By 3.2 billion years ago, chemosynthetic cells had
become established
a. near deep-sea hydrothermal vents.
b. in salt lakes.
c. in hot, highly acidic, fresh-water springs.
d. in deep oceanic sediments.
e. in the upper sunlit waters of the open oceans.
Answer: a
You might also like to view...
Use the following study to answer the following question(s): A researcher applies varying amounts of fertilizer (0, 2, 4, 8, 10 units) to 50 potted tomato plants. All other variables that may affect the outcome (watering, temperature, sunlight, plant size, etc.) are kept the same from pot to pot. At the end of the growing season, the tomatoes grown on each plant are weighed to determine which fertilizer level produced the largest tomato yield.Which variable is the dependent variable?
A. The plant size at the end of the growing season B. The tomato yield at the end of the growing season C. The temperature D. The fertilizer amount
Cells with a double set of genetic information are described by the term
a. polyploid. b. diploid. c. triploid. d. haploid. e. tetraploid.
Which of the following feeding strategies is incorrectly paired with its feeding adaptations?
a. carnivores?well-developed canine teeth b. herbivores?stomachs containing symbiotic bacteria and protists c. animals that feed on body fluids?piercing and sucking mouth parts d. nectar feeders-long tongue e. suspension feeders?poison glands
Chloramphenicol is an antibiotic that targets prokaryotic (70S) ribosomes, but not eukaryotic (80S) ribosomes. Which of these questions stems from this observation, plus an understanding of eukaryotic origins?
A) Can chloramphenicol also be used to control human diseases that are caused by archaeans? B) Can chloramphenicol pass through the capsules possessed by many cyanobacteria? C) If chloramphenicol inhibits prokaryotic ribosomes, should it not also inhibit mitochondrial ribosomes? D) Why aren't prokaryotic ribosomes identical to eukaryotic ribosomes?