Thirteen-Year-Old Juan Has Had His First Ejaculation.This Is

question 104

Multiple Choice

Thirteen-year-old Juan has had his first ejaculation.This is

• A) a sign of complete sexual maturation.
• B) called spermarche.
• C) this is a clear-cut marker of the onset of sexual maturity.
• D) called menarche.

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Definitions:

Facilitated Diffusion

A process of passive transport, facilitated by transport proteins, allowing molecules to move across cell membranes along a concentration gradient without energy expenditure.

Active Transport

The movement of substances across cell membranes against their concentration gradient, requiring energy.

Cotransport Systems

Mechanisms in cell membranes that transport two different molecules across the membrane in the same direction.

Active Transport

The movement of molecules across a cell membrane from a region of lower concentration to one of higher concentration, requiring energy.