Question 1

What are ecosystems?

Accepted Answer

A biological community of organisms that interact with each other and their physical environment

Question 2

What is the difference between biotic and abiotic components?

Accepted Answer

Biotic components are anything that is living (plants, animals, bacteria, etc.)

Abiotic components are anything that is not living (rocks, soil, air, etc.)

Question 3

What is the biosphere?

Accepted Answer

The sum of all ecosystems on earth

Question 4

What is a biome?

Accepted Answer

A large, natural community of biotic (living) organisms interacting within a major habitat

(tundra, grassland, desert, etc.)

Question 5

What is the difference between an ecosystem and a biome?

Accepted Answer

An ecosystem includes all biotic and abiotic factors in an environment

A biome is a collection of different ecosystems that share a similar climate

Question 6

What is a predator-prey relationship?

Accepted Answer

A relationship where a predator is some organism eats another organism (prey)

(a wolf eating a deer)

Question 7

What is symbiosis?

Accepted Answer

A close and long-term interaction between two species in an ecosystem

(mutualism, commensalism, and paratism)

Question 8

What is biological competition?

Accepted Answer

When two species share limited resources and must compete for those resources

Question 9

What is resource partitioning?

Accepted Answer

Using the available resources in different ways to reduce competition

(giraffes eat higher-up leaves while gazelles eat lower-down leaves)

Question 10

What are keystone species?

Accepted Answer

Species that are fundamental to an ecosystem

Removing keystone species will greatly disrupt an ecosystem

Question 11

What are ecosystem engineers?

Accepted Answer

A type of keystone species that modify their ecosystem in a way that maintains the habitat for other organisms

(elephants leave big paths which help stop wildfires)

Question 12

What are terrestrial biomes?

Accepted Answer

All biomes that exist on land

Question 13

Desert

Accepted Answer

A dry biome that receives very little rainfall and has low primary productivity

Plants in deserts must adapt to having little water

Question 14

Savanna

Accepted Answer

A dry grassland spotted with low-lying shrubs and scattered trees; between a desert and a forest

Has distinct dry/wet seasons, but not too much rainfall

Question 15

Tropical Rainforest

Accepted Answer

A hot, moist biome that receives rainfall all year and is incredibly biodiverse

Found close to the equator; typically low soil quality due to fast nutrient uptake

Question 16

Temperate Grassland

Accepted Answer

An open and flat biome filled with grass; medium rainfall and soil productivity

Question 17

Shrubland

Accepted Answer

A biome made up of shrubs that thrive on steep rocky slopes; not enough rain to support trees and low productivity

Frequent fires due to lightning in the hot summers

Question 18

Temperate Seasonal/Deciduous Forest

Accepted Answer

A biome with hot summers and cold winters (seasons); tall trees and high primary productivity

Leaves change colors, fall off, and grow back to adapt to the temperature

Question 19

Temperate Rainforest

Accepted Answer

A coastal biome with mild summers and winters and heavy rainfall

In temperate (more Northern or Southern) regions as opposed to the Tropical Rainforest

Question 20

Taiga

Accepted Answer

A forest in a cold, subarctic region with temperatures often below freezing

Low nutrient levels because soils don't decompose easily in the low temperature

Question 21

Tundra

Accepted Answer

A treeless, frigid biome in the arctic and on the tops of mountains, with a cold climate and very little rainfall

Nutrient-poor soils and low primary productivity; only a couple of plants can survive

Layer of permafrost covering the ground

Question 22

What are aquatic biomes?

Accepted Answer

Biomes that exist in water or have water as a key component

Question 23

What is salinity?

Accepted Answer

The concentration of dissolved salt in water

(higher salinity = saltier = more dense)

Question 24

What is turbidity?

Accepted Answer

How cloudy water is; influenced by soil runoff

(high turbidity = very cloudy)

Question 25

Wetlands

Accepted Answer

Biomes whose soil is either permanently or periodically saturated with water

Different from lakes, as wetlands are shallow and may dry out

(marshes, swamps, bogs, mudflats, salt marshes)

Question 26

Why are wetlands important?

Accepted Answer

Store excess water from floods

Remove excess nutrients from runoff

Provide a unique, lush habitat that is filled with biodiversity

Question 27

What is emergent vegetation?

Accepted Answer

Wetland plants that have roots underwater in the soil but extend out of the water

(grown in wetlands because wetlands are shallow)

Question 28

Lakes and Ponds

Accepted Answer

BIomes naturally filled with standing freshwater

(ponds = smaller; lakes = bigger)

Question 29

What is the difference between oligotrophic lakes and eutrophic lakes?

Accepted Answer

Oligotrophic lakes have low productivity (low nitrogen and phosphorus)

Eutrophic lakes have high productivity (also higher turbidity from nutrients)

(mesotrophic lakes are in between)

Question 30

Streams and Rivers

Accepted Answer

An aquatic biome with flowing freshwater

Freshwater fish exist here

Question 31

Mangrove Swamps

Accepted Answer

Coastal wetlands in tropical/subtropical regions with trees whose roots are constantly submerged in water

Important for having high biodiversity and preventing erosion by breaking waves

Question 32

The Open Ocean

Accepted Answer

Water in the ocean beyond what is near the shore; contains deep water that the sun cannot penetrate

Question 33

Intertidal Zones

Accepted Answer

Narrow bands along the coast that experience a range of environmental conditions due to the rising/receding tide

(including daily changes in sunlight, temperature, and water; barnacles, sea stars, crustaceans, etc.)

Question 34

Coral Reefs

Accepted Answer

Vast ecosystems built on the exoskeletons of coral polyps; contain many biodiverse plants and animals

Found in warm, shallow, sunlit waters

Question 35

What are polyps?

