Eumelanin and pheomelanin are
A) brownish-black and reddish-yellow pigments, respectively.
B) reddish-yellow and brownish-black pigments, respectively.
C) present in excess in a person with albinism.
D) types of keratin.
A
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The placenta and its attached fetal membranes are collectively called the afterbirth
Indicate whether the statement is true or false
The following local chemical changes occur during a period of increased cell activity except
a. increased CO2. b. increased acid. c. increased O2. d. increased K+. e. increased osmolarity.
These muscles extend from the pubis and ischium anteriorly to the sacrum and coccyx posteriorly. They control the evacuation of waste materials from the digestive and urinary systems.
A. Muscles of the pharynx B. Muscles of the abdominal wall C. Muscles of the pelvic floor D. Muscles of the vertebral column E. Muscles of the perineal floor
The chemoreceptor reflexes help maintain homeostasis
A. under normal conditions. B. when carbon dioxide levels increase. C. when stimulated by changes in blood osmotic pressure. D. when epinephrine levels increase. E. when hydrogen ion concentrations decrease.