Question 1

Algae were incorporated into several other groups of protists through secondary endosymbiosis.
A)1, 2
B)3, 4
C)1, 6
D)2, 6

Accepted Answer

The answer of Algae were incorporated into several other groups...

Question 2

Mitochondria and then chloroplasts evolved through primary endosymbiosis.

Accepted Answer

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Question 3

According to the figure, green alga resulted from ________, and Euglena resulted from ________. 
A)primary endosymbiosis; both primary and secondary endosymbiosis
B)primary endosymbiosis; primary endosymbiosis
C)both primary and secondary endosymbiosis; secondary endosymbiosis only
D)secondary endosymbiosis only; primary endosymbiosis

Accepted Answer

According to the figure, green alga resulted from primary endosymbiosis because it has a chloroplast with a double membrane, which suggests that it was engulfed by a host cell. Euglena resulted from both primary and secondary endosymbiosis as it has a chloroplast with three or four membranes, which suggests that it underwent both primary and secondary endosymbiosis.

Question 4

You are studying a mini-ecosystem that you created from samples of lake water, plants, and sediment. Your teacher tells you to drop about 10 sesame seeds on the top of the water because they will attract some interesting organisms. One week later, you see that the seeds are surrounded by white fuzz that is extending off of the seeds, and you conclude that the decomposing seeds have been colonized by
A)diatoms.
B)brown algae.
C)unikonts.
D)water molds.

Accepted Answer

The white fuzz surrounding the seeds is most likely a type of mold, which fits the description of water molds (also known as Oomycetes). Water molds decompose organic material in aquatic environments and are common in freshwater ecosystems. Diatoms and brown algae are aquatic photosynthetic organisms, and unikonts is a broad grouping of eukaryotic organisms that includes animals, fungi, and some protists. None of these groups are likely to be responsible for the observed growth on the sesame seeds.

Question 5

The bacteria Pseudomonas aeruginosa produces a protein that is secreted into its environment. The protein inhibits synthesis of elongation factor 2 (another protein)in humans. This effect may sound dangerous, but it has been considered as a possible treatment for hepatitis B. The protein produced by P. aeruginosa is a/an ________.
A)endotoxin
B)exotoxin
C)biological weapon
D)biofilm

Accepted Answer

The protein produced by P. aeruginosa is inhibiting the synthesis of elongation factor 2, which is a characteristic of exotoxins. Endotoxins are found in the cell wall of Gram-negative bacteria and can cause an immune response that leads to inflammation and fever. Biological weapons are intentionally developed to harm humans, which is not the case with this protein. Biofilm is a community of microorganisms that adhere to each other and to surfaces.

Question 6

Which of the following statements regarding Ulva is true?
A)Ulva, a green algae, resembles land plants because it produces diploid gametes.
B)Ulva, a brown algae, has a complex life cycle with diploid body cells and haploid gametes.
C)Ulva, a green algae, has a complex life cycle with diploid body cells and haploid gametes.
D)Ulva, a green algae, has a complex life cycle with alternation between multicellular diploid and haploid generations.

Accepted Answer

Ulva, a green algae, exhibits alternation of generations, meaning it has both multicellular diploid (sporophyte) and haploid (gametophyte) stages in its life cycle.

Question 7

Some current research efforts are investigating whether or not ________, a group of prokaryotes with the ability to produce oxygen as a by-product of photosynthesis, can be used as a source of renewable energy by converting sunlight into electricity.
A)chlamydias
B)spirochetes
C)proteobacteria
D)cyanobacteria

Accepted Answer

Cyanobacteria are the prokaryotes with the ability to produce oxygen as a by-product of photosynthesis, making them a potential source of renewable energy through the conversion of sunlight into electricity. Chlamydias and spirochetes do not have this ability, and while some proteobacteria can carry out photosynthesis, they typically do not produce significant amounts of oxygen as a by-product.

Question 8

Compost piles create an intense heat source and would therefore be suitable environments for ________.
A)extreme thermophiles
B)extreme halophiles
C)methanogens
D)proteobacteria

Accepted Answer

Compost piles can reach temperatures that exceed 140°F (60°C), which is an ideal temperature range for extreme thermophiles, organisms that thrive in very high-temperature environments. Methanogens are organisms that produce methane and are often found in anaerobic environments such as swamps and marshes. Proteobacteria is a large and diverse group of bacteria that includes many different types of bacteria, and extreme halophiles are organisms that thrive in extremely salty environments. None of these are well-suited for the high-temperature environment of a compost pile.

Question 9

The famous pink-colored sand of Bermuda's beaches is due to crushed shells of ________, marine organisms with tests (porous shells)made of organic material hardened by calcium carbonate.
A)radiolarians
B)green algae
C)foraminifera
D)lobsters

Accepted Answer

The description matches that of foraminifera, which have porous shells made of organic material and calcium carbonate. Radiolarians do have tests made of silica, but they do not typically create pink-colored sand. Green algae and lobsters do not have tests at all, nor do they contribute significantly to the makeup of beach sand.

