Many of the Signaling Pathways Used for Signaling Between Cells

question 133

Multiple Choice

Many of the signaling pathways used for signaling between cells in complex multicellular organisms first evolved in:

• A)unicellular eukaryotes.
• B)simple multicellular eukaryotes.
• C)unicellular prokaryotes.
• D)simple multicellular prokaryotes.
• E)complex multicellular prokaryotes.

---

Definitions:

π Molecular Orbital

A molecular orbital formed by the side-to-side overlap of atomic orbitals, commonly p orbitals, leading to the formation of a bonded region of electron density above and below the plane of the atomic nuclei.

Allyl Radical

A molecular entity consisting of an alkene with a CH2-CH=CH2 structure where a hydrogen atom is removed, leaving an unpaired electron.

Major Organic Product

The primary product of a chemical reaction that has the highest yield, relative to other potential products.

Cycloheptene

A cyclic hydrocarbon with the molecular formula C7H12, featuring a seven-membered ring with one double bond.