Did you know that you have more than a trillion atoms of uranium in your body right now and hundreds of these atoms are radioactively disintegrating every day? So you are radioactive right now. Where do these come from? From the food we eat and the air we breathe (and they’ve always been there). [Demonstration using a Geiger counter] But if this is the case, how can radiation cure cancer? Remember – when a cell gets ‘zapped’ with radiation, one or more of the within its DNA may lose electrons which can cause it to produce an inexact copy of itself when it comes to replicating. Or it (the cell) may be damaged to such an extent that it dies completely. With radiation treatment the aim is to zap existing bad cells with enough ionising radiation that all the bad cells die off rather than reproduce. The trick of course is to hit the bad cells but not any neighbouring good cells. Which is easier said than done. Which is why we need trained radiologists. These folk look at the tumour and determine how much radiation is needed and where the best place to aim it is. Quiz question: does radiation give you superpowers? Yes – mutations for evolution There are background levels of radiation everywhere, and doses we can easily endure with no ill effect Tumours An individual cell may grow and divide to form a mass of identical cells called a tumour. Two benign and malignant • Benign tumour – Cells soon stop dividing and do not invade tissues. • Malignant tumour – Uncontrolled division of cells which can then invade surrounding tissue. Cancer • A malignant tumour is also known as a “cancer”. • A cancer is a mass of which have lost the ability to control the rate and frequency of mitosis, and which invade and disrupt surrounding tissue. • Cancerous cells can break off from the tumour and travel in the circulatory system to new sites to form new tumours. • This is known as metastasis. Causes of Cancer • Certain genes are crucial to maintain normal cell behaviour. • If these genes are mutated, cancers can result. • genes are known as oncogenes. • Carcinogens are cancer-causing agents cause mutations in oncogenes. • Examples: – cigarette smoke – UV radiation – certain viruses
Due to genetic manipulation, 90% of broiler chickens (chicken bred specifically for meat production) have trouble walking. Encourage your school cafeteria to go meatless on Mondays to protest. Sign up for . Two-thirds of Central America’s rainforests have been destroyed, in part to raise cattle whose meat, typically found in hamburgers and processed meat, is exported to profit the US food industry. Nature red in tooth and claw Did you know that animals get eaten alive all the time when Disney isn’t around? Battle at Kruger as a baby buffalo is caught in the jaws of four lions, then acts as the rope in a tug of war between the lions and some crocs, and finally gets rescued by her extended family. Simply amazing Was I the only one rooting for the lions? Baby lions have to eat too you know. How can you call yourself a lover of nature and still be appalled by these images? FIONA GARTLAND WALKERS IN Dublin’s Herbert Park at the weekend saw nature at its most beautiful and brutal when a Grey Heron hunted and fed on day-old ducklings on the banks of the Dodder. Wildlife photographer Paul Hughes was present to witness the scene as the majestic bird swallowed whole two chicks from the brood of a Tufted Duck. The mother attempted to hide the ducklings among reeds and the birds dived below the water to try to get away from the accomplished fisherman. But once he had spotted them, they were any easy target. “The swooped in and grabbed the chick and there was pandemonium; the mother was going wild and the other ducks were quacking,” the photographer said, “but there was nothing she could do.”
Why should Energy be one of our Ten Great Ideas? Be prepared to be surprised. Because it is the glue that ties all of science together. Because nobody knows what energy actually is. Because while Energy does get a mention in our Junior Cert and Leaving Cert Science textbooks, there is no attempt to state its centrality in all of science – how it is the one concept that ties everything else together – and how nobody knows what energy actually is. At the end of this lesson students should be able to do the following that most of the energy in the universe is missing State why energy is such a single concept in Science State why energy is such a difficult concept to understand Explain the analogy between energy and Activities Energy conversions Large Pendulum (hanging from teacher’s desk) Resources Youtube Test Questions Work – force x distance Example The Principle of Conservation of Energy states that energy cannot be created or destroyed but can only be converted from one form to another. hardest to It’s not tangible. Words, Science and Learning, - quote p.64 Energy and Food Calories Physics article - Crease History of Energy Einstein – mass can ‘disappear’. Atomic bomb. 90% bulbs Perpetual Motion See energy clips in thephysicsteacher Cold fusion