<span>The mountains were once seas. The land was forced up by tectonic motion when the mountains were formed. The Sahara also used to be a sea and has a valley full of the fossilized remains of an extinct species of whale. It is generally agreed upon that two plates colliding caused the uplift that created the mountainous zone. Same for the Himalayas.</span>
3:they are usually microscopic
The correct answer is uracil.
<span>Uracil is one of the pyrimidine nucleotide bases which is the component of nucleic acid-RNA. In RNA, uracil binds to adenine via two hydrogen bonds (complementary binding). Uracil is not found in DNA, it is replaced by thymine because it is thymine’s demethylated form.</span>
Some Bio life has its own ways of surviving like animals will have more fur if they are in a cold area or Plants being able to survive in the cold