Aquatic Ecosystems

Question 1

Why are aquatic systems said to be simpler than terrestrial systems?

Answer 1

They are only made up of water molecules

Question 2

What is the importance of water as a Medium of life?

Answer 2

1. Source of all nutrients for aquatic life
   2 Facilitates distribution of organic and inorganic wastes in aquatic ecosystem
   3.Determines amount of light that reaches aquatic community
   4.The heat properties of water influence the circular patterns in waters therefore affecting aquatic community.

Question 3

What are the three types of aquatic ecosystems?

Question 4

Describe the hydrological cycle and it’s contribution to the movement of matter and nutrients

Question 5

Differentiate between :
(I) Gravitational water
(II) Capillary water
(III) Hygroscopic water

Question 6

Does all water circulate in the hydrological cycle?Explain your answer.

Question 7

What are the 8 wonders of the world?

Answer 7

Great Pyramid of Giza (Egypt), Machu Picchu (Peru), Christ the Redeemer (Brazil), Taj Mahal (India), Colosseum (Italy), Petra (Jordan), Chichen Itza (Mexico) and Great Wall of China

Question 8

Explain 2 processes through which water aids in movement of nutrients.

Answer 8

1. Evapo-transpiration
   - loss of water directly from water surfaces or plant leaves and stems into atmosphere
   - brings minerals close to the surface of the earth in deserts

2.Surface runoff
- mov’t of water from precipitation across the earth’s surface to stream channels or low points on the earth’s surface
- aids in erosion of accumulated sediments
- ecosystems show net gain or loss of specific materials like forests may lose nutrients while swamps gain nutrients
- streams carry rock fragments which are chemically altered through additional weathering to release nutrients that will be utilised by nutrients downstream
- allows weathering of underlying rocks releasing nutrients into ecosystems.

Question 9

What is the importance of water in nutrient cycles?

Answer 9

1. Important constituent of living tissues as liquid water or part of essential molecules
   2.medium by which nutrients are introduced to plants -absorption by roots
   3serve as a means of thermal regulation in plants and animals
   4.medium by which sediments are removed or added in different local ecosystems
   5.covers a great majority of the earth’s surface and is the dominant feature of all aquatic ecosystems

Question 10

What is the importance of water in nutrient cycles?

Answer 10

Important constituent of living tissues as liquid water or part of essential molecules
2.medium by which nutrients are introduced to plants
3serve as a means of thermal regulation innplants and animals
4.medium by which sediments are removed or added in different local ecosystems
5.covers a great majority of the earth’s surface and is the dominant feature of all aquatic ecosystems

Question 11

What resources do organisms need for survival?

Question 12

Explain the relation between nutrient cycles and the first law of thermodynamics

Question 13

Define a limiting factor

Question 14

What are the 3 different kinds of essential elements?Give 3 examples for each.

Question 15

What factors influence biogeochemical cycles?

Answer 15

1. Biology of the organism that will use the element
   2.Geological availability of the element
2. The organic and inorganic chemistry of the element

Question 16

What is a biogeochemical cycle?

Question 17

Describe the phosphorus cycle

Question 18

Describe the nitrogen cycle

Question 19

Describe the carbon cycle

Question 20

Describe sulfur cycle

Question 21

What does water redux potential refer to?

Question 22

Define :
a. Lentic ecosystems
b. Loctic ecosystems
Brackish

Question 23

What factors drive the hydrological cycle?

Question 24

Explain 3 factors that influence :
(i)Evapo-transpiration
(ii)Surface run-off

Question 25

Why do desert plants have deeper roots than most plants?

Question 26

Why does water move along food chains?

Question 27

Describe energy flow in an ecosystem

Question 28

What are the most common limiting factors?

Question 29

Define a wetland

Question 30

Give 5 distinguishing features of a wetland

Question 31

Give 5 examples of floodplains in Kenya

Question 32

Give 3 different types of wetlands in :
(i)Temperate regions
(ii)Tropical regions

Question 33

Give 5 characteristics of soil

Question 34

Give 5 examples of wetlands in Kenya

Question 35

Giving examples, name the three types of vegetation found in lakes

Question 36

Explain 4 possible sources of water for a wetland

Question 37

What are the 2 different type of wetlands found in marine wetland ecosystems?

Question 38

With examples, give 4 adaptations of vegetation found in mangrove wetlands

Question 39

What is the advantage of saline conditions in marine wetland ecosystems?

Question 40

With examples, give characteristics of the following wetlands :
- maine wetlands
- Peatlands
- swamps and marshes
- riparian wetlands

Question 41

Giving examples, differentiate these 2 wetland vegetations :
- Aquatic macrophytes
- Aquatic microphytes