Deck 11: Unicellular Eukaryotes

Question 1

Which of the following is NOT a correct description of how the cytoplasm moves in pseudopodia?

A) Actin filaments become cross-linked by an actin-binding protein forming a semisolid gel-like state called ectoplasm.
B) The nucleus codes for each movement using DNA and protein formation.
C) Interaction with lipids in the cell membrane releases actin subunits and allows them to polymerize into actin microfilaments.
D) Near the edge of the gel, calcium ions activate an actin-binding protein that releases the actin filaments from the gel.
E) Myosin pulling on the edge of the gel causes contraction that forces endoplasm toward the hyaline cap.

Answer 1

B

Question 2

What are long,thin pseudopodia supported by axial rods of microtubules called?

A) lobopodia
B) filopodia
C) axopodia
D) reticulopodia
E) actinopodia

Answer 2

C

Question 3

The most likely mechanism for removing excess water by contractile vacuoles is

A) simple osmosis of water across the cell membrane.
B) differential fluid pressure.
C) reverse osmosis.
D) a proton pump that also pulls water into the vacuole.
E) an ampulla that forms suction.

Answer 3

D

Question 4

The protozoan dictyosome is called what in other eukaryotes?

A) ribosome
B) mitochondrium
C) endoplasmic reticulum
D) golgi apparatus
E) plastid

Question 5

Compared to metazoans,what is the correct perspective on cellular organization of unicellular eukaryotes?

A) They are comparatively simpler with fewer structures or organelles than the metazoans.
B) They are more limited in their organization and function than a metazoan cell.
C) They are equivalent, no more complex nor simpler.
D) They are complex and must accomplish within a cell the functions that several specialized cells accomplish in metazoa.
E) None of the choices are correct.

Question 6

Which organelle was once an independent aerobic prokaryote engulfed by an anaerobic prokaryote?

A) nucleus
B) mitochondrion
C) plastid
D) ribosome
E) endoplasmic reticulum

Question 7

What is the specific structure in ciliates that serves as the site of expulsion for wastes called?

A) phagosome
B) lysosome
C) cytostome
D) cytoproct
E) paramylon body

Question 8

Nutrition in unicellular eukaryotes is best described as

A) autotrophic.
B) heterotrophic.
C) saprozoic.
D) All of the choices are correct.
E) None of the choices are correct.

Question 9

When a nucleus has chromatin that is clumped,leaving clear areas within the nucleus,the appearance is described as

A) pellicular.
B) vesicular.
C) micronuclear.
D) kinetosomic.
E) spicular.

Question 10

Which structure is NOT correctly linked to the type of movement or podial function?

A) Axoneme-actin-binding protein that keeps ectoplasm from gelling
B) Axopodia-thin rods of microtubules
C) Lobopodia-flow of both endoplasm and ectoplasm
D) Filopodia-thin extensions of only ectoplasm
E) Reticulopodia-a thin net-like mesh

Question 11

What is the name of the mouth structure found at the end of the oral groove in a Paramecium ciliate?

A) phagosome
B) lysosome
C) cytostome
D) cytoproct
E) paramylon body

Question 12

Which unicellular eukaryote is NOT correctly linked to the type of movement structure it possesses?

A) Amoeboids-pseudopodia
B) Ciliates-cilia
C) Dinoflagellates-flagella
D) Paramecium-flexibility of the pellicle
E) Apicomplexa-reticulopodia

Question 13

What is the function of the contractile vacuole in protozoa?

A) water balance
B) digestion
C) locomotion
D) excretion of nitrogen wastes
E) respiration

Question 14

What is found at the base of every flagellum or cilium?

A) a kinetosome
B) a kinetid
C) an axopod
D) a kinetoplast
E) a lobopod

Question 15

The most correct usage of the term "protozoa" is as a(n)

A) phylum.
B) class.
C) separate kingdom.
D) synonym for Protista.
E) informal cluster of groups with complicated and uncertain phyletic relationships.

Question 16

Which of the following is/are correct descriptions of unicellular eukaryote characteristics?

A) As primitive organisms, they are restricted to asexual reproduction.
B) No germ layers are ever formed.
C) They are all aquatic.
D) When found in other organisms, they are typically parasitic or pathogenic.
E) They all lack symmetry.

Question 17

The distinction between phagotrophs (or holozoic feeders)and osmotrophs (or saprozoic feeders)is a difference between

A) eating living and eating dead organic material.
B) diffusion of food across the membrane versus engulfing food in a vacuole.
C) ingesting visible particles or organisms versus ingesting dissolved substances, sometimes from dead organisms.
D) producing your own food versus using the chemical bonds in food molecules made by others.
E) direct transport versus indirect transport of food molecules.

