Biology : B7

Describe the water cycle

1. Energy from the sun causes water (from the land sea) to evaporate into water vapour. Water also evaporates from plants - transpiration.

2. The warm water vapour is carried upward and cools and condenses to form clouds.

3. Once the water droplets get too big, they are released through precipitation (rain, hail, snow and sleet) and are released to the ground.

4. The cycle repeats over and over.

Why do plants and animals need water?

For all chemical reactions in the body and for photosynthesis (plants).

How is water returned to the cycle?

From an animal through excretion (sweating and peeing)

From plants through transpiration

Define extremophile

Organisms adapted to live in extreme conditions

Define producers

Organisms which make glucose through photosynthesis (plants).

Define primary consumer

Organisms which eat producers (herbivores)

Define secondary consumer

Organisms which eat the primary consumer (carnivore)

What happens to the energy at each tropic level (stage of the food chain)?

Some biomas (stored energy) is lost through uneaten parts, waste products and heat.

What is the formula to estimate populations using quadrants?

Field area/quadrant area x mean number of organisms per quadrant

How do you carry out a quadrant practical?

1. You need a measuring tape and quadrant

2. Measure and calculate the area of then field and divide into equal squares.

3. Assign each square which a number.

4. Use a random number generator and count the number of organisms in each square.

5. Do this 10 times and calculate the mean number of organisms per quadrant.

6. Multiply the mean number of organisms per quadrant by the number of times bigger the area is than the quadrant.

Explain the 5 ways ecosystems are maintained?

1. Reintroducing hedgerows and field margins in field to produce a habitat.

2. Government programs to reduce deforestation and carbon emissions.

3. Recycling reduces the amount of land used for landfill.

4. Habitat protection e.g. conserving wetlands to protect habitats.

5. Breeding programs set up by zoos to breed endangered species.

How is the cactus adapted?

Spikes - prevents it from being eaten.

Thick and waxy outer layer - reduces water loss.

Large, fleshy stems = to store water.

Long, strong roots = maximise absorption of underground water.

How is the camel adapted?

Leather like mouth - allows it to eat spikey plants.

Long eyelashes and thin nostrils - avoid blowing sand and injury.

Sandy colour = camouflage.

Large SA:V ratio - helps to lose heat.

Stores fat - insulates to cool down.

Large and flat feet - to walk on sand.

Don’t sweat - reduce water loss.

How is the polar bear adapted?

Thick fur and layers of fat - retain heat in cold environments

White fur - camouflage to hunt prey

Sharp teeth and claws - easily tear and rip food.

Small SA:V ratio - retains heat

Large feet - avoid sinking into snow

Strong muscles - run fast and rip food.

Define deforestation

The cutting down of tress for human use.

Why do we deforest land?

• Agriculture

• Quarrying

• Buildings and urbanisation

• Landfill

What problems does deforestation cause?

• Less carbon dioxide is taken in by trees through photosynthesis.

• Less biodiversity as habitats are destroyed.

• More carbon dioxide is released as trees are burnt.

• Microbes respire on dead wood releasing carbon dioxide.

What are peat blogs?

Peat blogs are acidic and waterlogged.

They are made up of carbon.

Peat is used for soil and fuel.

Plants in a peat blog do not decay as there is little oxygen within.

Destroying peat blogs releases carbon dioxide as microbes can respire on decaying plants.

What do animals compete for?

Food, territory and mates.

What do plants compete for?

Light, space, water and minerals.

What is a cyclic pattern?

When the rise and falls of predator/prey populations correspond with the prey/predator population.

They are co-dependent.

Define adaption

How an organism is suited to survive in its habitat.

What are 3 types of adaptation?

Structural: features of the body e.g. shape and colour.

Behavioural: the way an organism behaves.

Functional: things to do with the body e.g. reproduction or metabolism.

Describe the carbon cycle within the environment

• Plants take in carbon dioxide through photosynthesis and store it as starch.

• Animals consume the plants eating the starch.

• These animals respire further releasing carbon dioxide.

• When these animals die carbon is released as they decompose.

• Decaying matter is fed on by microbes which respire.

• Dead organisms form fossil fuels releasing carbon when combusted.

Where is carbon found?

In all living organisms.

Where does decay happen fastest?

In moist, warm and aerobic conditions.

What processes are part of the carbon cycle and do they release or take in carbon?

Respiration: carbon dioxide is released. All animals respire.

Photosynthesis: carbon dioxide is taken in. Done by all plants.

Combustion: burning of fuel, carbon dioxide is released.

Decombustion: carbon dioxide is released by decaying matter and microbes respire from feeding on decaying matter, releasing carbon dioxide.

What is the word equation for photosynthesis?

Carbon dioxide + water = glucose + oxygen

What is the word equation for respiration?

Glucose + oxygen = carbon dioxide + water

What are the 4 effects of global warming?

1. Less biodiversity = species can not survive the changes to their climate.

2. Changes in migration patterns = areas get warmer e.g. birds have to move further north.

3. Flooding = higher temperatures cause glaciers to melt which rises sea levels.

4. Changes in species distribution = animals have to keep moving due to changing temperatures.

Define habitat.

Where an organism lives.

Define population.

All the organisms of one species living in a habitat.

Define community.

The populations of different species living in a habitat.

Define ecosystem.

The interaction of the community of biotic organisms with abiotic parts of the environment.

Define biodiversity.

The variety of different species within a habitat.

Define a transect.

Transects show the population distribution along a line and how the population varies.

How do you carry out a transect experiment?

1. Mark out a line in the area you want to study using a measuring tape.

2. Place a quadrant against the line and count the organisms in it.

3. Move the quadrant along the line in regular intervals and count the organisms.

What are the 3 types of pollution and what are they caused by?

Water pollution = sewage and toxic chemicals such as fertilisers enter the water and kill minerals and organisms.

Air pollution = smoke and acidic gases released into the atmosphere.

Land pollution = household waste in landfill sites, pesticides and herbicides kill plants in farming.

Define greenhouse effect.

When gases in the Earth’s atmosphere stop heat radiating into space.

Define global warming.

The increase in the average temperature over time.

Define climate change.

Long-term changes in the planets weather patterns or average tempratures.

Explain the greenhouse effect.

1. The sun gives out short-infrared wavelength radiation.

2. The radiation is reflected back on Earth as long thermal wavelength radiation which is absorbed by greenhouse gases.

3. Greenhouse gases give out radiation in all directions.

4. Some radiation heads back toward Earth and warms up the surface.

Define abiotic and biotic.

Abiotic = non-living

Biotic = living

What abiotic factors impact an ecosystem?

• Moisture

• Temperature

• Light

• Carbon dioxide levels

• Oxygen levels

• Soil pH

• Mineral content

What biotic factors impact an ecosystem?

• Competition

• (New) predators

• Lack of food

• New pathogens (disease)