Chapter 3

Question 1

What is natural selection?

Answer 1

Natural selection is the process that makes change possible in living things.

Question 2

What is adaptive radiation?

Answer 2

Adaptive radiation describes the change from a common ancestor into a number of different species that “radiate out” to inhabit different niches.

Question 3

What is the relation between Galapagos finches, natural selection, and adaptive radiation?

Answer 3

The Galapagos finches have branched out into 13 different species. Each species have adapted to a niche on the ground or in the trees and they all eat different types of food.

Question 4

What is ecological succession?

Answer 4

Ecological succession is the changes that take place over time in certain areas.

Question 5

What are the two types of ecological succession?

Answer 5

1) Primary succession

2) Secondary succession

Question 6

What is primary succession? What are the steps of it?

Answer 6

Primary succession occurs in areas without soil.

1) Lichens grow and secrete chemicals that break down rock beginning the formation of soil. Decaying lichens add nutrients to the soil.
2) More plants begin to grow. As they decay, more nutrients is added to the soil.
3) Insects and micro-organisms move into the soil.
4) Grass, flowers, and shrubs begin to grow, attracting animals.
5) Tree seeds are transported by animals, and they begin to grow.
6) Trees, animals, plants live in the area to make up a mature community.

Question 7

What are pioneer species?

Answer 7

Pioneer species are the first organisms to survive and reproduce in an area.

Question 8

What is a mature/climax community?

Answer 8

A mature/climax community is the outcome that occurs in the process of primary succession.

Question 9

What is secondary succession?

Answer 9

secondary succession is a process that occurs after a disturbance to an area that already has soil and once was the home of living organisms.

Question 10

What are 4 large disturbances that greatly affect mature communities?

Answer 10

1) flooding
2) drought
3) tsunamis
4) insect infestations

Question 11

How can flooding affect ecosystems?

Answer 11

Flooding can affect the ecosystem because it may result in soil erosion and soil pollution if toxic chemicals are present in floodwater. It can also cause widespread disease among humans if toxins or harmful bacteria from untreated sewage enter the drinking water supply.

Question 12

How can tsunamis affect ecosystems?

Answer 12

Tsunamis can affect the ecosystem because it has the strength to carry away plants and animals which disrupts habitats and food webs. The large volume of salt water carried onto the shore may change soil composition.

Question 13

How can droughts affect ecosystems?

Answer 13

Droughts can affect the ecosystem because there is not enough water to sustain plants and animals which will destroy habitats.

Question 14

What is an example of insect infestations affecting BC’s ecosystem?

Answer 14

The mountain pine beetles are attacking young and old trees in the BC forest as cold winters are no longer occurring. Due to the impact of these beetles, many birds and mammals have lost their habitat.

Question 15

What is sustainability?

Answer 15

Sustainability refers to the ability of an ecosystem to sustain ecological processes and can also refer to using the resources of an ecosystem without reducing the function of health or the ability of future generations to meet their needs.

Question 16

What is land use?

Answer 16

Land use refers to the way were use the land around us for urban development, agriculture, industry, mining, and forestry.

Question 17

What are resources? Give 6 examples.

Answer 17

Resources are naturally occurring materials.

example; soil, wood, water, gas, oil, minerals

Question 18

What is habitat loss?

Answer 18

Habitat loss refers to the destruction of habitats, usually due to human activity.

Question 19

What is habitat fragmentation?

Answer 19

Habitat fragmentation is the division of habitats into smaller, isolated fragments.

Question 20

What is polyculture? How can it benefit the ecosystem?

Answer 20

Polyculture is a method where plants are mixed in with other plants. Polyculture can benefit plants as the soil becomes cooler, moister, more productive, and increases in nutrients. It can also reduce soil erosion and weed invasion.

Question 21

What is deforestation?

Answer 21

Deforestation is the practice in which forests are cleared for human use and never replanted.

Question 22

What is soil degradation?

Answer 22

Soil degradation is when water and wind erosion removes topsoil from bare land.

