Science 1
| Science Around Our School - Investigating Science & Life Processes & Living Things |
INVESTIGATING & EXPERIMENTING
When you are doing an experiment, you need to know how to do certain things. First of all you need to know what your aim is. The aim is what your experiment is going to tell you or what you want to find out. The second thing you need to know is if your experiment is a FAIR TEST. For your experiment to be a fair test there should be only one variable. This will be what you are trying to find out as an experiment. Eg: If your experiment was to find out whether the size of a pot affects a plant, the one variable that changes would be the size of the pot. If you changed other variables like how much you watered each plant, locations, times when seeds were planted and the type of plant that would all effect the test. It would NOT be a fair test. The third thing you need to know is what equipment you are going to use. There are many pieces of equipment you will be able to use to help with your experiment.
Getting your results When you've completed the experiment, you will find the results. When you receive the results, you should try the experiment again to be sure that your results are going to be correct. If you are going to create an experiment you must do it safely. E.g.: If you want to see if a cup of water is just water or a mixture of other things, boil the water, do not drink it, it may be harmful!
Displaying Your Results If you want to show your results on paper, you can do it in several ways. The first is by using a bar graph. Eg: If your experiment was to see if the size of pot mattered, you could do this on a bar graph by having the y axis as the plant height and the x axis as the pot type. The second way is by using a line graph. Eg: Using the same example, if there was a straight line going diagonally across the grid, with the pot size on the x axis and the height of plant on y axis again. If you want to find out how big the plant will be, find 6cm on the x axis then follow the grid up to the line, then from the line to the number on the y axis. Beware though, bar graphs are used for different information than line graphs. Line graphs show continuous data like temperature or noise level. Bar graphs show discrete data (not continuous) like names, favourites etc.
Conclusions All experiments end with a conclusion. A conclusion is what you find out by doing the experiment. In your conclusion ideally there should be a comparison and and 'er' at the end of one of the words Eg: The HARDER you hit the drum, the LOUDER the volume. This is a good way to explain experiments to younger children and people who don't understand science very well. It makes it clearer and simpler.
LIFE PROCESSES & LIVING THINGS
Looking at life Living things are called living organisms. All living things do the seven life processes. A way of remembering them is by MRS.NERG.
M-Movement - humans move by walking and running and plants move to face the sun. R-Reproduce - every living thing reproduces to make more of their species. Otherwise the race would die out and become extinct. S-Sensitive - living things react to changes in their surroundings. It is important for a plant or animal to be kept in its natural surroundings. N- Nutrition - taking in food. E-Excrete - getting rid of waste. R-Respire - living things are active and breathing. G- Grow - growing into adults, getting ready to reproduce.
Dead or Alive Living organisms are made up if cells. Cells are so tiny you will need a microscope to see them. Things that are dead still have cells for example, a dead leave. If things never lived they don`t have cells they have particles. Things are either: Living, dead or non-living (never lived).
THE HUMAN BODY The Brain The human brain is at the centre of the skull (cranium is the more scientific word). It receives nerve signals from below the surface of the skin. It also controls the body to move, respire and stores information in the mind. The right side of the brain controls the left side and the left controls the right. If you become paralysed from the neck down the brain cannot do anything below the neck. You can get internal bleeding where you may hit your head very hard on the floor and it starts bleeding inside. Blood comes out of your ears and it becomes too much for your brain which is sucked down the spinal cord and you then die.
The Skeleton The skeleton is very important. Without it you would basically be laid on the floor without being able to move or even stand. Your organs would also not be protected.
The skeleton has three main jobs:
Do you recognise these body parts?
Movements of the human body You need muscle and bones to move. If you have no bones you will just be a pile of rubber on the floor like jelly. You move your legs and arms by muscle and bones, even if you move your head you are using at least 1 muscle. Elbow, shoulder and things like that have joints. When the brain sends a message to a limb, the muscles contracts and relax. The muscles around the bones always work in pairs. If you pull your arm up you can see your muscle contracting while the other muscle relaxes. Muscles are attached to your bone by tendons, the bones are held together by ligaments.
Circulation The heart pumps blood around the body, the blood carries food and oxygen to the bodys cells and muscles. As the blood travels it goes through three blood vessels, which are arteries, veins and capillaries. Arteries carry blood away from the heart and are the biggest blood vessel. Veins carry blood back to the heart and are the second biggest blood vessel. Capillaries allow food and gases to move in and out of the blood and are the smallest blood vessels. The heart is a muscle and when it beats, blood is pumped out of two arteries. Blood is carried back into the heart by two veins. The arteries carry blood to the lungs to pick up oxygen and gases and goes back to the heart. When it does this it lets carbon dioxide into the lungs which is breathed out. Arteries are hidden right in the middle of your limbs. If you cut an artery you could die within two minutes.
