Ecosystems

Question 1

what is ecology?

Answer 1

the name given to the study of the relationships between organisms and their environments.

Question 2

what is an ecosystem?

Answer 2

the dynamic interaction between living and non-living factors in a given area.

Question 3

can ecosystems vary dramatically in size?

Answer 3

yes.

Question 4

what determines the boundaries of a particular ecosystem being studied?

Answer 4

the person or team carrying out the study.

Question 5

are all ecosystems dynamic?

Answer 5

yes.

Question 6

what does it mean for an ecosystem to be dynamic?

Answer 6

they are consantly changing.

Question 7

what are the two different types of factors that affect an ecosystem?

Answer 7

• biotic factors.
• abiotic factors.

Question 8

what are biotic factors?

Answer 8

living factors.

Question 9

what are abiotic factors?

Answer 9

non-living (physical) factors.

Question 10

what are some examples of biotic factors?

Answer 10

• organic matter
• jellyfish
• phytoplankton.

Question 11

what are some examples of abiotic factors?

Answer 11

• light availability
• temperature
• water availability
• oxygen availability
• edaphic (soil factors).

Question 12

what might animals compete for?

Answer 12

• food
• territory
• breeding partners.

Question 13

why is light important for some organisms?

Answer 13

plants require light for photosynthesis. the greater the availability of sunlight, the greater the success of a plant species.

Question 14

how do plants cope with different light intensities?

Answer 14

• in areas of low light they may have larger leaves.
• may develop photosynthetic pigments that require less light.
• may develop reproductive systems that operate only when light availability is at an optimum.

Question 15

what effect does temperature have on an ecosystem?

Answer 15

temperatures effect the enzymes controlling metabolic reactions

Question 16

why are warmer temperatures often good for organisms?

Answer 16

plants and ectotherms develop more rapidly in warmer temperatures.

Question 17

how might a change in temperature trigger an animal?

Answer 17

• migration
• hibernation

Question 18

how might a change in temperature trigger a plant?

Answer 18

• leaf-fall
• dormancy
• flowering

Question 19

what does a lack of water lead to?

Answer 19

water stress, maybe death.

Question 20

what does a lack of water mean for plants?

Answer 20

a lack of water may lead a plant to wilt as water is required to keep cells turgid and keep the plant upright.

Question 21

why is water availability important for plants?

Answer 21

• water is required for photosynthesis.
• water is required to keep cells turgid to keep the plant upright.

Question 22

does cold or warm water contain high concentrations of oxygen?

Answer 22

cold.

Question 23

why is it beneficial to have fast flowing cold water in an aquatic ecosystem?

Answer 23

cold water contains higher concentrations of oxygen. If the water becomes too warm or the flow rate becomes too slow, the resulting drop in oxygen concentration can lead to the suffocation of aquatic organisms.

Question 24

why is waterlogged soil bad for plants?

Answer 24

the air spaces between the soil particles are filled with water so there is less oxygen availabilty for plants.

Question 25

what are the three main soil types?

Answer 25

• clay
• loam
• sandy

Question 26

what are the characteristics of clay soil?

Answer 26

• fine particles
• easily waterlogged
• forms clumps when wet.

Question 27

what are the characteristics of loam soil?

Answer 27

• different sized particles
• retains water but does not become waterlogged.

Question 28

what are the characteristics of sandy soil?

Answer 28

• coarse, well seperated particles that allow free draining.
• does not retain water so is easily eroded.