Ecosystems

Question 1

Ecology:

Answer 1

Study of relationships between organisms and their environment

Question 2

Ecosystems:

Answer 2

• Made up of all the living organisms that interact with one another in a defined area and the physical factors present in that region

Question 3

How are the boundaries of an ecosystem determined?

Answer 3

• By the particular study that is being carried out
• Not set points

Question 4

Dynamic:

Answer 4

Constantly changing

Question 5

Biotic factors (examples)

Answer 5

• Presence of shrews, hedgehogs
• Size of populations
• Competition between two animal populations for a food source

Question 6

Abiotic factors (non-living or physical)

Answer 6

• Amount of rainfall received
• The yearly temperature range of the ecosystem

Question 7

Biotic factors (definition)

Answer 7

• Interactions between organisms that are living or that have once lived

Question 8

What do animals compete for?

Answer 8

• Food
• Space (territory)
• Breeding partners

Question 9

Abiotic factors list:

Answer 9

• Light
• Temperature
• Water availability
• Oxygen availability
• Edaphic (soil) factors

Question 10

Edaphic (soil) factors:

Answer 10

• Different soil types have different size particles
• This effects the type of organisms that are able to survive in soil

Question 11

Clay:

Answer 11

• Fine particles
• Easily waterlogged
• Forms clumps when wet

Question 12

Loam:

Answer 12

• Different sized particles
• Retains water but doesn’t become waterlogged

Question 13

Sandy:

Answer 13

• Coarse, well-separated particles that allow free draining
• Sandy soil does not retain water and is easily eroded

Question 14

Oxygen availability reduced?

Answer 14

• Waterlogged soil
• Air spaces between soil particles are filled with water
• If water becomes too warm / rate of flow too slow, suffocation of aquatic organisms

Question 15

Oxygen availability increases?

Answer 15

• Fast-flowing water in aquatic ecosystems contains high concentrations of oxygen.

Question 16

Water availability?

Answer 16

• Lack of water leads to water stress / death
• Plants –> wilt as cells aren’t turgid, water required for photosynthesis
• Xerophytes have developed strategies of coping with water stress

Question 17

Temperature:

Answer 17

• Greatest effect on enzyme controlled metabolic reactions
• Ectothermic animals and plants develop more rapidly in warmer temperatures
• Season changes can trigger migration, hibernation, trigger leaf-fall, dormancy, flowering

Question 18

Light:

Answer 18

• Required for photosynthesis
• Greater light availability, greater success of plant species
• Low light areas –> plants have larger leaves, photosynthesis pigments that require less light, reproductive systems that only operate when light availability high