Question 23

What is soil compaction and why is it a problem?

Answer 23

Soil compaction occurs when soil particles are squeezed together and the air spaces are reduced. This a problem because compaction reduces the movement of air, water, and soil organisms, all of which are essential to soil health. It can also lead to run-off which adds excess nutrients to bodies of water.

Question 24

How does soil compaction occur?

Answer 24

Grazing farm animals

Farm vehicles

Question 25

What is aeration?

Answer 25

Aeration is when small plugs of soil are mechanically removed to reduce run-off, and improve movement of air and water through soil.

Question 26

What are 3 examples of resource exploitation?

Answer 26

1) harvesting fish and timber
2) mining coal and minerals
3) extracting oil and gas

Question 27

What is contamination?

Answer 27

Contamination is the introduction of chemicals, toxins, wastes, or micro-organisms into the environment in harmful concentrations.

Question 28

What is mine reclamation?

Answer 28

Mine reclamation is the restoration of land and the development of water treatment facilities to remove heavy metals draining from the mine site.

Question 29

What is overexploitation?

Answer 29

Overexploitation is the use or extraction of a resource until it is depleted.

Question 30

What is an example of overexploitation affecting the food web?

Answer 30

Orcas once preyed upon sperm and baleen whales but humans began to over hunt these whales. This led to the orcas finding new prey, such as sea otters. The low population of sea otters resulted in the sea urchins to reproduce rapidly.

Question 31

What is traditional ecological knowledge?

Answer 31

Traditional ecological knowledge it the First Nation’s understanding of plants, animals, and natural occurrences in their forest environments.

Question 32

What are some benefits to spring burning of prairie grasslands and forest fires?

Answer 32

Burning recycles nutrients and increases plant growth. It also reduces forest litter and opens the canopy which allows more plants that require more sunlight on the understorey to grow.

Question 33

What are native species? Give an example.

Answer 33

Native species are plants and animals that naturally inhabit an area.

example; cattails

Question 34

What are introduced species/foreign species?

Answer 34

Introduced species/foreign species are species that are brought to an environment to where they did not exist previously.

example; leaf-feeding beetles

Question 35

What are invasive species? Give an example.

Answer 35

Invasive species are organisms that take over the habitat of native species or invade their bodies, weakening their immune system. They have high reproduction rate, are aggressive competitors, and lack natural predators in their new habitats.

example; purple loosestrife

Question 36

What are 5 ways that introduced species affect native species?

Answer 36

1) competition
2) predation
3) disease
4) parasitism
5) habitat alteration

Question 37

Give an example of how competition affect the native species.

Answer 37

The carpet burweed competes with native plants for habitat. It’s spiny tips easily pierce the skin of animals and campers.

Question 38

Give an example of how predation affects the native species.

Answer 38

Predation affects the native species as native predators may not have adaptations to escape or fight them. Yellow crazy ants have decreased the population of red crabs. They swarm their prey and squirt formic acid at them.

Question 39

Give an example of how disease and parasites affect the native species.

Answer 39

Disease causing viruses and bacteria weaken the immune response of an ecosystem’s native plants and animals. Sea lampreys attaches it’s mouth onto it’s prey and sucks it’s body fluids.

Question 40

Give an example of how habitat alteration affects the native species.

Answer 40

Introduced invasive species can make a natural habitat unsuitable for it’s native species by changing the structure or composition. Wild boars damage the environment by rooting, wallowing, and spreading weeds that interfere with natural succession.

Question 41

What are 6 introduced invasive species in BC?

Answer 41

1) Eurasian milfoil
2) Norway rat
3) American bullfrog
4) European starling
5) Scotch broom
6) Sea lampreys

Question 42

Why is scotch broom one of the toughest invasive species to control?

Answer 42

Scotch brooms produce up to 18 000 seeds per plant. It’s yellow flowers attract bees for pollination and is well adapted for surviving drought. It also fixes nitrogen into the soil adding an excess amount which interferes with native species.