Answer:
Oxygen in the atmosphere is a molecule because it contains molecular bonds. It is an element because it is made from atoms of only one element - oxygen.
Explanation:
Answer:
C. A hillside that has been cleared by a volcanic eruption.
Explanation:
Pioneer species are hardy species which are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by fire or other natural disasters. Some lichens grow on rocks without soil, so may be among the first of life forms, and break down the rocks into soil for plants.
Hope this helps!
<span>inanimate non-living alive dead</span>
Answer: creating an ozone layer to shield life from UV rays
Cynobacteria or blue green algae is the strain of bacteria, which was able to produce oxygen in the primitive earth as a result of photosynthesis. The abundance of oxygen in the atmosphere formed the ozone layer in the upper atmospheric layers, these layers are protective enough to provide a shield against the harmful UV radiations incident on earth coming from the sun.
