a. The circulatory system is made up of the heart plus all of the and .

Hector is back from his morning run and is feeling lightheaded because his energy is depleted. which food item will provide him with a quick source of carbohydrates? a. fruit juice b. tuna fish c. scrambled eggs and butter d. beans

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome

The graph shows the amount of global warming happening in different ecosystems. which populations of organisms will likely decline the most as a result of climate change, and why? a.coral reefs because of the loss of the symbiotic algae living within their bodies b.penguin populations because the fish they eat will move into warmer waters c.mountain-dwelling birds because rising sea levels will relocate their food sources d.large cats in the rainforest because of decreased habitat loss for their prey