Lecture 3: The Aquatic Environment

Question 1

The aquatic ecosystems cover ___% of the planet make them the ______ _____ habitats

Answer 1

75% most dominate

Question 2

Almost all living phyla of animals evolved in what type of environment

Answer 2

Aquatic

Question 3

water is a ____ molecule

Answer 3

Polar

Question 4

What property allows freshwater organisms to live below the surface of ice formed in the winter?

Answer 4

The fact that water molecules become less dense when moving from a liquid to a solid state, causing ice to raise to the surface

Question 5

High surface tension is caused by what

Answer 5

Strong attraction of water molecules to each other rather than to air

Question 6

Water that is being compressed will exert pressure in what direction

Answer 6

upwards

Question 7

What two forces can operate together to force a moving object in the water to the surface

Answer 7

Bouyncy and viscosity

Question 8

Does the aquatic environment have a high or low microclimate variability

Answer 8

low

Question 9

Aquatic environments are divided by what two things

Answer 9

Depth (Mean ocean depth is 3.7km)
Salinity
- Salt water Oceans - 97%
- Freshwater - 1%

Question 10

75% of the ocean is

Answer 10

3-6 km deep

Question 11

Solar radiation declines with what

Answer 11

depth

Question 12

what are the direct and indirect impacts that are caused by solar radiation declining with depth

Answer 12

Direct: Plants, need solar radiation therefore restricted to top 100m
Indirect: Animals
- herbivores are restricted to the areas where plants reside

Question 13

What adaptations do animals have that inhabit deep water greater than 200m?

Answer 13

Lacking pigment
Large eyes
Organs that produce light
Organisms undergo chemosynthesis

Question 14

Temperature ____ with a greater depth

Answer 14

Declines

Question 15

Thermocline is what

Answer 15

A region where the most rapid temperature change is

Question 16

Hypolimnion is what

Answer 16

The bottom level of the water that results in a very small decline in temperature with depth

Question 17

Thermal stratification occurs in what types of water

Answer 17

All open bodies of water

Question 18

Permanent stratification occurs where and what is the result

Answer 18

Tropics, no mixing

Question 19

Water grows ____ dense as it cools to 4 degrees Celsius , it grows ____ as it cools from 4 to 0

Answer 19

more dense

less dense

Question 20

oxygen diffuses from the atmosphere into what type of environments

Answer 20

Aquatic