Topic 9- Ecosystems And Material Cycles

Question 1

Abiotic factor

Answer 1

Non- living conditions which can influence where plants and animals live./ the distribution of organisms

Question 2

Abiotic factors examples

Answer 2

Sunlight
Wind
Temperature

Question 3

Biomass pyramid

Answer 3

Producer at the bottom, consumer at the top

Size of trophic level depends on mass

Question 4

How is energy lost between each trophic level

Answer 4

The organism could lose energy before it’s eaten (by running)
The organism secretes waste
Not all of the organism is eaten (bones).

Question 5

Population

Answer 5

Group of organisms that are of the same species

Question 6

Community

Answer 6

Different populations interacting with each other

Question 7

Habitat

Answer 7

Where the organisms live. Environment and organisms affect habitat.

Question 8

Interdependence

Answer 8

Organisms within a population and in different populations rely on each other for resources (mating within a population)
(Food different populations)

Question 9

Abundance

Answer 9

A measure of how common something is in an area (it’s population size)

Question 10

How to estimate population size

How to calculate population size

Answer 10

By taking samples using a quadrat which is placed randomly in the area multiple time (and a mean is calculated).

Population size= number of organisms in all quadrats times (total size of area where an organism lives) over (total area of quadrats)

Question 11

Name the types of animals in a food web in order.

Answer 11

Producer 
Primary consumer/ herbivore
Secondary consumer/ carnivore/ predator 
Tertiary consumer/ carnivore/ predator
Top predator

Question 12

How does a belt transect work

Answer 12

Used to measure the effect of abiotic factors on the distribution of organisms.
Quadrats are placed along a line in a habitat and the abundance (population) of organisms is measured as well as the abiotic factors in each quadrat position.
Changes in abundance show which abiotic factor has the greatest effect on an organism.

Question 13

What are pollutants?

What are results in human pollutants?

Answer 13

Substances that can cause harm in the environment.

These can poison or cause harm to organisms (plastic bags being eaten by fish)

Question 14

Biotic factors

Answer 14

Organisms in an ecosystem that affect other organisms

Question 15

Example of biotic factors

Answer 15

In Yellowstone park, grey wolves were the main predator of elk until they died out. This lead to an increase in the number of elk and therefore the overgrazing of many tree species. This lead to a decrease in other herbivores who didn’t have enough food. The number of coyotes increased because there was less competition from wolves for elk.

When wolves were reintroduced it reduced the numbers of elk which increased the numbers of other herbivores (beavers). The beavers built dams creating large pools which allowed new species to grow which increased biodiversity.

Question 16

Parasitism

Answer 16

A feeding relationship in which one organism (parasite) benefits by feeding off a host organism, causing harm to the host. The parasite lives in or on a host.

Question 17

How are tape worms adapted

Answer 17

Hookers and suckers attach worms head to the hosts intestine wall.
Segments contain male and female sex organs so fertilisation can occur.
Flattened body allows absorption of nutrients over whole surface without need for digestive or circulatory systems.

Question 18

How are lice adapted

Answer 18

Sharp mouthparts pierce skin and suck blood.
Sharp claws grip onto hair and skin.
Eggs are glued to hairs to prevent them falling off.

Question 19

Mutualistic relationships

Answer 19

When organisms that live together both benefit from the relationship.
E.g. flowers need insects for pollination.
Insects need flowers for nectar used for food.

Question 20

Eg. Mutualistic relationship

Answer 20

Coral polyps form relationship with single celled algae. The algae can live in the water surrounding corals but are protected inside a polyp. The algae photosynthesise and share food they make with the coral.

Question 21

Eutrophication

Answer 21

Addition of more nutrients to an ecosystem than it normally has.
E.g. too much fertiliser added to a field. Fertiliser helps crops grow but also increase growth of other plants and algae.

Question 22

Steps of how eutrophication can affect an ecosystem

Answer 22

Fertiliser added
Rain washes fertiliser off + nitrates and phosphates dissolve in water.
Nitrates and phosphates not taken up by plants washed into stream.
The high concentrations of nitrates and phosphates in water encourage algae to grow rapidly.
Surface plants block sunlight so plants in water die + stop producing oxygen.
Bacteria that break down dead materials increase and use up oxygen. So concentration of oxygen in the water decreases.

Question 23

Water cycle steps

Answer 23

Rivers flow into lakes + eventually the water returns to ocean.
Groundwater (water that moves through soil and rock).
As air rises it cools, so water vapour in it condenses to form clouds.
As water droplets get too heavy + large they fall as rain or snow.

Question 24

Desalination

E.g.

Answer 24

Obtaining fresh water from sea or salty water. (Distillation- water evaporates + condenses + collected)

Question 25

How is efficiency of energy transfer calculated?

Answer 25

Biomass at higher trophic level (divided by) energy at lower level (times) 100%