science Learning Centre, demonstrates the properties of gases in this surprising Christmas table experiment. He drops an effervescent digestion tablet into a wine glass containing some water to generate carbon dioxide. The carbon dioxide is heavier than air, and can be poured over a candle flame.…
Flying Tinsel
Simon Quinnell, from the National Science Learning Centre, demonstrates static electricity and charge using a balloon and a piece of plastic tinsel. Rubbing the balloon on a jumper builds up a negative charge on its surface. When the positively charged tinsel is dropped onto the surface of the balloon it is first attracted to…
Jumping Candle Flame
Simon Quinnell, from the National Science Learning Centre, shows how to carry out some ‘magic’ at the Christmas dinner table using a candle and a match. After letting the candle burn for a minute, Simon blows the flame out so that the smoke continues to rise above it. Then when a match is placed near the wick, the…
Jelly Liquidiser
In this Christmas table experiment, Simon Quinnell, from the National Science Learning Centre, demonstrates why pineapple should not be added to jelly. When he adds pineapple to a bowl of jelly, the jelly liquefies due to the action of an enzyme in the fruit which breaks down the gelatin. This is an example of a defence…
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…
Relative Humidity and Botrytis Infection
From Science & Plants for Schools (SAPS), this practical activity was developed for Scottish Highers specifications, but the protocol can equally well be used for other specifications. Students incubate raspberries at various humidities. The raspberries have been inoculated with the fungal pathogen Botrytis cinerea. A SAPS…
Sucrose and the Growth of Root Explants
From Science & Plants for Schools (SAPS), this practical activity was developed for Scottish Highers specifications, but the protocol can equally well be used for other specifications. Students sterilise seeds of white mustard (Sinapis alba) and allow them to grow in sterile water agar for several days. Explants are then…
Investigating Potato Cyst Nematodes
From Science & Plants for Schools (SAPS), this practical activity was developed for Scottish Highers specifications, but the protocol can equally well be used for other specifications. Students look at potato cyst nematodes, a serious pest of food crops. This is a good example of parasitism to study as: • it affects…
Examining Mycorrhizae
From Science & Plants for Schools (SAPS), this practical activity was developed for Scottish Highers specifications, but the protocol can equally well be used for other specifications. Students prepare and stain roots, and then examine them to establish the frequency of mycorrhizae. The practical activity helps students…