Biological soil crusts<span> are communities of living organisms on the </span>soil<span> surface in arid and semi-arid ecosystems. They are found throughout the world with varying species composition and cover depending on topography, </span>soil<span> characteristics, climate, plant community, microhabitats, and disturbance regimes.</span>
Alveoli walls are composed of Type 1 and Type 2 alveolar cells
Answer:
i think the answer is b
Explanation:
B. Allele frequencies change randomly each generation
