Which of the following was probably not present in large amounts in the atmosphere at the time life is thought to have originated? (ebook Major Episodes in the History of Life)
H2O, CH4, H2, and NH3
In their experiment on the origin of organic compounds, which of the following gases did Urey and Miller use to simulate Earth's early atmosphere?
The Urey and Miller experiments (and subsequent, similar experiments) showed that
simple organic molecules can form spontaneously under conditions like those thought to prevail early in Earth's history
Clay particles may have played an important role in the origin of life because
clay particles are a suitable surface for the formation of polymers from monomers
In an experiment, a microbiologist put equal numbers of each of the following organisms into a flask of sterile broth consisting mostly of sugar and a few amino acids. She then placed the flask in the dark. Which of the organisms would be best able to survive?
Prokaryotes that use light for their energy source and CO2 for their carbon source are called
The bacteria that cause tetanus can be killed only by prolonged heating at temperatures considerably above boiling. This suggests that tetanus bacteria
You have been asked to participate in the cleanup of an old mining site. You dislike the idea of handling poisonous acidic soils, so you volunteer to culture the bacterium Thiobacillus. The aspect of the cleanup that you are participating in is
mitochondria and chloroplasts
Which of the following organelles were likely generated through endosymbiosis?
In general, how do algae and protozoans differ?
Algae are photosynthetic, and almost all protozoans are heterotrophic.
Which of these groups includes parasitic unicellular organisms with a complex of organelles specialized for penetrating host cells and tissues?
watch how it moves
A student is looking at a protozoan under the microscope. "I know it's supposed to be a ciliate, a flagellate, or an amoeba, but how am I supposed to know which it is?" she complains to her lab partner. "Easy," her partner says. "Just
Consider the following kinds of organisms: dinoflagellates and ciliates. Both of these organisms belong to which one of the following groups?
This mass of cytoplasm is undivided by membranes and contains many nuclei; therefore, it is not technically multicellular
In lab class a plasmodial slime mold is used as a demonstration organism. One of the students does not understand why the plasmodium is not considered multicellular. How would you explain it to her?