Question 10

Alginates are used in many everyday products, including toothpaste and soap. When added to water, they form a thick gel that binds or emulsifies liquids. Alginates come from a group of multicellular stramenopiles that have one pigment that masks all others and therefore gives these organisms a distinctive, dark color. Alginates are derived from
A)green algae.
B)brown algae.
C)water molds.
D)dinoflagellates.

Accepted Answer

Alginates are predominantly derived from brown algae, specifically from the cell walls.

Question 11

Protozoans were incorporated into several other groups of protists through secondary endosymbiosis.

Accepted Answer

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Question 12

Mitochondria evolved through primary endosymbiosis

Accepted Answer

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Question 13

Someone diagnosed with meningitis has inflamed membranes that cover and protect the brain and spinal cord. Meningitis is a result of pathogenic gram-negative bacteria that cause extreme infections when their bacterial cell wall dies and lipopolysaccharide (a lipid and polysaccharide)is released. The lipopolysaccharide is an example of a/an
A)endotoxin.
B)exotoxin.
C)stomach microbiota.
D)parasite.

Accepted Answer

Lipopolysaccharide is a component of the cell wall of gram-negative bacteria and is released when the bacterial cell dies. It acts as an endotoxin which triggers an intense immune response leading to inflammation and fever, among other symptoms, in the host.

Question 14

Which stage of the life cycle shown is the sporophyte? 
A)stage A
B)stage B
C)stage C
D)stage D

Accepted Answer

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Question 15

Choose two of the following events in protist evolution and then put them in the correct order in which they occur according to current science.

Accepted Answer

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Question 16

Some white blood cells are able to surround and ingest bacteria. Which of the following would you expect to see as part of the blood cell structure?
A)secondary cell walls
B)flagella
C)pseudopodia
D)cilia

Accepted Answer

Pseudopodia are temporary projections of the cell membrane that allow for movement and engulfment of particles, making them the best choice for describing the process of a white blood cell surrounding and ingesting bacteria. Secondary cell walls, flagella, and cilia are not typically found in white blood cells.

Question 17

If you place an organism classified as a photoautotroph at the bottom of a lake and later see that it is able to acquire nutrients from dead plant material, you can conclude the photoautotroph is actually a
A)photoheterotroph.
B)chemoautotroph.
C)chemoheterotroph.
D)mixotroph.

Accepted Answer

A photoautotroph is an organism that can produce its own food using sunlight and carbon dioxide. If it is also able to obtain nutrients by consuming dead plant material, it is considered a mixotroph. A photoheterotroph is an organism that can produce its own food using light but also needs to obtain nutrients from organic sources. A chemoautotroph can produce its own food using inorganic chemicals as an energy source, while a chemoheterotroph obtains both energy and nutrients from organic sources.

Question 18

Chloroplasts evolved through secondary endosymbiosis.

Accepted Answer

The answer of Chloroplasts evolved through secondary endosymbiosis....

Question 19

Dunaliella salina is a bacterium that is able to live in aqueous solutions with such high salt concentrations that the salt cannot fully dissolve. D. salina is an example of a/an
A)extreme thermophile.
B)extreme halophile.
C)methanogen.
D)proteobacteria.

Accepted Answer

Dunaliella salina is an extreme halophile, meaning it is a bacterium that thrives in environments with high salt concentrations.

Question 20

Chloroplasts and then mitochondria evolved through primary endosymbiosis.

Accepted Answer

The answer of Chloroplasts and then mitochondria evolved through primary...

Quiz 16: Microbial Life: Prokaryotes and Protists

Algae were incorporated into several other groups of protists through secondary endosymbiosis.

Mitochondria and then chloroplasts evolved through primary endosymbiosis.

According to the figure, green alga resulted from , and Euglena resulted from .

Which of the following statements regarding Ulva is true?

Some current research efforts are investigating whether or not ________, a group of prokaryotes with the ability to produce oxygen as a by-product of photosynthesis, can be used as a source of renewable energy by converting sunlight into electricity.

Compost piles create an intense heat source and would therefore be suitable environments for ________.

The famous pink-colored sand of Bermuda's beaches is due to crushed shells of ________, marine organisms with tests (porous shells) made of organic material hardened by calcium carbonate.

Protozoans were incorporated into several other groups of protists through secondary endosymbiosis.

Mitochondria evolved through primary endosymbiosis

Which stage of the life cycle shown is the sporophyte?

Choose two of the following events in protist evolution and then put them in the correct order in which they occur according to current science.

Some white blood cells are able to surround and ingest bacteria. Which of the following would you expect to see as part of the blood cell structure?

If you place an organism classified as a photoautotroph at the bottom of a lake and later see that it is able to acquire nutrients from dead plant material, you can conclude the photoautotroph is actually a

Chloroplasts evolved through secondary endosymbiosis.

Dunaliella salina is a bacterium that is able to live in aqueous solutions with such high salt concentrations that the salt cannot fully dissolve. D. salina is an example of a/an

Chloroplasts and then mitochondria evolved through primary endosymbiosis.