Question

lesson 2 - what could be causing the trout population to change?
where have all the creatures gone?

1. what is one reason the timberline is moving higher up mountains?

a) more trees are being planted
b) the climate is getting colder
c) the climate is getting warmer
d) animals are eating all the trees

1. how did humboldt penguins most likely arrive in alaska?

a) they flew across the ocean
b) they swam the whole way
c) they were moved by humans on ships
d) they walked over land

1. what is one challenge the california red - legged frog faces?

a) there are too many trees
b) their habitats are being destroyed by farming and building
c) the climate is getting colder
d) they have too much food

1. what do biologists do to understand why populations change?

a) guess the answers
b) collect data and ask questions about interactions
c) ignore the changes
d) move animals to new places

Explanation:

1. Timberlines shift upward as warmer temperatures allow trees to grow at higher elevations that were previously too cold.
2. Humboldt penguins are native to South America; they cannot fly long distances, swim such a vast ocean, or cross land to Alaska, so human transport via ships is the most plausible cause.
3. The California red-legged frog's primary threat is habitat loss from human activities like agriculture and development.
4. Biologists use empirical methods, including data collection and analyzing species interactions, to study population changes, rather than guessing, ignoring changes, or relocating animals as a research method.

Answer:

1. c) The climate is getting warmer
2. c) They were moved by humans on ships
3. b) Their habitats are being destroyed by farming and building
4. b) Collect data and ask questions about interactions