Chapter 18 - Protists

Supergroups is a way of classifying organisms that share a common evolutionary lineage, whether those organisms are microorganisms or multicellular.

True

Water molds are unlike fungi in that water molds have diploid filaments and cell walls containing cellulose, whereas fungi have haploid filaments and cell walls containing chitin.

True

Within the typical sexual reproduction of green algae, the sporophyte form of the protist is A) 2n, or diploid, because the sporophyte follows fertilization, growing and differentiating through numerous cell cycles. B) 1n, or haploid, because the sporophyte follows meiosis. C) limited to the DNA found within the chloroplasts, because the sporophyte is a dormant form of the protist. D) reproduced through mitosis, after the zygote single cell has formed. E) None of the answer choices are correct.

A) 2n, or diploid, because the sporophyte follows fertilization, growing and differentiating through numerous cell cycles.

Which of the following best states the hypothesis tested by Abrahams and Townsend while investigating the natural selection of copepods that avoid predation of bioluminescent dinoflagellates? A) Copepods that avoid bioluminescent dinoflagellates are less likely to be eaten by predators than copepods that feed on the bioluminescent dinoflagellates. B) Bioluminescent flagellates benefit from selection of flashing, because it startles the copepods. C) The bioluminescent dinoflagellates produce enough light that they can also photosynthesize at night, harming the copepods. D) The light emitted by bioluminescent dinoflagellates is of sufficient wavelength and energy to be dangerous to feeding copepods. E) None of the answer choices are correct.

A) Copepods that avoid bioluminescent dinoflagellates are less likely to be eaten by predators than copepods that feed on the bioluminescent dinoflagellates.

DNA sequence evidence suggests that plants, fungi, and animals arose from different lineages of unicellular protists. This suggests which of the following? A) Protists arose before the other three kingdoms. B) Early ancestorsto plants, fungi, and animals could interbreed. C) Multicellularorganisms only arose once in evolutionary history. D) All unicellularorganisms are now extinct. E) The animal, plant, and fungal kingdoms contain some living single-celled organisms.

A) Protists arose before the other three kingdoms.

One reason that malaria continues to be the world's most significant infectious disease is because Plasmodium falciparum continues to develop resistance to the drugs that have been used to treat malaria. Which of the following statements best explains the reason for this resistance? A) Some Plasmodium falciparum have preexisting mutations that make them resistant to antimalarial drugs. B) Some mosquitoes have preexisting mutations that make them resistant to antimalarial drugs. C) Some people have preexisting mutations that make them resistant to antimalarial drugs. D) The antimalarial rugs cause mutations to occur in Plasmodium falciparum. E) The antimalarial rugs cause mutations to occur in the mosquito.

A) Some Plasmodium falciparum have preexisting mutations that make them resistant to antimalarial drugs.

Organisms, such as forams, move by pseudopodia and feed by phagocytosis. These organisms are classified as __________ protozoa. A) amoeboid B) apicomplexan C) ciliated D) flagellated E) bimodal

A) amoeboid

Which group of algae consists of the largest most complex protists? A) brown algae B) diatoms C) red algae D) golden algae E) green algae

A) brown algae

From which source is it thought that chloroplasts in algae originated? A) cyanobacteria B) aerobic bacteria C) anaerobic bacteria D) photosynthetic viruses E) aerobic fungi

A) cyanobacteria

Silica walls are characteristic of A) diatoms. B) euglenoids. C) red algae. D) brown algae. E) slime molds

A) diatoms.

The organism Plasmodium falciparum causes malaria. In which type(s) of human cell(s) does it infect and grow? A) liver and red blood cells B) liver cells C) red blood cells D) intestinal cells E) liver and intestinal cells

A) liver and redblood cells

In ciliates, the function of a contractile vacuole is to A) maintain water balance in the cell. B) store nutrients . C) provide movement. D) store toxins. E) All of the answer choices are correct.

A) maintain water balance in the cell.

Malaria is caused by Plasmodium falciparum, a nonmotile protist that contains a cluster of microtubules at one end of the cell. Once injected into the bloodstream, these microtubules are used to attach to red blood cells. In areas of the world where malaria is endemic, people have a relatively high incidence of the allele for A) sickle cell. B) blue eyes. C) cysticfibrosis. D) mental disabilities. E) hemophilia.

A) sickle cell.

