| A | B |
|---|
| habitat | the place where an organism lives |
| the differences between organisms | variation |
| variation which can have any value | continuous |
| variation which means that measurements must fall into categories | discontinuous |
| examples of continuous variation | height and weight |
| examples of discontinuous variation | eye colour and shoe size |
| species | organisms which can reproduce to create fertile offspring |
| fertile | able to reproduce |
| infertile | unable to reproduce |
| sterile | another name for infertile |
| hybrid | offspring produced when members of different species reproduce |
| hybrids are | infertile |
| in an investigation you choose | the values of the independent variable |
| in an investigation you measure | the values of the dependant variable |
| in an investigation you keep | the values of the control variables the same |
| environment | the conditions in a habitat |
| physical environmental factors | light and temperature |
| adaptations | features which help an organism survive |
| polar bears have white fur | for camouflage |
| polar bears have thick fur | to keep them warm |
| polar bears have small ears | to stop them losing too much heat |
| polar bears have rough soles | to grip the ice |
| polar bears have large feet | to stop them sinking in the snow |
| cactuses have no leaves | so they lose less water |
| cactuses have long roots | to absorb as much water as possible |
| cactuses have a thick stem | to store water |
| jack rabbits have large ears | to keep them cool |
| jack rabbits do not need to drink | they get water from their food |
| jack rabbits have large hind limbs | so they can run quickly to avoid predators |
| community | all the animals and plants that live in a habitat |
| ecosystem | the community of organisms and the physical environmental factors in a habitat |
| inherited | features which come from parents |
| identical twins | develop from the same fertilised egg |
| environmental variation | not inherited |
| examples of genetic (inherited) variation | eye colour and colour blindness |
| examples of environmental variation | hair length and leaf size |
| seasonal changes | occur during a year |
| daily changes | occur everyday |
| nocturnal | animals which are active at night |
| deciduous | trees which lose their leaves |
| evergreens | trees which keep their leaves all year round |
| hibernation | when animals become inactive when there is less food available |
| migration | when birds fly to warmer places in winter |
| animals require resources such as | oxygen, space and shelter |
| population | numbers of an organism in a given area |
| food chains show | energy flow |
| food chains can be added | to form food webs |
| top predator | a predator which is not prey |
| carnivore | consumer and predator |
| herbivore | consumer |
| consumers | eats other organisms |
| producers | make their own food |
| plants are | producers |
| prey | food of predators |
| predators | hunt and kill |
| energy flow in a food chain | is shown by an arrow |
| pyramids of number | show the numbers of different organisms at each stage of a food chain |
| pesticides | poisons which kill organisms which cause problems |
| persistent | poisons which are not broken down in nature |
| DDT is | a persistent poison |
| poisons become | more concentrated along a food chain |
| nomads | move from place to place |
