Environment, evolution and inheritance

Photosynthesis Plants make oxygen by photosynthesis They take in carbon dioxide They use the sunlight to make glucose (sugar) and oxygen When plants decay, the carbon dioxide in them goes back into the atmosphere

Adaptations Animals are adapted to the environments that they live in. For instance, a polar bear lives in the cold Arctic. They have large feet to spread their weight out and stop them sinking in the snow They have thick fur to keep warm and for camouflage

Food chains The plant at the start of a food chain is called a producer The arrows show the way the energy flows, and what eats what

Competition Plants compete for water, space, light and nutrients They are affected by non-living environmental factors like a rise in average temperature They are affected by living environmental factors like being trampled on by humans

Pollution Burning fossil fuels often releases sulfur dioxide into the atmosphere. This gas dissolves in water and forms acid rain. Humans also affect the environment by making waste and using up resources

Natural selection This helps us understand how some animals survive while others die. Dark peppered moths are more common in smoky cities because they are better camouflaged. This means they don’t get eaten so they can breed more (next slide for images)

The dark tree is in a smoky city The dark tree is in a smoky city. The light tree is in the clean countryside

Reproduction There are two types of reproduction When male and female sex cells join together, this is sexual reproduction When only one parent is needed, this is asexual reproduction. Offspring identical to their parents are called clones. Genes (smallest) make up chromosomes which are in the nucleus of a cell (largest)