Once a Planetesimal Is Large Enough, It Grows by

question 47

Multiple Choice

Once a planetesimal is large enough, it grows by

• A) electric charges attracting other charged material.
• B) generating new mass within itself.
• C) passing close to its star or protostar.
• D) attracting more material through gravitation.
• E) heating up and sticking to encountered material.

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Definitions:

Plant Hormone

Naturally occurring organic compounds in plants that regulate growth, development, and responses to stimuli.

Rhodopsin

Visual purple; a light-sensitive pigment found in the rod cells of the vertebrate eye; a similar molecule is employed by certain bacteria in the capture of light energy to make ATP.

Signal Transduction

Signal transduction is the process by which a cell responds to external signals, converting them into cellular responses through a complex series of events.

Enzyme-Linked Receptor

A type of cell surface receptor that, upon binding to its ligand, activates an intrinsic enzymatic activity, leading to a cellular response.