Question 18

Which is NOT a correct description of a member of a protozoan group?

A) usually motile
B) development involves an embryonic stage
C) small; about 21,000 micrometers in size
D) usually unicellular; if multicellular, without somatic differentiation
E) All of the choices are correct

Question 19

Which of the following represents the arrangement of microtubules in axonemes of cilia?

A) nine peripheral triplets of microtubules
B) nine peripheral pairs of microtubules plus one central pair
C) nine peripheral triplets of microtubules plus one central pair
D) nine peripheral pairs of microtubules plus two central pairs
E) three peripheral pairs of microtubules and no central pairs

Question 20

Ectoplasm

A) provides the vital force of life.
B) is cytoplasm that is outside the cell membrane of protozoans.
C) is only found in parasitic amebas.
D) is only found in spores of parasitic protozoans.
E) contrasts with endoplasm; both ectoplasm and endoplasm are cytoplasmic components.

Question 21

The early development of a globular colony (with flagella inward)that then turns inside-out (with flagella outward)is

A) called an undulating membrane and is common among ciliates.
B) a pseudoplasmodium and only found in protozoans.
C) called inversion, and it is very common in early development in many animal groups.
D) called inversion, and it is very rare among animals, only occurring in colonial flagellates and sponges.
E) called reverse gastrulation and it is very rare among animals.

Question 22

"Red tides" are caused by massive blooms of

A) sporozoans.
B) dinoflagellates.
C) Euglena.
D) ciliates.
E) Plasmodia.

Question 23

Which protozoan is used to test hypotheses of how multicellular organisms arose from their closest unicellular relatives?

A) microsporidians
B) choanoflagellates
C) opalinids
D) retortamonads
E) kinetoplastans

Question 24

When the haploid cells or pronuclei are borne in equal-sized cells that look alike,they are called what?

A) anisogametes
B) syngametes
C) autogametes
D) unigametes
E) isogametes

Question 25

The macronucleus of a ciliate elongates,constricts and divides without going through the mitotic stages in a process called what?

A) amitosis
B) budding
C) syngamy
D) autogamy
E) sporogony

Question 26

Some organisms undergo meiosis to produce gametes that fuse to form a zygote internally without leaving the organism.What is the effect of this process on genetic diversity of the offspring?

A) The offspring would be identical clones of the parent.
B) The offspring could vary from the parent but there would be less genetic variation because this is inbreeding.
C) The offspring would vary from the parent because it would produce different recombinations of each chromosome pair.
D) The offspring would become more and more genetically diverse each generation.
E) None of the choices are correct.

Question 27

The strange case of organisms that undergo meiosis after fertilization and live out their adult life in the haploid state is a case of what?

A) syngamy
B) zygotic meiosis
C) gametic meiosis
D) autogamy
E) conjugation

Question 28

Most of the time,although they usually have other options,protozoans reproduce by

A) conjugation.
B) asexual cell division.
C) fusion of gametes.
D) parthenogenesis.
E) autogamy.

Question 29

Usually we expect fission to produce two cells from one,but in Sporozoea and some Sarcodina,multiple fission of the nucleus is followed by rapid division of cytoplasm,releasing many new individuals immediately in a process called what?

A) amitosis
B) budding
C) syngamy
D) autogamy
E) sporogony

Question 30

A protozoan with both plant-like photosynthesis and animal-like motility is most likely a

A) sporozoan.
B) dinoflagellate.
C) euglenoid.
D) zooflagellate.
E) ciliate.

Question 31

Protective cysts are triggered by what?

A) food shortages
B) drying out
C) decreased oxygen
D) merely being the next stage in a regular life cycle
E) all of the choices are correct

Question 32

Protist reproduction

A) is always asexual and usually binary fission.
B) is always sexual with the adults being haploid.
C) is always sexual with the adults being diploid.
D) is always sexual with alternation of haploid and diploid generations.
E) may be asexual or any of the above sexual cycles.

Question 33

Cilia or flagella are resorbed and the Golgi apparatus secretes wall material during

A) formation of a contractile vacuole.
B) intermediary meiosis.
C) conjugation.
D) pseudopod streaming.
E) encystment.

Question 34

Members of Euglena have starch-like food storage material in the form of what?

A) stigmata
B) chloroplasts
C) paramylon bodies
D) flagellar bodies
E) kinetosomes

Question 35

What happens during conjugation in most ciliates?

A) Haploid micronuclei are exchanged.
B) Macronuclei are formed.
C) Binary fission occurs.
D) The micronuclei disappear.

