Topic 3

Question 1

Aquatic ecosystems cover __ of the planet making them the most dominant habitats

Answer 1

75%

Question 2

All living things contain what percentage of water

Answer 2

75-95%

Question 3

Water is a ..

Answer 3

polar molecule that acts as universal solvent

Question 4

Water molecules become less dense when..

Answer 4

moving from a liquid to a solid state

Question 5

Cohesion resists ..

Answer 5

external forces that would break its bonds.

Question 6

Cohesion is..

Answer 6

high surface tension caused by stronger attraction of water molecules to each other rather than air

Question 7

High viscosity

Answer 7

streamlined adaptions present i in many aquatic organisms. flotation within the water column

Question 8

Aquatic environments have a low..

Answer 8

microclimate variability

Question 9

Mean ocean depth

Answer 9

3.7 km

Question 10

Ocean is divided by

Answer 10

salinity (fresh water and salt water)

Question 11

Ocean salinity affected by

Answer 11

evaporation and precipitation (generally high salinity at equator than poles)

Question 12

Fresh water environments are divided by

Answer 12

pH

Question 13

Each unit of pH is..

Answer 13

10 fold increase in concentration of H

Question 14

High solute concentration ..

Answer 14

buffers the pH of water in the oceans

Question 15

75% of the ocean is how deep

Answer 15

3-6 km

Question 16

Solar radiation is

Answer 16

• reflected back into atmosphere
• absorbed or reflected by suspended particles
• absorbed by water

Question 17

Solar radiation declines exponentially with..

Answer 17

depth

Question 18

Plants require sunlight for

Answer 18

photosynthesis (restricted to top 100m)

Question 19

Animals inhabiting deep water (>200 m) have adaptations

Answer 19

• lack pigment
• large eyes
• organs that produce light
• chemosynthesis

Question 20

Decline in temperature with ..

Answer 20

depth

Question 21

Thermocline

Answer 21

region with most rapid decline in temp

Question 22

Some form of thermal stratification occurs in

Answer 22

all open bodies of water

Question 23

Mixing of water column can

Answer 23

break down the thermal gradient

Question 24

Fall turn over for temperature in water

Answer 24

surface temp cool and wind action allows mixing between layer (stratification ends) important for nutrient and oxygen dynamics

Question 25

Winter ends the temp turnover because

Answer 25

the surface freezes and deeper water becomes warmest

Question 26

Where does permanent temp stratification occur

Answer 26

tropics

Question 27

Oxygen diffuses from..

Answer 27

the atmosphere and into aquatic environments

Question 28

Oxygen is produced by ..

Answer 28

plants during photosynthesis

Question 29

Photosynthesis restricts

Answer 29

high concentrations of oxygen to surface water

Question 30

Difficulties organisms face in an aquatic environment

Answer 30

• access to light, oxygen and nutrients
• constant osmotic pressure
• low variability in microclimate

Question 31

Buoyancy

Answer 31

When an object’s specific density is lower than the fluid medium in which it sits it will float to the surface

Question 32

Density =

Answer 32

mass/volume

Question 33

Viscosity

Answer 33

A fluid medium’s resistance to flow (ie. fluid friction). Water being forced downwardswill exert pressure upwards

Question 34

Viscosity and Buoyancy can operate together to ..

Answer 34

force a moving object in the water closer to the surface (float)