Exam 28: Protists

Theoretically, P.bursaria can obtain zoochlorella either vertically (via the asexual reproduction of its mother cell)or horizontally (by ingesting free-living Chlorella from its habitat). Consider a P. bursaria cell containing zoochlorellae, but whose habitat lacks free-living Chlorella. If this cell subsequently undergoes many generations of asexual reproduction, if all of its daughter cells contain roughly the same number of zoochlorellae as it had originally contained, and if the zoochlorellae are all haploid and identical in appearance, then what is True?

The following questions refer to the description and Table 28.1 below. Diatoms are encased in Petri-plate-like 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. Below are data concerning the density (specific gravity) of various components of diatoms, and of their environment. Table 28.1: Specific Gravities of Materials Relevant to Diatoms Material Specific Gravity (//) Pure water 1000 Seawater 1026 Hydrated silica 2250 Liquid laminarin 1500 Diatom oil 910 -A certain unicellular eukaryote has a siliceous (glasslike)shell and autotrophic nutrition. To which group does it belong?

Which term most accurately describes the nutritional mode of healthy P. bursaria?

In life cycles with an alternation of generations, multicellular haploid forms alternate with

The Irish potato famine was caused by an organism that belongs to which group?

Which of the following is not characteristic of ciliates?

Which of these are actual mutualistic partnerships that involve a protist and a host organism?

A biologist discovers a new unicellullar organism that possesses more than two flagella and two small, but equal-sized, nuclei. The organism has reduced mitochondria (mitosomes), no chloroplasts, and is anaerobic. To which clade does this organism probably belong?

The following questions refer to the description and Table 28.1 below. Diatoms are encased in Petri-plate-like 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. Below are data concerning the density (specific gravity) of various components of diatoms, and of their environment. Table 28.1: Specific Gravities of Materials Relevant to Diatoms Material Specific Gravity (//) Pure water 1000 Seawater 1026 Hydrated silica 2250 Liquid laminarin 1500 Diatom oil 910 -Which of the following produce the dense glassy ooze found in certain areas of the deep-ocean floor?

The following questions refer to the description and Table 28.1 below. Diatoms are encased in Petri-plate-like 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. Below are data concerning the density (specific gravity) of various components of diatoms, and of their environment. Table 28.1: Specific Gravities of Materials Relevant to Diatoms Material Specific Gravity (//) Pure water 1000 Seawater 1026 Hydrated silica 2250 Liquid laminarin 1500 Diatom oil 910 -Water's density and, consequently, its buoyancy decrease at warmer temperatures. Based on this consideration and using data from Table 28.1, at which time of year should one expect diatoms to be storing excess calories mostly as oil?

In test tube 1, you observe an organism feeding. Your sketch of the organism looks very similar to Figure 28.1. 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 tubes 2, 4, and 5 reveals the presence of permanent, membrane-bounded sacs just under the plasma membrane. Microscopic analysis of organisms in tube 4 reveals the presence of an apicoplast in each. Microscopic analysis of the contents in tube 5 reveals the presence of one large nucleus and several small nuclei in each organism. Figure 28.1 You are given five test tubes, each containing an unknown protist, and your task is to read the description below and match these five protists to the correct test tube. -Test tube 2 contains

The following questions refer to the description and Table 28.1 below. Diatoms are encased in Petri-plate-like 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. Below are data concerning the density (specific gravity) of various components of diatoms, and of their environment. Table 28.1: Specific Gravities of Materials Relevant to Diatoms Material Specific Gravity (//) Pure water 1000 Seawater 1026 Hydrated silica 2250 Liquid laminarin 1500 Diatom oil 910 -Using dead diatoms to "pump" CO? to the seafloor is feasible only if dead diatoms sink quickly. Consequently, application of mineral fertilizers, such as iron, should be most effective at times when diatom

Which term accurately describes the behavior of Paramecium species that lack zoochlorellae in an aquarium with light coming from one side only?

In test tube 1, you observe an organism feeding. Your sketch of the organism looks very similar to Figure 28.1. 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 tubes 2, 4, and 5 reveals the presence of permanent, membrane-bounded sacs just under the plasma membrane. Microscopic analysis of organisms in tube 4 reveals the presence of an apicoplast in each. Microscopic analysis of the contents in tube 5 reveals the presence of one large nucleus and several small nuclei in each organism. Figure 28.1 You are given five test tubes, each containing an unknown protist, and your task is to read the description below and match these five protists to the correct test tube. -Test tube 4 contains

The following questions refer to the description and Table 28.1 below. Diatoms are encased in Petri-plate-like 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. Below are data concerning the density (specific gravity) of various components of diatoms, and of their environment. Table 28.1: Specific Gravities of Materials Relevant to Diatoms Material Specific Gravity (//) Pure water 1000 Seawater 1026 Hydrated silica 2250 Liquid laminarin 1500 Diatom oil 910 -A gelatinous seaweed that grows in shallow, cold water and undergoes heteromorphic alternation of generations is most probably what type of alga?

Which of the following statements concerning living phytoplanktonic organisms are True? 1) They are important members of communities surrounding deep-sea hydrothermal vents. 2) They are important primary producers in most aquatic food webs. 3) They are important in maintaining oxygen in Earth's seas and atmosphere. 4) They are most often found growing in the sediments of seas and oceans. 5) They can be so concentrated that they affect the color of seawater.

The following questions refer to the description and Table 28.1 below. Diatoms are encased in Petri-plate-like 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. Below are data concerning the density (specific gravity) of various components of diatoms, and of their environment. Table 28.1: Specific Gravities of Materials Relevant to Diatoms Material Specific Gravity (//) Pure water 1000 Seawater 1026 Hydrated silica 2250 Liquid laminarin 1500 Diatom oil 910 -Some protists, formerly united as the "amitochondriate" clade, have recently been shown to be rather diverse. Some of them possess neither mitochondria nor mitochondrial genes (and have been classified as fungi). Others possess no mitochondria, but do have mitochondrial genes in their nuclear genome. Still others have modified mitochondria (viz. mitosomes or hydrogenosomes). Which statement(s)represent(s)consequences of these recent findings? 1) The amitochondriates do not comprise a True clade. 2) The "amitochondriate hypothesis" concerning the root of the eukaryotic tree has been strengthened. 3) Just as there is a diversity of cyanobacterial descendants among eukaryotes, so too is there a diversity of alpha-proteobacterial descendants among the eukaryotes. 4) If the amitochondriate organisms continued to be recognized as a taxon, this taxon would be polyphyletic. 5) Horizontal gene transfer involving mitochondrial genes has occurred in some amitochondriate organisms.

The following questions refer to the description and Table 28.1 below. Diatoms are encased in Petri-plate-like 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. Below are data concerning the density (specific gravity) of various components of diatoms, and of their environment. Table 28.1: Specific Gravities of Materials Relevant to Diatoms Material Specific Gravity (//) Pure water 1000 Seawater 1026 Hydrated silica 2250 Liquid laminarin 1500 Diatom oil 910 -A biologist discovers an alga that is marine, multicellular, and lives at a depth reached only by blue light. This alga probably belongs to which group?

Which two genera have members that can evade the human immune system by frequently changing their surface proteins? 1) Plasmodium 2) Trichomonas 3) Paramecium 4) Trypanosoma 5) Entamoeba

Which of these precautions would have been most important to insuring the validity of the results?