Cyathea spinulosa are considered more advanced than Polytrichum strictum but less advanced than higher plants. Explain why.

Can you identify which of the following groups of organisms are, or are not, populations? a. the american bison (bison bison) and grey wolves (canis lupus) currently living in yellowstone national parkb. all of the rainbow trout (oncorhynchus mykiss that) that have ever lived in lake eriec. the group of american bison (bison bison) currently living in yellowstone national parkd. a group of calliope hummingbirds (selasphorus calliope) and a group of rufous hummingbirds (selasphorus rufus) living in the same new hampshire woodse. the northern cardinals (cardinalis cardinalis) living on opposite shores of lake champlain f. all of the whales currently living in the atlantic ocean off cape cod, massachusetts

Which symbols below represent the ions found in the glass of water ? a. oh- and h+ b. co2 and o2 c. o2 and h2 d. nh3- and h+

Why do we perceive objects as retaining their brightness under different lighting levels?