Question

Biodiversity Unit Test
2 of 132 of 13 Items




Question
Based on the data below, which group of animals are genetically diverse?
# of different type of species in the world
Birds 9,000+
Bears 8
Horses 350+
Whales 90


(1 point)
Responses

whales

horses

birds

bears

Answer 1

birds

Answer 2

Which biome best supports animals that feed mostly by grazing on grasses and small shrubs?(1 point)
Responses

tropics
tropics

mixed forests
mixed forests

polar desert
polar desert

savanna

Answer 3

savanna

Answer 4

Which describes a primary role of the pioneer species in an ecosystem?(1 point)
Responses

protect other species from danger
protect other species from danger

prevent fertile soil from washing away
prevent fertile soil from washing away

provide food for small animals
provide food for small animals

break down rock into soil

Answer 5

break down rock into soil

Answer 6

What happens after coral is bleached?(1 point)
Responses

The coral is susceptible to starvation.
The coral is susceptible to starvation.

The coral produces peroxides.
The coral produces peroxides.

The coral dies immediately.
The coral dies immediately.

The coral releases algae into the ocean.

Answer 7

The coral is susceptible to starvation.

Answer 8

The most biodiverse ecosystem in the world is likely a(1 point)
Responses

taiga.
taiga.

coral reef.
coral reef.

cold desert.
cold desert.

tundra.

Answer 9

coral reef.

Answer 10

Biodiversity Unit Test
7 of 137 of 13 Items





Question
Marine biologist Dr. James Estes researched sea otters and their habitats in the Aleutian Islands of the North Pacific Ocean. Sea otters feed on animals such as crabs and urchins. Islands with sea otters contained a lot of kelp, a seaweed that is an important food source for fish and other sea animals. However, Islands without otters had large populations of urchins but no kelp since sea urchins feed on this seaweed. Since sea otters are able to control the population of urchins, this allows for kelp to freely grow in those areas. Given this information, what term best describes the otter in the Aleutian Islands ecosystem?(1 point)
Responses

decomposer
decomposer

apex predator
apex predator

producer
producer

keystone species

Answer 11

keystone species

Answer 12

Dolphins are animals that live in water, but they do not have gills. What might this suggest about dolphins?(1 point)
Responses

They have another structure to obtain oxygen.
They have another structure to obtain oxygen.

They do not need oxygen.
They do not need oxygen.

They do not need to release carbon dioxide.
They do not need to release carbon dioxide.

They make their own food.

Answer 13

They have another structure to obtain oxygen.

Answer 14

Which of the following is one response to higher temperatures in a habitat?(1 point)
Responses

more sweating
more sweating

more movement
more movement

thicker fur
thicker fur

more fat storage

Answer 15

thicker fur

Answer 16

Why is fever an effective response to pathogens?(1 point)
Responses

It can remove pathogens from the body.
It can remove pathogens from the body.

It can signal the body to run.
It can signal the body to run.

It can inactivate pathogens in the body.
It can inactivate pathogens in the body.

It can signal the body to fight.

Answer 17

It can signal the body to fight.

Answer 18

Beavers, large members of the rodent family in North America, are often referred to as “ecosystem/keystone engineers” by wildlife managers. Ecosystem engineers are described as animals that create, alter, or destroy a habitat. Beavers contribute to river ecosystems by bringing down old and dead trees along riverbanks. They use these trees to make their dams. Although these dams are primarily used for protection and food storage, scientists report that these dams change the surrounding environment in different ways.


Given this information, in three to five sentences, describe a potential benefit that beavers contribute to the ecosystem as keystone engineers and describe a plausible impact that the removal of beavers could have on the surrounding ecosystem.

Answer 19

The benefits beavers contribute to the ecosystem as keystone engineers include creating small ponds, which can increase the number of aquatic plants and insects. Additionally, the dams that beavers construct can help reduce flooding downstream by slowing the water flow. The removal of beavers from the ecosystem can lead to a loss of these benefits, dead trees that beavers use will no longer be brought down and stored, leading to an increase of debris lining riverbanks. Without the presence of beavers, water flow will change, which cause eroded banks, and aquatic plant and animal species loss.

Answer 20

in 3 sentences

Answer 21

Sure, here's a shortened version:

Beavers as keystone engineers benefit the ecosystem by creating small ponds, increasing the number of aquatic plants and insects, and decreasing flooding downstream. The removal of beavers could lead to debris buildup, habitat loss, and erosion in riverbanks, among other negative impacts. Therefore, wildlife managers consider beavers an essential species for maintaining the health and biodiversity of river ecosystems.

Answer 22

A bird-watcher sees a small yellow bird in a tree. Explain to the bird-watcher how he can use a dichotomous key to identify the bird. Assume he does not know anything about dichotomous keys. Then, write two steps of a dichotomous key that would be helpful for the bird-watcher.

Answer 23

A dichotomous key is a tool that helps identify unknown organisms based on observable traits. To identify the small yellow bird in the tree, the bird-watcher will have to compare the characteristics of the bird with those listed in the dichotomous key.

First, the bird-watcher needs to locate a dichotomous key that includes birds in the area where they are observing. Then, they can follow a series of steps in the dichotomous key to narrow down the possibilities until they reach the bird's species.

Two steps of the dichotomous key could be:

1. Does the bird have a black mask over its eyes?
- Yes: go to step 2
- No: go to step 3

2. Does the bird have a white belly?
- Yes: the bird is a Yellow Warbler
- No: the bird is a Common Yellowthroat

3. Does the bird have black stripes on its wings?
- Yes: the bird is a Pine Warbler
- No: go to step 4

And so on until the bird is identified.

Answer 24

js 2 steps

Answer 25

Sure, here are two sample steps of a dichotomous key to identify the small yellow bird:

1. Does the bird have a black bill?
- Yes: go to step 2
- No: go to step 3

2. Is the bird's body larger than a sparrow?
- Yes: the bird might be a Western Tanager
- No: the bird might be a Wilson's Warbler

And so on until the bird is identified.

Answer 26

Rainbow trout live in the rivers and streams of upstate New York. Rivers in this area are cold and have strong currents. If temperatures fall over time because of climate change, what is one variation that would likely help the trout to survive? Why? Write 1-2 sentences.

Answer 27

One variation that could help the rainbow trout to survive a temperature fall caused by climate change is developing a tolerance for colder water. This would enable the trout to adapt to the changing temperature by continuing to thrive in colder environments.