5. Membrane receptors are specialized proteins that take part in communication between the cell and the outside world. The membrane protein receptor can be subdivided into three parts or domains. The portion of the protein in the E zone is extracellular (outside of the cell). The P zone is the plasma membrane and the l zone is intracellular (inside of the cell).

"do a testcross with a homozygous recessive plant."

i know can you plzz me with this question im sorry i didt answer your question i just need hel.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds