Lucky dip. Any answers? Nooks and crannies. Semantic enigmas. The body beautiful. Red tape, white lies. Speculative science. This sceptred isle. Root of all evil. Ethical conundrums. This sporting life. Stage and screen. Birds and the bees. Or is it some kind of placebo, developed by our parents who have lied to us for years in order to stop us as small children from crying when stung Many flowers, whose colour and fragrance evolved to entice pollinators, even have petals faced with microscopic conical cells to help bees in the breeze get a grip.
But some highly bred roses rely on us to propagate them; their blooms have several layers of petals that win horticultural prizes but barricade insects from nectar and pollen, rendering natural pollination impossible. Flowers send signals to various creatures, but for a long time human beings have used the rose to signal to one another. Roses were twined over the triumphal banners of Roman armies, and Nero had swaggering banquets so jammed with blossoms that the smell was overwhelming.
The tall, open bushes of the stunningly fragrant pink damask rose, grown in Bulgaria, Turkey and central Iran, are the main source of flavourings and scent. Rose water, which is produced in quantity by boiling petals in water and condensing the vapour, is used in regional confectionery such as Turkish delight.
However, attar, the fabulously concentrated oil of roses coveted by perfumiers, requires Herculean effort to produce: 7, blooms gathered at their early-morning peak and distilled the same day yield just a teaspoonful of oil. The little evergreen coffee tree began life somewhere near the forested mountains of southwestern Ethiopia, and its elliptical leaves with crinkled edges, shiny and dark above and pastel-pale underneath, still prefer shade.
In full flower, coffee is a spell-binding but ephemeral joy; for just a couple of days, thousands of delicate white blossoms can festoon a single tree. More than 1, years ago, thanks to genius or good fortune, beans were roasted, pounded and added to hot water. The resulting fineflavoured, stimulating brew spread via Yemen throughout the world. When its leaves drop, their caffeine leaches into the soil, impeding rival plants.
Perhaps dandelions are just too common to be appreciated properly. Their flower heads, composed of dozens of individual florets, create pretty patches, or even carpets, of intense yellow to temperate open fields and verges, and punctuate the monotonous green of garden lawns.
Often regarded as weeds, they certainly spread easily. Dandelion stems, and especially roots, contain sticky white latex that coagulates to seal any wounds from infection. Dandelion latex and the latex from rubber trees are remarkably similar. In the s, the Russians planted square miles of dandelions in eastern Europe and successfully produced rubber from them.
After World War Two, with the Far Eastern rubber supply stabilised, dandelion rubber became uneconomical. Recently, however, with increasing pressure on tropical forests, research in Europe and the United States has focused on breeding high-yielding Russian dandelion, and tyres of dandelion rubber are already on the market. Sugar cane may be a stunningly tall grass, but it is drawrfed by many of the 1, or so species of bamboo - the biggest grasses of all - that are found around the world, especially in warm, wet climates.
The giant timber bamboo, native to China, is awesome. Emerging vertically from a circular splay of roots partially above the ground, the individual stems, or 'culms', can soar to 80 feet, and in ideal conditions can grow more than three feet a day.
Finally, in Part 3, students use Universal Indicator paper to identify the pH of nettle stings, and compare this with the pH of the dock saps. Watch the video of this practical on our YouTube Channel. Image of nettle leaf showing stings. Close up image of sting. Sign up now. Investigating leaf adaptations - why do nettles sting? Finally, in Part 3, students use Universal Indicator paper to identify the pH of nettle stings, and compare this with the pH of the dock saps Watch the video of this practical on our YouTube Channel.
Filter secondary resources by Key Stage KS1. Post Topic Adaptation. Agriculture and farming. Climate change. Ecology and evolution. Fertilisation and cell cycles. Inheritance and genetics. GM and Selective breeding. Movement in and out of cells.
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