Lungs and Breathing When you breathe you recieve Oxygen and Carbon Dioxide . This then travels down your wind pipe into your lungs, then travels through the outside of the lung, it is then taken round the body by the blood. Some blood cells collect Oxygen. We don't need Carbon Dioxide but we need Oxygen Organs There are lots of organs including the ear. The ear is for hearing. The heart is for pumping blood round the body to keep you healthy. The eye is used for seeing. The lungs bring in oxygen and gets rid of the Carbon Dioxide. The liver stores chemicals. The stomach collects the food and dissolves it. The kidney cleans the blood and makes waste. The bladder excreats the food and makes you go to the toilet.
Teeth In your mouth you have three types of teeth:
Molars: These teeth are at the back of your jaw; they crush your food and grind it up until it is ready to swallow. Incisors: These teeth are at the front of your jaw; they cut the food up ready for the molars to grind up. Canines: these teeth are around the side of your jaw; they tear your food to pieces.
The two sets of teeth you have are milk teeth, for ages six months to five years, and adult teeth, from five onwards. (unless you lose them before them). To prevent tooth decay, you should:
Healthy Living To stay healthy and keep fit you need to eat sensibly, take exercise regularly and avoid health risks. Eating a balanced diet is important .To eat a balanced diet you need these seven food types: protein, carbohydrate, fibre, fats, vitamins, minerals and water.
A healthy body needs exercise because it strengthens muscles, it develops the lungs, it helps body coordination develop, it uses up food for energy and it can help you sleep at night. Smoking causes heart attacks and lung cancer. It forms a layer of tar on your lungs which makes breathing harder. Sniffing glue and solvents is dangerous and is addictive. Alcohol in small amounts is not dangerous but it slows down your reactions. Drugs can be dangerous if misused. Many are addictive and can cause damage to the brain.
Fighting Diseases Disease kills many people in the world every day but potentially could kill many more but there are many ways to combat it. One way is by simply being very clean. If you are cooking in the kitchen you must be especially careful. They're are many ways to catch disease but many ways to stop it. You can stop disease from spreading through most food by covering it. If you store food in a fridge you must make sure the raw meat is separated from the cooked meat . In the kitchen, be sensible with food. Make sure you cook food properly. You must store food in the fridge and keep it covered. Keep raw meat away from cooked meat and preserve food properly. Diseases can be cured with medicines from your local doctor, such as antibiotics taken as injections or pills. Personal hygiene is important. Another way of catching disease is by coughing in front of people and by not washing your hands after going to the toilet.
Microbes and diseases Micro-organisms are very tiny living things, so the only way to see them is through a microscope. Millions of micro-organisms are everywhere in the soil, air, water and the human body. Some micro-organisms are good to use but some are dangerous. Yeast is an micro-organism, it is used for making bread and butter. Dangerous micro-organisms cause dieses such as the flu and chicken pox. Ways of spreading micro-organisms are insect bites, infected food, coughs and from touching infected food.
Life cycles There are 8 stages in life the first one is fertilised egg, the second one is embryo, the third one is a baby, the fourth one is child, the fifth one is puberty, the six one is adult, the seventh is old age, the eighth one is death. Everybody is under one of these categories. The way of life is that your parents have children and you have kids and so on. This is because your dad?s sperm inserts into your mums womb and forms an egg. That is how the human life cycle works.
Plants Plant Groups There are two different groups , non flowering plants and flowering plants. Here are four non-flowering plants: grasses, cereals, garden shrubs and coniferous .
Parts of a Flower There are four main parts of a flower they are roots, leaves, stem and flower. The carpel contains the eggs and the anther contains the pollen.
Flowers The flowers attract insects by the smell and what it looks like. The male cells make pollen and it joins to the egg (female cells). Some part of the flower dies and what is left becomes new fruit with seed.
Leaves The green chlorophyll the leaves need sunlight it changes into Carbon dioxide. Carbon dioxide, gas and water change into food. It?s called photosynthesis.
Stem To hold the plant up it needs water and minerals .It carries to the rest of the plant.
Root Roots pull the plant to the ground because it will blow away. They have hairy roots because to soak up water. The roots need Nutrition to eat.
Nutrition Animals can move but plants cannot move they stay where they are Plants can make their own food in presents of sunlight , water ,carbon dioxide and chlorophyll in the green leaves use light to change carbon de oxide and water into the food and oxygen. Those animals who eat plants get indirectly get sunlight. Photosynthesis means using light to make food. Chlorophyll is also green stuff.
