Question 1: Which stage of sleep is characterized by the

presence of theta waves and the appearance of sleep

spindles and K-complexes on an EEG?

a) Stage 1

b) Stage 2

c) Stage 3

d) REM sleep

Answer: b) Stage 2

Rationale: Stage 2 sleep is characterized by the presence of

theta waves and the appearance of sleep spindles and Kcomplexes on an EEG. This stage represents approximately

45-55% of total sleep time and is essential for the

consolidation of memory and learning.

Question 2: Which stage of sleep is often referred to as

slow-wave sleep (SWS) and is characterized by the

presence of high-amplitude, low-frequency delta waves on

an EEG?

a) Stage 1

b) Stage 2

c) Stage 3

d) REM sleep

Answer: c) Stage 3