Which of the following statements is most correct regarding intracellular chemical signals known as "second messengers"?
Cyclic AMP and calcium may be second messengers.
Which of the following is a principle of the fluid mosaic model of cell membrane structure?
Phospholipids form a bilayer that is largely impermeable to water-soluble molecules.
Cell junction that promote the coordinated activity of cells my physically binding them together into a cell community include all of the following except _________.
Which statement is the most correct regarding transcription/translation?
The nucleotide sequence in a tRNA anticodon is an exact copy of the DNA triplet that coded for it except that Uracil is substituted for thymine.
If the nucleotide or base sequence of the DNA strand used as a template for messenger RNA synthesis is ACTGT, then the sequence of bases in the corresponding mRNA would be:
A gene can best be defined as _____________.
A segment of DNA that carries the instructions for one polypeptide chain.
Which of the following is a function of the plasma membrane protein?
Molecular transport through the membrane.
Which of these is not a function of the plasma membrane?
It prevents potassium ions from leaking out and sodium ions from crossing into the cell.
The endomembrane system is ____________.
An interactive system of organelles whose membranes physicially or functionally connected.