Question

unit 4 test: biomes, succession & biodivers
multiple choice: select the best answer for each question below. do not write on test. use your zipgrade.
matching: match the biome to its characteristics.

1. sea otters feed on sea urchins and help maintain their marine ecosystems by preventing sea urchins from overfeeding on kelp. sea otters are an example of a(n)

a. keystone species
b. indicator species
c. pioneer species
d. secondary species

1. because frogs absorb both oxygen and toxins through their skin, they are very sensitive to air and water quality. this makes them an excellent

a. keystone species
b. indicator species
c. pioneer species
d. primary species

1. which of the following is not true about mangrove trees?

a. their leaves excrete excess salt from brackish (mixture of salt and fresh) water
b. their large roots cause erosion
c. their roots provide shelter for fish and shark species
d. mangroves trees are threatened by tourism and shrimp farming
ing: match the biome to its characteristics.
chaparral a. mountainous, cold, small vegetation & highly insulated animals
deciduous forest b. dry with temperature extremes, little vegetation & nocturnal animals
desert c. hot & dry with mild winters, fire & drought are common
alpine d. grasses are dominant vegetation, little rainfall & tropical climate
savanna e. cold climate with many conifers, animals often hibernate
taiga ab. four distinct seasons, many trees and animals with camouflage

Explanation:

1. Keystone species play a crucial role in maintaining the structure of an ecosystem. Sea otters' role in controlling sea urchin populations to protect kelp (a foundation species) makes them a keystone species.
2. Indicator species are sensitive to environmental changes. Frogs' sensitivity to air and water quality (due to toxin absorption through skin) makes them indicator species.
3. Mangrove roots help prevent erosion (not cause it). They excrete salt, provide shelter, and are threatened by human activities like tourism and shrimp farming.

Answer:

1. A. keystone species
2. B. indicator species
3. B. their large roots cause erosion