UNIT 7 ck12’s 6.10-6.12

Question 1

What are the main limiting factors for terrestrial organisms?

Answer 1

Temperature and moisture

Terrestrial biomes are defined in terms of these abiotic factors.

Question 2

What are the main limiting factors for aquatic organisms?

Answer 2

Availability of sunlight and concentration of dissolved oxygen and nutrients

These factors vary from place to place in a body of water.

Question 3

What is the maximum depth of the photic zone?

Answer 3

200 meters (656 feet)

This zone allows for photosynthesis and supports biodiversity.

Question 4

What characterizes the aphotic zone?

Answer 4

Water deeper than 200 meters with little to no sunlight

Photosynthesis cannot occur in this zone.

Question 5

How do organisms in the aphotic zone obtain food?

Answer 5

Through chemosynthesis or food drifting down from the water above

Fewer living organisms are found in the aphotic zone compared to the photic.

Question 6

Fill in the blank: The photic zone allows for _______ to occur.

Answer 6

photosynthesis

Question 7

True or False: The aphotic zone has a high level of biodiversity.

Answer 7

False

Fewer living organisms are found in the aphotic zone.

Question 8

What is the photic zone?

Answer 8

Gets enough sunlight for photosynthesis and has more living organisms.

The photic zone is typically found in the upper layers of water bodies where light penetration is sufficient for photosynthetic activity.

Question 9

What is the aphotic zone?

Answer 9

A zone that gets little or no sunlight, resulting in the absence of photosynthetic organisms and fewer living organisms.

The aphotic zone is typically found at depths greater than 200 meters in the ocean.

Question 10

What is the benthic zone?

Answer 10

The benthic zone extends from the shoreline to the bottom of the ocean.

Question 11

What type of organisms are commonly found in the benthic zone?

Answer 11

Many organisms found here are scavengers and decomposers.

Question 12

What is the intertidal zone?

Answer 12

The area along the coastline where ocean water meets land between high and low tides

It is closest to the shore.

Question 13

What is the neritic zone?

Answer 13

The region of shallow water where there is enough sunlight for photosynthesis; has relatively great biomass and biodiversity.

The neritic zone is typically found over the continental shelf.

Question 14

What is the oceanic zone?

Answer 14

Exists in the open ocean beyond the continental shelf

Question 15

What is a characteristic of the oceanic zone?

Answer 15

Has lower concentrations of dissolved nutrients

Question 16

How does the density of organisms in the oceanic zone compare to the neritic zone?

Answer 16

Lower density of organisms than in the neritic zone

Question 17

What is the relationship between dissolved oxygen levels and water depth in lakes and oceans?

Answer 17

Water near the surface usually has more dissolved oxygen than deeper water.

Question 18

Why does water near shore have more dissolved nutrients than water farther from shore?

Answer 18

Most nutrients enter the water from land, carried by runoff, streams, and rivers.

Question 19

What is the benthic zone?

Answer 19

The benthic zone is the bottom of aquatic biomes where dead organisms sink.

Question 20

What role do benthic decomposers play in aquatic biomes?

Answer 20

Benthic decomposers break down dead organisms and release their nutrients into the water.

Question 21

What is the oceanic zone?

Answer 21

The oceanic zone is far from shore, contains fewer dissolved substances, and receives sunlight only near the surface.

Question 22

What adaptations do organisms in marine biomes have for dealing with salt?

Answer 22

Many have organs for excreting excess salt.

Question 23

Which two ocean zones are particularly challenging for marine organisms?

Answer 23

The intertidal zone and the deep ocean.

Question 24

What characterizes the intertidal zone?

Answer 24

It is covered by water at high tide and exposed to air at low tide.

Question 25

What are the conditions in the intertidal zone that require adaptations in organisms?

Answer 25

Constant movement of water and changing temperatures.

Question 26

Fill in the blank: The _______ zone is the narrow strip along the coastline that is covered by water at high tide.

Answer 26

intertidal

Question 27

What are the conditions that organisms living deep in the ocean must withstand?

Answer 27

Extreme water pressure, very cold water, complete darkness ## Footnote These conditions create a unique environment for deep-sea organisms.

Question 28

Where do organisms thrive in the deep ocean?

Answer 28

Around hydrothermal vents ## Footnote Hydrothermal vents provide a unique ecosystem despite extreme conditions.

Question 29

What do hydrothermal vents release?

Answer 29

Hot water containing chemicals ## Footnote These chemicals are toxic to most living things but support specialized life forms.