Question 36

Protozoans in the genus Trypanosoma cause

A) malaria in both humans and birds.
B) amebic dysentery and intestinal ailments.
C) African sleeping sickness and Chagas disease.
D) birth defects if infecting a woman at the appropriate stage of pregnancy.
E) Toxoplasmosis, often contracted from cats.

Question 37

When a protozoan alternates between haploid and diploid generations,as occurs in most plants,it is called

A) zygotic meiosis.
B) gametic meiosis.
C) intermediary meiosis.
D) mitotic meiosis.
E) parthenogenesis.

Question 38

Haploid cells that are unequal in size,such as sperm and egg,are called what?

A) anisogametes
B) syngametes
C) autogametes
D) unigametes
E) isogametes

Question 39

The strange case of organisms that undergo meiosis to produce gametes that fuse to form a zygote internally without leaving the organism is a process called what?

A) syngamy
B) zygotic meiosis
C) gametic meiosis
D) autogamy
E) conjugation

Question 40

To what extent are the cells of a colonial Volvox specialized?rev: 03_26_2014_QC_47370

A) The cells of Volvox are not specialized at all; all are equivalent in function and to be otherwise would make them like those of the metazoa.
B) Somatic cells function in nutrition and locomotion while a few "germ" cells carry out reproduction.
C) Germ cells specialize in locomotion, others in nutrition, and others in reproduction.
D) Volvox is like two organisms living together symbiotically: one set of cells handles nutrition and locomotion and reproduce their type; another type of cell handles sexual reproduction and reproduce their type.
E) A Volvox cell alternates between first being somatic, then being reproductive.

Question 41

The great pyramids of Egypt are made from stone formed from fossil

A) radiolarians.
B) foraminiferans.
C) heliozoans.
D) snails.
E) endoparasitic amoeboids of insects.

Question 42

Which is a member of the apicomplexan group of protists?

A) Amoeba proteus
B) Plasmodium vivax
C) Chlamydomonas
D) Trypanosoma
E) Paramecium

Question 43

Which is an example of a Ciliophoran protozoa?

A) Amoeba
B) Trypanosoma
C) Paramecium
D) Plasmodium
E) Giardia

Question 44

Most ciliophoran protozoa

A) possess flagella.
B) possess a cytostome.
C) are marine.
D) are parasitic.
E) have cyst stages for surviving harsh conditions.

Question 45

How does the mosquito transmit malaria from an ill person to a healthy person?

A) Plasmodium is taken up from one person's blood and squirted back out into the next person.
B) Plasmodium gametocytes are taken up from one person's blood and cross into the saliva duct to be reinjected into the next person.
C) Plasmodium gametocytes are taken up from one person's blood, fuse to form a zygote that becomes a motile ookinete that enters the saliva ducts.
D) Plasmodium gametocytes are taken up from one person's blood, fuse to form a zygote that becomes a motile ookinete, that crosses the stomach wall, forms an oocyst that undergoes sporogony and the sporozoites then migrate to the saliva ducts to be injected into the human host.
E) Plasmodium gametocytes are sucked from one person's blood, form an oocyst that undergoes sporogony and the sporozoites migrate across the stomach lining to the saliva ducts.

Question 46

Giardia lamblia causes

A) malaria in both humans and birds; is carried by mosquitoes.
B) dysentery and intestinal ailments; is found in contaminated water.
C) African sleeping sickness; is carried by the tsetse fly.
D) birth defects; is caused by mosquitos.
E) Toxoplasmosis; contracted from cats.

Question 47

A Paramecium "knows" when it has encountered a noxious substance and backs off to veer away.As a one-celled organism,how does it "know" to do this?

A) The macronucleus has DNA coding that determines this reaction.
B) The micronucleus is dedicated to controlling just such responses.
C) This cell is essentially a small neuron, or nerve cell.
D) This is a rather simple stimulus that changes the electrical potential difference across the cell membrane and depolarization of the membrane results in cilia reversing their direction of beating.
E) None of the choices are correct.

Question 48

The ciliate group of protists would include

A) Amoeba proteus.
B) Plasmodium vivax.
C) Toxoplasma gondii.
D) Entamoeba histolytica.
E) Paramecium caudatum.

Question 49

The chills and fever of malaria are correlated with

A) cycles of schizogony in the liver cells.
B) release of sporozoites from the oocysts.
C) escape of populations of merozoites from red blood cells.
D) the formation of gametocytes.
E) entrance of trophozoites into red blood cells.

Question 50

Mosquitoes that transmit malaria pick up what stage(s)when feeding on the blood of a patient ill with malaria?

