Biology Unit 1 topic 4

Adaptations

Adaptations help organisms survive in the habit.

Organisms compete with each other for limited resources which includes water and space.

Plants also compete with each other for lights and minerals.

Ecological words

Environment- all the conditions that surround living organism

Habitat- the place where organism lives

Population- the amount of a single species that live in habit

Community- all the populations of different organisms that live in habitat

Ecosystem- community and its habitat

Competition

Organisms will die if they are unsuccessful in competing for resources

Resources that animal compete include water, food and space

Plants compete for water space and mineral salts

Cold climates

Plants in the Arctic grows very close to the ground and have small leaves this helps them to conserve water

Polar bears are adapted for survival in the Arctic they have white fur as camouflage from prey

They have a thick layer of fat and fur for insulation

They have a small surface area to volume ratio which minimises heat loss

Hot climates

Camels have large flat feet to spread their weight on the sand

They have thick fur on the top of the body for shade and thin fur elsewhere to allow easy heat loss 

A larger surface area to volume ratio which maximises heat loss

They have the ability to go for a long time without water

Desert plants

Cacti has to stems that can store water

Widespread root systems that can collect water from a large area.

Cacti have spines instead of leaves.  These minimise the surface area and reduce water loss by transpiration.  The spines also protect the cacti from animals that might eat them.

Extremophiles

They are organisms that live in very extreme environments which would kill most other organisms

Extreme conditions include

High temperature

High concentrations of salt in the water

High pressures.

Environmental Changes
Changes in the environment may affect distribution and behaviour of organisms.

Changes can be cause by living factors e.g. change in a predator, food source or a competitor, or non living factors e.g. change in temperature or rainfall.

If prey population grows predator numbers will increase as there is an increase in food supply.
Growing predator numbers will reduce the number of food supply so it can no longer sustain the predator population and number of predator goes down.

Indicators of pollution
Most common source of air pollution is the burning of fossil fuels. Lichens can be used as air pollution indicators.
Lichens are plants that grow on places such as rocks or tree bark.
They are very good at absorbing water and nutrient to grow.
Air pollutant dissolved in rainwater make it more acidic and damages lichens preventing them from growing.
Bushy lichens need really clean air
Leafy lichens can survive a small amount of pollution
crusty lichens can survive in more polluted air

Water pollution is caused by discharge of harmful substances into river, lakes and seas.
Many aquatic invertebrate animals cannot survive in polluted water so their numbers can indicate how polluted the water is.
Clean- mayfly larva
Low- fresh water shrimp
high- water louse
Very high- rat tailed maggot, sludge worm

We can measure rainfall using a rain gauge. Depth of rain is measured  consistently.
Temperature can be measured using a normal thermometer.