Which of the following describes RNA -RNA is usually single-stranded and contains uracil
-RNA is made and carries out its functions in the nucleus
-RNA is usually double stranded in contains thymine
-RNA is longer and contains five bases

RNA is usually single stranded and contains uracil

Explanation:

DNA is the one which is double stranded (has a helical structure) and it has the nucleotide bases; Adenine, Thymine, Cytosine and Guanine whilst RNA is single stranded and does not form a double helix like DNA. RNA also has the same nucleotide bases but instead of having Thymine it has Uracil.

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.