The correct sequence in body forms and life stages occurring in alternation of generations in green algae protists is A) sporophyte - meiosis division - spores - mitotic division - gametophytes - gametes - fertilization - zygote. B) sporophyte - meiosis division - mitotic division - spores - gametophytes - fertilization - gametes - zygote. C) gametes - meiosis division - spores - mitotic division - gametophytes - sporophyte - fertilization - zygote. D) gametophytes - gametes - sporophyte - meiosis division - spores - mitotic division - fertilization - zygote. E) gametophytes - gametes - sporophyte - mitotic division - spores - meiosis division - fertilization - zygote.

A) sporophyte - meiosis division - spores - mitotic division - gametophytes - gametes - fertilization - zygote.

Which of the following is not a characteristic of protists? A)They are prokaryotes. B)They have a nucleus. C)They have membrane-bounded organelles. D)They are a very diverse group of organisms. E)All of the answer choices describe characteristics of protists.

A)They are prokaryotes.

Diatoms are a type of algae with a hard silica cell wall. Which of the following structures would you expect to find directly underneath the cell wall? A) a cell wall B) a plasma membrane C) a nucleus D) a chloroplast E) a mitochondrion

B) a plasma membrane

African sleeping sickness is caused by Trypanosoma brucei, a unicellular flagellated protist that infects red blood cells after being injected into the bloodstream. Trypanosoma brucei is which of the following? A) an alga B) a protozoan C) a slime mold D) a diatom E) an apicomplexan

B) a protozoan

Foraminiferan shells are made of A) cellulose. B) calcium carbonate. C) chitin. D) peptidoglycan. E) silica.

B) calcium carbonate.

Ciliate cells have a food vacuole that surrounds and transports each captured meal inside the cell. Based on this information, it can be inferred that ciliate cells are A) autotrophic. B) heterotrophic. C) parasitic. D) both heterotrophic and autotrophic. E) a heterotroph and parasitic.

B) heterotrophic.

In malaria, Plasmodium falciparum grow inside human cells. Because they use the human cells for food, they are classified as which of the following? A) autotrophs B) heterotrophs C) phototrophs D) heterotrophs andautotrophs E) autotrophs andphototrophs

B) heterotrophs

Malaria is caused by Plasmodium falciparum, a nonmotile protist that contains a cluster of microtubules at one end of the cell. Once injected into the bloodstream, these microtubules are used to attach to red blood cells. Malaria is transmitted by the bite of a A) tsetse fly. B) mosquito. C) sand fly. D) kissing bug. E) housefly.

B) mosquito.

Some protozoa have cell structures that are formed as temporary extensions of the cell membrane, allowing the cell to detect and respond to their environment, and to catch and engulf food. These extensions are called A) flagella. B) pseudopodia. C) cilia. D) antennae. E) spikes.

B) pseudopodia.

Chlamydomonas is unicellular and uses chlorphyll a and b for photosynthesis. Based on these characteristics, Chlamydomonas is classified as A) a slime mold B) an apicomplexan C) a diatom D) a protozoan E) a green alga

E) a green alga

Dictyostelium discoideum is an unusual organism, one that straddles the boundary between the unicellular and the multicellular. Its feeding phase consists of individual amoeba-like cells that move independently, feeding on bacteria by phagocytosis. When the food runs out, cells begin to aggregate into a multicellular structure that migrates toward light. The cells then differentiate into a base, stalk, and spores. Only the spores survive to colonize a new habitat. What is the advantage of forming spores? A) The spores will eat the other cells. B) The spores are photosynthetic. C) Spores are smaller and can be easily transported to new habitats. D) Spores can mate with other species. E) Spores have flagella and can swim to new habitats.

C) Spores are smaller and can be easily transported to new habitats.

Which group of protists consumes CO2 and produces O2 for much of Earth, serving as the base of food webs in lakes, streams, and the oceans? A) amoebas B) slime molds C) algae D) protozoans E) radiolarians

C) algae

Some euglenoids have chloroplasts and can perform phagocytosis. These euglenoids would be considered which of the following? A) autotrophs B) heterotrophs C) autotrophs and heterotrophs D) detritovores E) heterotrophs and detritovores

C) autotrophs and heterotrophs

A woman was told by her doctor that while she is pregnant, she might need assistance with her cats so she would not contract toxoplasmosis. What is the mechanism of transmission of toxoplasmosis? A) flea bites transmit the organism B) scratches frominfected claws C) exposure toinfected cat feces D) infection fromsaliva E) infection from mice the cat may bring into the house

C) exposure toinfected cat feces

A protective layer made of rigid or elastic protein strips surrounding the cell membrane of euglenoids is a A) flagellum. B) cell wall. C) pellicle. D) pseudopodium. E) gullet.

