Lichens are not single organisms, but algae and fungi that function together. The algae use photosynthesis to make food for both organisms. The fungi produce digestive chemicals and absorb nutrients for both organisms. How does the biological activity of lichens cause weathering in rocks?
Answer options with 4 options
A.
Lichens cause friction as they grow, which weathers the rocks.
B.
Lichens produce chemicals, which dissolve and weather the rocks.
C.
Lichens take in water, which freezes in cracks and weathers the rocks.
D.
Lichens absorb heat during photosynthesis, which weathers the rocks.

B

Explanation:

Lichens also have significant impact in the chemical weathering of rocks by the excretion of various organic acids, particularly oxalic acid, which can effectively dissolve minerals and chelate metallic cations.

.) the observation by semmelweis that more mothers died of childbed fever when their doctors also worked in the morgue

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.