HELP ME OUT PLEASE KISSES WILL BE AWARDED

During convection, less dense fluid rises and denser fluid sinks.

What kinds of molecules can pass through the cell membrane without any problem?

What is the purpose of transcription? a. to copy the nucleotide in dna b. to form rna molecules from dna c. to produce a nucleic acid sequence from an amino acid sequence d. to link amino acids together to form stands of protein