Topic 5: On the wild side.

Question 1

Describe an Ecosystem.

Answer 1

All organisms living in a particular area as well as all the non living elements of that particular area.

Question 2

Describe a Community.

Answer 2

All of the populations off all organism living in a particular habitat at a particular time.

Question 3

Describe a population.

Answer 3

All of the organism of a particular species living in a particular habitat at a particular time.

Question 4

Describe a Habitat.

Answer 4

A place where an organism lives.

Question 5

Describe the Niche concept.

Answer 5

States only one organism can occupy each niche in a given habitat at a given time as the better adapted organism will outcompete others.

Question 6

Describe succession.

Answer 6

The change in species inhabiting an area over time.
Brought about by changes in the environment made by the organisms colonising it themselves.

Question 7

Describe Primary succession.

Answer 7

Occurs when an area previously devoid of life is first colonised.

Question 8

Describe Secondary succesion.

Answer 8

Occurs with existing soil that is clear of vegetation. may occur after forest fire.

Question 9

Describe a Pioneer species.

Answer 9

The first organisms to colonise an area are adapted for very harsh conditions.
Reproduce and die decomposing adding humus leading to formation of soil making environment suitable for more complex organisms.

Question 10

Describe a climax community.

Answer 10

The most productive, self-sustaining and stable community that the environment can support, usually with only one or two species.

Question 11

Name the two stages of Photosythesis.

Answer 11

Light dependant reaction:
Cyclic phosphorylation.
Non-cyclic phosphorylation.

Light-independent reaction:
Calvin cycle.

Question 12

State why Some energy is lost at each trophic level.

Answer 12

Undigested matter.
Respiration.
Metabolic waste products like urea.

Question 13

Describe global warming.

Answer 13

Gradual increase in the average temperature of the earths atmosphere and surface.

Question 14

Name the 4 methods of giving evidence for climate change.

Answer 14

Records of carbon dioxide levels.
Temperature records.
Pollen in peat bogs.
Dendrochronology.

Question 15

Describe how records of carbon dioxide levels gives evidence for climate change.

Answer 15

Increasing carbon dioxide concentration in atmosphere is believed to contribute towards climate change as CO2 is a greenhouse gas.

Question 16

Describe how temperature records give evidence for climate change.

Answer 16

enable analysis of increasing temp over the years.

Question 17

Describe how pollen in peat bogs gives evidence for climate change.

Answer 17

Pollen grains are conserved in peat bogs analysis of pollen gives an idea of what kind of plats were present at time peat was formed.

Question 18

Describe how Dendrochronology gives evidence for climate change.

Answer 18

Size of tree rings are effected by temp and humidity.

Question 19

Describe the greenhouse effect.

Answer 19

Short-wavelength UV radiation passes through earths atmosphere and is reflected by earths surface.
Reflected rays have longer wavelengths and are infra red allowing them to be reflected by greenhouse gases further heating the earth.

Question 20

Give the three effects of climate change changing rainfall patterns and seasonal cycles will have.

Answer 20

Changes in distribution of species moving to cooler areas.
Changes to development as many reptiles sex is determined by temp effecting sex ration.
Disrupt life cycles.