Down syndrome in humans is due to
A. two Y chromosomes.
B. trisomy (three copies of chromosome 21).
C. three X chromosomes.
D. monosomy (one copy of chromosome 21).
Answer: B
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A major chemical used to preserve meat products is ________.
A. refrigeration B. nitrite C. propionate D. ethylene oxide
Which reefs are directly impacted by human activity the most?
a. Barrier reefs b. Fringing reefs c. Patch reefs d. Atolls
Answer the following statements true (T) or false (F)
1. In eukaryotic cells the electron transport system occurs in the mitochondria. 2. In prokaryotic cells the electron transport system occurs in the mitochondria. 3. Chemiosmotic phosphorylation occurs when protons pass through ATP synthase and combine with oxygen and electrons to make water. 4. Substrate-level phosphorylation occurs when protons pass through ATP synthase and combine with oxygen and electrons to make water. 5. Anaerobic respiration uses oxygen as its final electron acceptor at the end of the electron transport chain.
This animal is radially symmetric, has
nematocysts, and cnidocytes. This animal is ___.
a. a jellyfish b. an earthworm c. a sea anemone d. a sponge e. more than one of these