Ecology

Question 1

Levels of organization in ecology

Answer 1

Cell, Tissue, Organ, Organism, Population, Community, Ecosystem, Biome, Biosphere.

Question 2

What is population?

Answer 2

1. A group of individuals in a particular area that interbreed and therefore share the same gene pool.
2. Like a subset of a species, will interbreed due to close location.
3. Evolution is seen at this level as individuals and their offspring have changing genotypes and phenotypes.

Question 3

Exponential growth

Answer 3

Growth occurs exponentially until it can no longer sustain that rate, and it stabilizes.

Question 4

Carrying capacity

Answer 4

Max population size an environment can sustain. Can change if an environment changes (damaged food source, etc). Predators affect the carrying capacity of an environment.

Question 5

What is a community?

Answer 5

Group of populations that live in a particular environment. Members of the same community are members of the same ecosystem.

Question 6

Niche

Answer 6

The way an organism lives in its environment (type of food it eats, where it hunts).If 2 populations have the same niche, there will be a lot of competition, and the losing population will usually evolve to survive.

Question 7

Predation

Answer 7

When one organism eats another. The organism eating is the predator, but the organism that is eaten doesn’t always die. For example, leaves.

Question 8

Coevolution

Answer 8

The prey evolves to escape the predator, then the predator evolves to better hunt the prey.

Question 9

The food chain

Answer 9

1. Starts with primary producers. Photosynthetic, usually plants. Highest amount of species here.
2. Primary consumers- herbivores that eat the primary producers.
3. Secondary consumers- omnivores
4. Tertiary consumers- carnivores

Question 10

Decomposers

Answer 10

Break down dead bodies. Bacteria and fungi.

Question 11

Scavengers

Answer 11

Eat the waste and remains of dead organisms. Vultures, worms.

Question 12

How does a food web work?

Answer 12

Arrows show who feeds who.

Question 13

The 10% rule

Answer 13

There is more energy available at the bottom of the pyramid than at the top. Only 10% of energy is transferred from one level to the next, because most of the energy is used to power the prey.

Question 14

Ecological Succession

Answer 14

Gradual change in a community over time. Each new community coexists with the previous one. Lichen is first to colonize barren rock. The final community would be deciduous trees.

Question 15

Pioneer organisms

Answer 15

First to arrive in the area. Other organisms arrive as they are attracted by the first.

Question 16

Climax community

Answer 16

Permanent group that is the last to arrive. Shows that succession is finished.

Question 17

How is ecological succession different from evolution?

Answer 17

Time frame is shorter, and it consists of continuous change with predictable changes.

Question 18

Ecosystem

Answer 18

A community together with the environment it lives in.

Question 19

The water cycle

Answer 19

1. Recycles water
2. Water is taken into clouds by evaporation and transpiration (water escaping from leaves). It returns to bodies of water through precipitation, and from the soil to the ocean through runoff.

Question 20

The carbon cycle

Answer 20

1. Carbon is mostly found as carbon dioxide in the atmosphere
2. Is used by plants to form organic molecules (sugars) which are then eaten by animals.
3. The carbon is recycled to the atmosphere by respiration.

Question 21

The nitrogen cycle

Answer 21

1. Most nitrogen is taken from the soil by plants as nitrate and incorporated into protein
2. The proteins are consumed by animals and recycled to the soil when the animals die.

Question 22

What is a biome?

Answer 22

Large areas classified by the ecosystems they contain.

Question 23

Fauna

Answer 23

Animal life

Question 24

Flora

Answer 24

Plant life

Question 25

Biosphere

Answer 25

All biomes together (planet Earth).

Question 26

Terrestrial Biomes

Answer 26

1. The Tundra- frozen topsoil, some shrubs, a few mammals such as wolves. 2. The Taiga- contains many evergreen trees. Moose, bears, wolves. 3. Deciduous Forests- lots of rain, hot and cold seasons, trees that drop leaves in winter. Deer, foxes 4. Grasslands/savanna- scattered trees limited by drought. Tropical- zebras, kangaroo, Temperate- horses, bison. 5. Tropical Rain Forests- high rain fall, tall trees, many plants, birds, monkeys, lizards 6. The Desert- very dry. Cacti, birds, lizards, small rodents

Question 27

Marine Aquatic Biomes

Answer 27

1. Interdial Zone- where land and water meet, periods of submersion with tides. Clams, crabs. 2. Neritic Zone- from shore to edge of continental shelf. Kelp, seaweed, reefs in warm water 3. Oceanic Zone- open water, marine mammals. Divided into open water (pelagic) and ocean bottom (benthic) zones.

Question 28

Freshwater Aquatic Biomes

Answer 28

1. Littoral Zone- shore of a lake, many plants, insects, snails. 2. Limnetic Zone- extends downward as far as light will penetrate. Photosynthetic organisms and primary consumers. 3. Profundal Zone- aphotic region. Nutrients float down to support primary consumers, which support secondary consumers.

Question 29

Aphotic Region

Answer 29

No light at all.

Question 30

Greenhouse effect

Answer 30

1. Increased concentrations of carbon dioxide through burning fossil fuels causes increased temperatures. 2. Effects- flooding, changes in plant and animal populations, detrimental changes in agriculture, changes in precipitation patterns.

Question 31

Ozone depletion

Answer 31

1. Chemical pollution causes depletion of the atmospheric ozone layer, which protects Earth from UV radiation. 2. Effects- genetic effects, increased incidence of cancer

Question 32

Acid rain

Answer 32

1. Burning of fossil fuels produces pollutants such as sulfur dioxide and nitrogen dioxide, which react with water droplets in clouds. 2. Effects- lowers pH of aquatic ecosystems and soil, damaging water systems, plants, and soil.

Question 33

Desertification

Answer 33

1. Lands overgrazed by animals creates deserts from grasslands 2. Effects- reduces available habitat for organisms

Question 34

Deforestation

Answer 34

1. When forests are cleared, especially by slash and burn method. 2. Effects- erosion, floods, changes in weather patterns

Question 35

Pollution

Answer 35

Toxic chemicals such as DDT resist breakdown and are found in tissues of living organisms. As each tropic levels consumes DDT, it becomes more concentrated (biomagnification).

Question 36

Reduction in biodiversity

Answer 36

Plants and animals become extinct as habitats are destroyed. Some of these plants could have medical benefits.

Question 37

Benthic zone

Answer 37

Ocean floor

Question 38

What is an independent variable?

Answer 38

The one being manipulated.