After the pollen and eggs have joined and made seeds and have been dispersed seeds begin to germinate. Germinate means, when seeds begin to grow. Seeds need three things to germinate; there is a very easy way to remember it. WAW. This stands for water, air, warmth, if these things are correct, seeds will germinate. Seeds crack and roots begin to grow, remember roots grow down into the soil. Then the roots begin to grow but this time towards the light, green leaves now grow and the plants can make food. Seeds The Fertilised Egg becomes a seed. a) The flower dies and leaves behind a fruit with the seed. b) The ovary becomes the fruit and contains the seed. c) Some fruits are soft and juicy and some are dry. Seed Dispersal Involves the Scattering of Seeds. The fruit and seed must be carried away from the parent plant to stop over crowing. Three ways to Disperse a fruit with its seed . a) By wind. Some times the fruit get blown by the wind . b) By animals. The fruit are juicy so they are eaten and excreted out by animals. c) By Explosion.The fruit skin dries up and split open so shooting out seeds.
Variation and Classification Sorting out living things You can sort everything out into two different sections. These are animals and plants. From animals, you can split this group into another two sections, which are vertebrates and invertebrates. A vertebrate is any animal with a backbone. Vertebrates are now split into five groups. These are mammals, fish, birds, reptiles and amphibians. Examples of mammals are humans, elephants and whales. Examples of fish are sardines, trout and sharks. Examples of birds are thrush, robin and hawk. Examples of amphibians are newts, toads and frogs. Lastly, examples of reptiles are snakes, alligators and crocodiles.
Using Keys Keys are used to work out what unknown creatures are. A key has several questions with usually two possible answers to each. If you have worked through the key properly then you will have the true identity of the unknown creature.
Invertebrates Invertebrates are animals without backbones. Invertebrates are split into three groups insects, arachnids and molluscs. Insects have six legs and three body parts, arachnids have eight legs and two body parts and molluscs often have a slimy foot or a shell, eg. Snails, slugs and octopuses. HANDY REMEMBERING TIP: The word insect has six letters in it so insects have six legs; the word arachnid has eight letters in it so arachnids have eight legs.
Which groups do these living things belong to?
Plant Groups There are two different groups , non flowering plants and flowering plants. Here are four non-flowering plants grasses, cereals, ferns and coniferour trees.
Places to Live Humans can travel all over the world because they can where clothes and to match the place they are in also they can build a home to suit it as well. Where an animal or plant lives is called a habitat. A habitat for a certain thing provides food and shelter for it. For example a frog lives on land and in water the reason why is it lays frog spawn in the water and goes ion land the rest of the time apart from when it fells like a dip. It needs damp air other wise it dries out and dries and die. Where the frog lives it can get food like juicy slugs. Animals and plants are adapted to their habitats they have special features to help them survive in their environment. For example, the roots on a cactus are long so they go far under ground to get water. A squirrel has long claws to help it grip to the tree to help it climb it. The other can close its eyes and nostril under water.
Adapting to other habitats Worms are adapted from soil, they live there so they can hibernate and they like digging in the soil. They have moist skin helps the oxygen pass through. They have a pointed head to help them dig though the soil. Woodlice live under rocks and blocks of wood to hide. They have a firm, flat body to crawl under the wood or rock. They have a child to protect them from dying.
A Field Habitat
Adapting To Hot and Cold A desert rat is adapted to the hot desert because of its large ears. Its long tail helps it to balance. It has good hearing and good eyesight to help it be active at night. A desert rat has thin fur to keep body heat in at night. A squirrel has sharp claws so it can climb up tree and it has good hearing to hear predators.
Adapting to Water Animals such as fish and frogs need special features to survive in a water habitat. Fish have sensitive areas that can smell over long distances to detect food, gills, fins and a streamlined body. Frogs have sensitive areas that can pick up vibrations in the water, powerful back legs, a wide mouth and sticky tongue, lungs, moist skin and webbed feet.
Food Chains Food chains meaning: living things feeding on other living things. For example:
Lettuce > Slug > Thrush > Hawk.
> = is eaten by
If the lettuce dies out then the chain will be shorter and the slug will die out because they have nothing to eat.
And then evenatually it will mean the hawk will die with no food to eat or certainly have to search harder for more types of other food to compensate. If an animal eats another the animal is prey.
In this food chain the lettuce is the producer (It produces its own food), the slug & the thrush are the prey (they are living food for something else) and the hawk & the thrush are predator (they hunt for & eat other animals)
Food Web A Food Web is a series of food chains all interlinked. Unlike the Food chain, a creature can be shown to eat more than one producer. They show the complex relationship between animals and how the death of one type of animals will affect all the other animals in the web.
Protecting the Enviroment When Humans use fields to build houses and buildings they kill lots of animals. This means that it mucks up food webs so animals become rarer and rarer until they become extinct. A good example of this is the Dodo which was wiped out about 300 years ago. |
