What is a well-known issue with cross-sectional methodology?

This methodology enables to measure simultaneously both the result and exposure in the group under study

Explanation:

A cross-sectional method is a type of scientific design based on observational data. The cross-sectional studies involve the use of diverse groups that differ in the variable investigated but share other features (for example, individuals with the same educational background, ethnicity, economic status, etc). This class of studies is generally used in developmental psychology.

before it leaves the nucleus of a eukaryotic cell, mrna is altered in the following ways: - a cap is added to the 5' end of the mrna molecule; - a poly a tail is added to the 3' end; - introns are removed and exons are spliced together.

in a chemical reaction, the atoms and molecules produced by the reaction are called products. no new atoms are created, and no atoms are destroyed. in a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.