Modern biological classification systems differ from outdated systems because they consider

a.
biological biodiversity.

b.
environmental changes.

c.
evolutionary relationships.

d.
morphological comparisons.

What are two ways in which waves erode the land?

Select the correct answer from each drop-down menu. during the day, plants produce by splitting water molecules in the light-dependent reactions of photosynthesis. at the same time, plants use cellular respiration to produce some of the needed by the light-independent reactions to make sugars. during the night, plants produce because takes place.

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled