Melatonin is secreted by the pineal gland to control circadian rhythms

Trends in the cell theory (3)

1. All cells are small 2. All living things are made up of cells 3. Cells come from preexisting cells

Discrepancies in the cell theory (3 +1)

1. Giant algae: giant unicellular organism 2. Mammal skeletal muscle: organism with more than one nucleus 3. Aseptate fungal hyphae: not made of clearly defined cells 4. red blood cells: eukaryotic cell without a nucleus (when maturing, the mitochondria and nucleus are discarded)

Discrepancy

anomaly found in the set of data or characteristics

Trend

general pattern found in data or characteristics

Circadian rhythm

the body's biological clock, adapting humans to live on a 24 hour schedule

Outline the mechanism that regulates melatonin secretion in response to the day-night cycle

Suprachiasmatic nucleus (SCN): 1. Eyes detects blue light (460-480 nm) 2. Sends signals to SCN 3. Melatonin levels are increased in response to the signal from light Light detection Signal to SCN Melatonin adjusted