Accepted Answer

Tiny animals that form massive colonies and build coral reefs by secreting a protective limestone exoskeleton

The exoskeleton remains after polyps die, providing a platform for other organisms in the reef

Question 36

How do polyps and algae interact?

Accepted Answer

Algae provide the polyps with food and oxygen via photosynthesis

Polyps provide the algae with carbon dioxide via cellular respiration

Question 37

Why are coral reefs important?

Accepted Answer

Remove CO2 from the atmosphere to moderate temperatures

Act as natural barriers against erosion

Provide habitats for many species

Question 38

What is coral bleaching?

Accepted Answer

When increased stress causes algae in coral reefs to die off, leaving only a "bleached" skeleton remaining

(increased temperature, acidity, etc.)

Question 39

Estuary

Accepted Answer

An area where a freshwater river/stream meets the ocean

Water is brackish (slightly salty)

Question 40

What are biogeochemical cycles?

Accepted Answer

Pathways for chemical substances to cycle through the biotic and abiotic parts of the earth

(carbon cycle, nitrogen cycle, phosphorus cycle, hydrologic cycle)

Question 41

What are carbon sinks?

Accepted Answer

Anything that absorbs more carbon from the atmosphere than it releases

(plants, the ocean, soil, etc.)

Question 42

What are carbon sources?

Accepted Answer

Anything that releases more carbon than it absorbs

(burning of fossil fuels, volcanic eruptions, etc.)

Question 43

What is the carbon cycle?

Accepted Answer

The movement of carbon between sources and sinks on Earth

Question 44

What are the two stages of the carbon cycle?

Accepted Answer

Fast carbon cycle: the movement of carbon between living organisms and the atmosphere (animals release their carbon when they die)

Slow carbon cycle: the movement of carbon between the lithosphere (rocks), soil, ocean, and atmosphere (takes millions of years)

Question 45

How does photosynthesis affect the carbon cycle?

Accepted Answer

Plants uptake carbon from the atmosphere and store it within their tissues

(eventually the plant will die, and decomposers will release the stored carbon back into the soil)

Question 46

What is the ocean-atmosphere carbon exchange?

Accepted Answer

The process of the ocean absorbing some CO2 from the atmosphere and releasing roughly the same amount

(the ocean is a huge carbon sink)

Question 47

What is sedimentation?

Accepted Answer

The process of CO2 combining with calcium ions in the ocean to form calcium carbonate, which accumulates as sediment

Question 48

What causes annual fluctuations in carbon dioxide concentration?

Accepted Answer

Green plants do more photosynthesis in the summer and less in the winter

(i.e., levels of photosynthetic activity is seasonal)

Question 49

How can humans disrupt the carbon cycle?

Accepted Answer

Using fossil fuels extracts carbon from the ground faster than sedimentation deposits it back in

Deforestation reduces the number of plants to absorb carbon (forests are huge carbon sinks)

Question 50

What is the nitrogen cycle?

Accepted Answer

The cycle of processes that move nitrogen through both biotic and abiotic elements of the earth

Question 51

What is nitrogen fixation?

Accepted Answer

The process that turns nitrogen gas () into nitrate () so that plants can use it

(see how it occurs)

Question 52

What are the two ways nitrogen fixation can occur?

Accepted Answer

Biotically: nitrogen-fixing bacteria convert  into ammonia, which becomes ammonium, and is then converted into nitrate in nitrification

Abiotically:  can directly be turned into nitrate when it is exposed to lightning or industrial processes

Question 53

What is nitrification?

Accepted Answer

The process that converts ammonia and other compounds into nitrite () and then nitrate ()

Question 54

What is nitrogen assimilation?

Accepted Answer

The process that plants use to form organic nitrogen compounds from inorganic nitrogen compounds

(plants cannot use inorganic nitrogen compounds directly, so they rely on assimilation)

Question 55

What is ammonification?

Accepted Answer

The process of decomposers breaking down organic into inorganic ammonium

Question 56

What is denitrification?

Accepted Answer

The process of bacteria reducing nitrite and nitrate to gaseous forms of nitrogen so that it can return back to the atmosphere

->

Question 57

How do humans disrupt the nitrogen cycle?

Accepted Answer

By inserting excess nitrogen into ecosystems, for example, by overuse of nitrogen-based fertilizers

(can lead to algal blooms and other disruptions)

Question 58

What is the phosphorus cycle?

Accepted Answer

The biogeochemical cycle that describes the movement of phosphorus through biotic and abiotic components of earth

Question 59

How does weathering affect the phosphorus cycle?

Accepted Answer

Most phosphorus is found in rocks; weathering these rocks releases phosphorus

Question 60

How is phosphorus absorbed by living organisms in the phosphorus cycle?

Accepted Answer

Plants absorb phosphorus dissolved in soil water and animals eat plants containing phosphorus

Question 61

Why is the phosphorus cycle so slow?

Accepted Answer

Phosphorus is released from rocks, which can take thousands of years to break down due to weathering

There is no gaseous phase

Question 62

How does phosphorus in organisms return to the ecosystem?

Accepted Answer

Decomposers break down dead organisms, converting the phosphorus back to an inorganic form

Question 63

What happens after phosphorus enters the ocean?

Accepted Answer

It is deposited into sediments at the bottom of the ocean and is eventually returned to mountains through geological uplift

Question 64

What is the hydrologic cycle?

(the water cycle)

Accepted Answer

The biogeochemical cycle that describes how water moves through earth

Unit 1 - The Living World: Ecosystems, AP Environmental Science Flashcards