Why do folded mountain belts sometimes form at convergent plate boundaries?
Rock is compressed and forced upward.
® Convergent plate boundaries occur above hot spots.
The rock is stretched apart and breaks, which allows magma
to rise to Earth's surface.
Subducted oceanic lithosphere melts and rises as magma to
Earth's surface.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".

lesson summarykaryotypes a genome is the full set of all the genetic information that an organism carries in its dna. chromosomes arebundles of dna and protein found in the nucleus of a eukaryotic cell.