Exam 25: The Origin and Diversification of Eukaryotes

If true, which of the following is the best evidence that the cyanelles are providing nutrition (in other words, calories) to the surrounding cercozoan?

Living diatoms contain brownish plastids. If global warming causes blooms of diatoms in the surface waters of Earth's oceans, how might this be harmful to the animals that build coral reefs?

The next few questions refer to the following description and Table 25.1. Diatoms are encased in Petri-platelike cases (valves) made of translucent hydrated silica whose thickness can be varied. The material used to store excess calories can also be varied. At certain times, diatoms store excess calories in the form of the liquid polysaccharide, laminarin, and at other times as oil. Table 25.1 shows data concerning the density (specific gravity) of various components of diatoms, and of their environment. Table 25.1 Specific Gravities of Materials Relevant to Diatoms -Water's density and, consequently, its buoyancy decrease at warmer temperatures. Based on this consideration and using data from Table 25.1, at which time of year should one expect diatoms to be storing excess calories mostly as oil?

You are given five test tubes, each containing an unknown protist, and your task is to read the following description and match these five protists to the correct test tube. In test tube 1, you observe an organism feeding. Your sketch of the organism looks very similar to Figure 25.1. When light, especially red and blue light, is shone on the tubes, oxygen bubbles accumulate on the inside of test tubes 2 and 3. Chemical analysis of test tube 3 indicates the presence of substantial amounts of silica. Chemical analysis of test tube 2 indicates the presence of a chemical that is toxic to fish and humans. Microscopic analysis of organisms in test tubes 2, 4, and 5 reveals the presence of permanent, membrane-bounded sacs just under the plasma membrane. Microscopic analysis of organisms in test tube 4 reveals the presence of an apicoplast in each. Microscopic analysis of the contents in test tube 5 reveals the presence of one large nucleus and several small nuclei in each organism. Figure 25.1 The next few questions refer to the following description and Figure 25.1. -Test tube 3 contains

You are given the task of designing an aquatic protist that is a primary producer. It cannot swim on its own, yet must stay in well-lit surface waters. It must be resistant to physical damage from wave action. It should be most similar to a(n)

The oldest fossil eukaryote that can be resolved taxonomically is of

An individual mixotroph loses its plastids, yet continues to survive. Which of the following most likely accounts for its continued survival?

According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate?

Which group is incorrectly paired with its description?

Green algae differ from land plants in that many green algae

The genome of modern chloroplasts is roughly 50% of the size of the genome of the cyanobacterium from which it is thought to have been derived. In comparison, the genome of P. chromatophora's cyanelle is only slightly reduced relative to the size of the genome of the cyanobacterium from which it is thought to have been derived. What is a valid hypothesis that can be drawn from this comparison?