Which of the following best defines muscles?
a. long flexible tendons that connect bones
b. tough strong tissues that provide energy to perform physical activities
c. thick fibrous cartilage that act when sent electrical signals
d. smooth long fibers that are controlled by the skeletal system

In natural selection, what is actually “selected? ” a) alleles are directly selected b) genotypes are directly selected c) phenotypes are directly selected d) entire populations are directly selected

Melting glaciers is a serious threat to the environment what is the possible consequence of melting glaciers on polar bears?

For the strategies below, decide whether they are best described as demand-side solutions or supply-side solutions to meeting human needs for fresh water. remember that a demand-side solution reduces demand for fresh water, whereas a supply-side solution increases the supply of fresh water. (a) damming a river to create a reservoir (b) desalinating seawater (c) a nation invading a neighboring country to access their rivers (d) raising water prices for consumers and businesses (e) providing tax breaks for companies that use less water (f) replacing inefficient irrigation with more-efficient drip irrigation to grow crops (g) requiring low-flow showerheads in all new homes