Which of the following organisms has a gastrovascular cavity?
A) hydra
B) earthworm
C) clam
D) bird
Answer: A
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You are working in the field with your favorite bacteria species, Bacterium BB. You carry out some experiments with Bacterium BB, and find that it can now degrade toluene and it is pathogenic! What happened?
A. Bacterium BB acquired degradative and virulence plasmids by horizontal gene transfer. B. Bacterium BB picked up fertility and Col-plasmids via conjugation. C. Bacterium BB was exposed to a bacteriophage which is now in its lytic phase. D. Bacterium BB was transformed with a resistance plasmid and a digestive plasmid. E. Bacterium BB sexually reproduced with another strain of bacteria that had both toluene-degrading gene and virulence gene.
New world monkeys have all of the following features except
A. they have flat spreading noses. B. they grasp objects with long prehensile tails. C. they evolved in isolation in South America. D. they are all arboreal. E. they have ischial callosities (thickened rump pads).
Sewage treatment is a way to prevent raw sewage causing
a. oil spills. b. oligotrophy. c. eutrophication. d. global warming. e. coastal erosion.
The cell membranes of archaeons that lack a cell wall are strengthened by ________.
A. diglycerol tetraethers B. diglycerol ethers C. glycoprotein or protein layers D. pseudomurein