Our Sleeping-Waking Cycle Follows A(n)__________ Rhythm

question 12

Multiple Choice

Our sleeping-waking cycle follows a(n) __________ rhythm.

• A)infradian
• B)circadian
• C)diurnal
• D)ultradian

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Definitions:

Germ Layer

In early embryonic development, one of the three primary layers (ectoderm, mesoderm, and endoderm) that give rise to all tissues and organs of an organism.

Dermis

The layer of skin beneath the epidermis that contains nerve endings, sweat glands, and hair follicles.

Ectoderm

The outermost of the three primary layers of an embryo that develops into the nervous system, skin, and related structures.

Germ Layer

One of the primary layers of cells (endoderm, mesoderm, ectoderm) in the early embryo that gives rise to all tissues and organs of the organism.