Chapter 3 Ecology

Question 1

Biosphere

Answer 1

consists of all life on earth and all parts of earth where life exists

Question 2

Species

Answer 2

a group of similar organisms that can breed and produce fertile offspring

Question 3

Population

Answer 3

a group of individuals that belong to the same species and live in the same area

Question 4

Community

Answer 4

an assemblage of different populations that live together in a defined area

Question 5

Ecosystem

Answer 5

all the organisms that live in a place, together with their physical environment

Question 6

Biome

Answer 6

a group of ecosystems that share similar climates and typical organisms

Question 7

Biotic Factor

Answer 7

any living part of the environment with which an individual might interact, inluding animals, plants, mushrooms, and bacteria

Question 8

Abiotic Factors

Answer 8

any nonliving part of the environment, such as sunlight, heat, precipitation, humidity, wind or water currents, and soil type

Question 9

What is ecology?

Answer 9

the scientific study of interactions among organisms and between organisms and their physical environment

Question 10

What methods are used in ecological studies?

Answer 10

1) Observation2) Experimentation3) Modeling

Question 11

What is an autotroph?

Answer 11

organisms that use solar or chemical energy to produce “food” by assembling inorganic compounds into complex organic molecules. (store energy in forms that make it available to other organisms that eat them)

Question 12

What is a Primary Producer?

Answer 12

Autotrophs that store energy in forms that make it available to other organisms that eat them. The first producers of energy-rich compounds that are later used by other organisms.

Question 13

Explain photosynthesis

Answer 13

most common in primary producers. Captures light energy and uses it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugar and starches.

Question 14

What is chemosynthesis?

Answer 14

Light-independant organisms that use chemical energy to produce carbohydrates.

Question 15

What is a heterotroph?

Answer 15

organisms that acquire energy from other organisms by ingestion

Question 16

What is a consumer?

Answer 16

organisms that rely on other organisms for energy and nutrients

Question 17

What are the 6 main types of consumers?

Answer 17

all heterotrophs, either primary or secondary1) Herbivores- eat plants2) Carnivores- kill and eat other animals3) Omnivores- variety of food including plants and animals4) Decomposers- “feed” by chemically breaking down organic matter5) Scavengers- consume carcasses of other animals6) Detritivores- eat detritus particles and the decomposers that live on them

Question 18

What is a food chain?

Answer 18

a series of steps in which organisms transfer energy by eating and being eaten

Question 19

What are phytoplankton?

Answer 19

mixture of floating algae which are aquatic primary producers

Question 20

What are zooplankton?

Answer 20

diverse group of small, swimming animals that feed on marine algae (example= krill)

Question 21

What is a trophic level?

Answer 21

each step in a food chain or food web

Question 22

What is an ecologic pyramid? (what are 3 types?)

Answer 22

shows the relative amount of energy or matter contained within each trophic level in a given food chain or food web. 3 types include:1) pyramid of energy (relative energy available at each trophic level)2) pyramids of biomass (grams of organic matter/unit area at each trophic level)3) pyramids of numbers (relative # of individual organisms at each trophic level)

Question 23

What is biomass?

Answer 23

The total amount of living tissue within a given trophic level. Measured in (grams of organic matter/unit area)

Question 24

What is a biogeochemical cycle?

Answer 24

the passing of elements from one organism to the other among parts in the biosphere through closed loops which are powered by the flow of energy

Question 25

What is a nutrient?

Answer 25

chemical substances that an organism needs to sustain life.

Question 26

Which three pathways/cycles are vitally important for life?

Answer 26

1) Carbon cycle2) Nitrogen cycle3) Phosphorus cycle

Question 27

Describe nitrogen fixation and how it can supply us with nitrogen.

Answer 27

changing an nitrogen in the environment into ammonia by bacteria. Soil bacteria convert to nitrates or nitrites. Once these forms of nitrogen are available, primary producers can use them to make proteins and nucleic acids. We can then consume those plants or even the animals which eat those plants. (or even the animals which eat the animals, which eat the animals which feed on the plants)

Question 28

What is denitrification?

Answer 28

when nitrogen is released back into the atmosphere from a fixed chemical location. For example, some soil bacteria convert nitrates into nitrogen gas which releases back into the atmosphere

Question 29

What is a limiting nutrient?

Answer 29

the nutrient whose supply limits productivity. If ample sunlight and water are available, the primary productivity of an ecosystem may be limited by the availability of nutrients.

Question 30

Name the 3 main types of feeding relationships.

Answer 30

1) Producer - Consumer2) Predator - Prey3) Parasite - Host

Question 31

What is an omnivore? (name 1 example)

Answer 31

consumer that eats both plants and animalsexamples: bears and humans

Question 32

What is a carnivore?

Answer 32

Consumers that eat meat. Examples include both predators and scavengers

Question 33

True or False, Predators and prey undergo coevolution.

Answer 33

True- Both evolve based on the other organisms phenotypic characteristics

Question 34

What are the 3 types of symbiosis?

Answer 34

1) Commensalism - 1 species benefit, other is neutral2) Parasitism - 1 species benefit, other is harmed3) Mutualism- Both species benefit

Question 35

As you move up the food chain/web, energy/biomass goes _________

Answer 35

Down- energy and biomass decreases at each trophic level

Question 36

Carbon cycles through a system primarily by the means of what two processes?

Answer 36

photosynthesis and cellular respiration

Question 37

The atmosphere is mostly composed of which gas?

Answer 37

Nitrogen gas (diatomic N2) 78-80% of air

Question 38

What must be done to atmospheric Nitrogen before it can be used by organisms?

Answer 38

bacteria (or some industrial processes) must convert N2 into ammoniumN2 –> NH4+

Question 39

Where do nitrogen fixing bacteria live?

Answer 39

some live in soil, some live on the root tips of plants like the symbiotic bean bacteria, some cyanobacteria live in semi-aquatic ecosystems

Question 40

How do toxins propagate throught the food pyramid/web?

Answer 40

Toxins become amplified as you move up each trophic level