C) pellicle.

The Irish potato famine in the mid-1840s was caused by a heterotrophic protist, Phytophthora infestans, which caused widespread infection of potato plants. Phythophthora infestans is classified as a __________ and was able to infect so many potatoes because __________. A) red alga; able to perform photosynthesis, which allowed its cells to spread easily from potato to potato. B) diatom; of its silica shell which allowed it to survive the soil conditions in which potatoes are grown. C) water mold; rainy weather was conducive to its growth and dispersal through the potato fields. D) protozoon; it was able to use its flagella to swim in the rainwater from potato to potato. E) ciliate; its pellicle allowed it to easily burrow into a potato and consume all the starch.

C) water mold; rainy weather was conducive to its growth and dispersal through the potato fields.

Based on the theory of endosymbiosis, which of the following would you expect to find in a chloroplast? A) cellulose B) a nucleus C) silica D) DNA E) a mitochondrion

D) DNA

From which source is it thought that mitochondria in algae originated? A) cyanobacteria B) anaerobic bacteria C) photosynthetic viruses D) aerobic bacteria E) Algae don't have mitochondria.

D) aerobic bacteria

While on a field trip near the ocean coastline, you visit a company that harvests a jellylike substance from red algae. The substance can be used as a culturing medium for microorganisms and a thickener in ice cream and yogurt. This jellylike substance is called A) red ooze. B) carrageenan. C) gelatin. D) agar. E) algin.

D) agar.

Entamoeba histolytica moves using pseudopodia, can only feed by phagocytosis, and is unicellular. Entamoeba histolytica is classified as A) a plasmodial slime mold. B) a flagellated protozoan. C) a green alga. D) an amoeboid protozoan. E)a red alga

D) an amoeboid protozoan.

Euglena and dinoflagellates have chloroplasts and flagella. This indicates they are A) photosynthetic. B) motile. C) multicellular. D) photosynthetic and motile. E) multicellular and motile.

D) photosynthetic and motile.

In the experiment studying bioluminescence and the predation of copepods by fish, a control group of jars with bioluminescent dinoflagellates experienced a higher predation rate of copepods by stickleback fish than in the jars with nonbioluminescent dinoflagellates. This provided significant evidence that A) bioluminescent dinoflagellates are less likely to be eaten by copepods than are nonbioluminescent dinoflagellates. B) copepods that would eat dinoflagellates benefit from fleeing when the protists bioluminesce. C) natural selection has favored the survival of dinoflagellates that can emit light in flashes when disturbed. D) natural selection has favored the survival of copepods that move rapidly away from flashing bioluminescent dinoflagellates. E) All of the answer choices are correct.

E) All of the answer choices are correct.

Trichonympha is a unicellular flagellated protist that lives within termites and allows the termite to be able to "digest" wood. Trichonympha is which of the following? A) an apicomplexan B) an alga C) a slime mold D) a diatom E) a protozoan

E) a protozoan

A substance produced by brown algae that is used as an emulsifying and thickening agent in many foods and other products is A) agar. B) red ooze. C) gelatin. D) carrageenan. E) algin.

E) algin.

Malaria is caused by Plasmodium falciparum, a nonmotile protist that contains a cluster of microtubules at one end of the cell. Based on these characteristics, Plasmodium falciparum is classified as A) a protozoan. B) an alga. C) a slime mold. D) a diatom. E) an apicomplexan.

E) an apicomplexan.

Where in a diatom would you find its yellowish photosynthetic pigment? A) in the plasma membrane B) in the cytoplasm C) in the cell wall D) in the nucleus E) in chloroplasts

E) in chloroplasts

The process whereby a protist eats by producing cellular extensions that engulf and absorb food particles is known as A) chemotaxis. B) karyokinesis. C) pseudopodia. D) cytokinesis. E) phagocytosis.

E) phagocytosis.

All protists are single-celled.

False

Alternation of generations means having alternating, unicellular haploid and diploid phases in a life cycle.

False

Biologists have a good understanding of how multicellularity evolved.

False

Genetic evidence suggests that multicellular organisms arose from different lineages of unicellular protists.

True

Golden algae, diatoms, and brown algae contain yellowish pigments.

True

It may make more sense to classify protists and all other eukaryotes in "supergroups" rather in kingdoms because the protists do not all share a common ancestor.

True

Protists can be autotrophs.

True

Protists can be heterotrophs.

True

Slime molds may exist as either single amoeboid cells or large masses of cells that behave as one multicellular organism.

True