Question 30

What type of producers are found near hydrothermal vents?

Answer 30

Single-celled chemoautotrophs ## Footnote Chemoautotrophs use energy from chemicals to produce food.

Question 31

What is the purpose of Marine Protected Areas?

Answer 31

To allow fish to breed, grow large, and replenish state waters ## Footnote These areas are established as no-fishing zones.

Question 32

What are Marine Protected Areas?

Answer 32

No-fishing zones ## Footnote These zones are intended to protect marine ecosystems.

Question 33

What is an important issue related to fish populations?

Answer 33

Overfishing ## Footnote Overfishing can lead to dwindling fish populations and ecosystem imbalance.

Question 34

What do scientists do in Marine Protected Areas?

Answer 34

Monitor the areas to determine if fish populations are replenishing ## Footnote Monitoring helps assess the effectiveness of these protected zones.

Question 35

Fill in the blank: Organisms that cluster around hydrothermal vents are known as _______.

Answer 35

chemoautotrophs ## Footnote Chemoautotrophs are key to the food web in extreme environments.

Question 36

What are freshwater biomes primarily characterized by?

Answer 36

Water that contains little or no salt.

Question 37

What types of freshwater biomes are there?

Answer 37

Standing and running freshwater biomes.

Question 38

What are examples of standing freshwater biomes?

Answer 38

Ponds and lakes.

Question 39

What is the aphotic zone in lakes?

Answer 39

A zone where there is too little sunlight for photosynthesis.

Question 40

Fill in the blank: Lakes contain water in the _______ zone where photosynthesis is not possible.

Answer 40

aphotic

Question 41

What are the two main types of running freshwater biomes?

Answer 41

Streams and rivers ## Footnote Rivers are usually larger than streams.

Question 42

How do streams typically begin?

Answer 42

With runoff or water seeping out of a spring

Question 43

What happens to streams as they flow downhill?

Answer 43

They join other running water to become a stream

Question 44

What type of water do rivers typically empty into?

Answer 44

A lake or the ocean

Question 45

How does running water compare to standing water in terms of oxygen and nutrient dissolution?

Answer 45

Running water is better able to dissolve oxygen and nutrients

Question 46

Who are the primary producers in running water biomes?

Answer 46

Algae and plants, such as cattails

Question 47

What defines a wetland?

Answer 47

An area that is saturated with water or covered by water for at least one season of the year

Question 48

What types of water can wetlands contain?

Answer 48

Freshwater or saltwater

Question 49

List four important functions of wetlands.

Answer 49

* Store excess water from floods * Slow down runoff and help prevent erosion * Remove excess nutrients from runoff * Provide unique habitats for certain plant communities

Question 50

Why are wetlands considered to have high biodiversity?

Answer 50

They provide a safe, lush habitat for many species of animals

Question 51

What are the three broad groups of aquatic organisms?

Answer 51

Plankton, nekton, and benthos ## Footnote These groups are categorized based on their movement and habitat.

Question 52

What defines plankton?

Answer 52

Tiny aquatic organisms that cannot move on their own ## Footnote Plankton live in the photic zone.

Question 53

What are the two types of plankton?

Answer 53

* Phytoplankton * Zooplankton ## Footnote Phytoplankton are bacteria and algae; zooplankton are tiny animals that feed on phytoplankton.

Question 54

What do phytoplankton use to make food?

Answer 54

Sunlight ## Footnote Phytoplankton are a key part of the aquatic food web.

Question 55

What do zooplankton feed on?

Answer 55

Phytoplankton ## Footnote Zooplankton play a crucial role in the transfer of energy in aquatic ecosystems.

Question 56

What characterizes nekton?

Answer 56

Aquatic animals that can move on their own by swimming ## Footnote Nekton may inhabit either the photic or aphotic zone.

Question 57

What do nekton typically feed on?

Answer 57

* Plankton * Other nekton ## Footnote Nekton includes various species such as fish and shrimp.

Question 58

What are benthos?

Answer 58

Aquatic organisms that crawl in sediments at the bottom of a body of water ## Footnote Many benthos are decomposers.

Question 59

Give examples of benthos.

Answer 59

* Sponges * Clams * Anglerfish ## Footnote Anglerfish are adapted to life in dark environments.

Question 60

Fill in the blank: Plankton live in the _______ zone.

Answer 60

photic ## Footnote The photic zone is where sunlight penetrates the water.

Question 61

Fill in the blank: Nekton include animals like _______ and shrimp.

Answer 61

fish ## Footnote Fish are a common example of nekton.