A) microgametocytes and macrogametocytes that mature into gametes in the insect host
B) sporozoites from the oocysts
C) merozoites that escape from the red blood cells
D) hemozoin stored in red blood cells
E) trophozoites in red blood cells

Question 51

Chagas disease in the Americas is carried by

A) mosquitoes.
B) contaminated water supplies.
C) contact with cats and cat feces.
D) triatomine "kissing" bugs.
E) sexual contact.

Question 52

Osmoregulation in some protozoa is carried out chiefly by a structure called a/an __________ ___________.

Question 53

Chalky fossils that formed the White Cliffs of Dover were produced by

A) radiolarians.
B) foraminiferans.
C) ciliates.
D) diatoms (as diatomaceous earth).
E) dinoflagellates.

Question 54

Which protozoan group has a complicated parasitic life cycle that nearly always involves the production of infective spores?

A) Apicomplexans
B) Zooflagellates
C) Sarcodines
D) Rhizopods
E) Ciliates

Question 55

The various species of Plasmodium vary in

A) their incubation period.
B) the intensity of their physical symptoms.
C) the number of times they initiate schizogony in liver cells.
D) mortality, or risk of death, to the human host.
E) All of the choices are variables in Plasmodium.

Question 56

Which describes the mode of action of the causative agent of amebic dysentery?

A) It invades the liver and destroys its function, thus altering the digestive system.
B) It ruptures large numbers of red blood cells and the increased fluids are lost across the intestine.
C) It invades the intestinal lining and secretes enzymes that cause loss of fluid; it can also cause abscesses on the liver and other organs.
D) It invades the brain and destroys the control center that regulates intestinal movement of food.
E) All of the choices are correct.

Question 57

After phagocytosis,a food particle is held in a food vacuole also called a/an _____________________.

Question 58

What are the functions of the macronucleus and one or more small micronuclei in Paramecium?

A) The macronucleus undergoes meiosis to produce haploid micronuclei that are exchanged in conjugation; this then produces a micronucleus for general cell housekeeping.
B) The micronucleus undergoes meiosis to produce haploid micronuclei that are exchanged in conjugation; the macronucleus is responsible for the "day-to-day" functions of the cell.
C) Diploid micronuclei control the cell and the haploid macronuclei are exchanged in conjugation for reproduction.
D) A micronucleus is always (1n) for conjugative reproduction, the macronucleus functions for general cell coding, and the two are otherwise unrelated.
E) None of the choices are correct.

Question 59

Which of the following is NOT a "ciliate?"

A) Paramecium
B) Stentor
C) Vorticella
D) Trichodina
E) All of the choices are classified as ciliates.

Question 60

Perhaps half of the U.S.population is infected with this organism that normally resides in tissue cysts containing bradyozoites; embryos of pregnant women are also at risk.

A) Amoeba proteus
B) Plasmodium vivax
C) Toxoplasma gondii
D) Trypanosoma cruzi
E) Entamoeba histolytica

Question 61

The protozoan group that contains only endoparasitic forms is the ____________________.

Question 62

A sporozoan parasite of cats that can cause birth defects in humans is called _________ ________.

Question 63

Small spined extrusomes in ciliate protozoa that are discharged apparently to aid in the capture of prey or to serve as a defensive mechanism are called ______________.

Question 64

Generally,the human body creates antibodies in response to foreign substances that invade our blood or interstitial spaces.How can the malaria organism continue to survive in the human host to cause chills and fevers for years; that is,why do we not build up an immunity in a week or so?

Question 65

Discuss the significance of members of the order Trichomonadida,which possess hydrogenosomes (organelles analogous to mitochondria but which produce molecular hydrogen when oxygen is absent).

Question 66

Some species of slime molds form a large,multinucleate body called a/an _________________.

Question 67

Amebic dysentery is caused by the protozoan species with the scientific name __________ ___________.

Question 68

Explain the scientific reasoning behind the reorganization of the "Protozoa." Why is this important?

Question 69

Foraminiferans are protozoans that form complex,many-chambered tests composed of _____________.

Question 70

Discuss the molecular evidence that has allowed protozoologists to completely revise our concepts of unicellular eukaryote phylogeny.

Question 71

Describe the different classification provided by botanists and zoologists for the same organisms,the algae.Explain why this situation exists.Does it make sense in the light of evolutionary theory?

Question 72

If you grow Euglena in a jar,and mask off all but a slit of light,they soon congregate at the slit.If you completely cover the jar and prevent exposure to light,they convert to heterotrophy.How are these organisms and these traits problematic for systematists?

Question 73

The structure in a Euglena that functions to orient it to light is the _______________________ or eyespot.

Question 74

Gametic nuclei arising by meiosis and forming a zygote within the same organism that produced them is a process called ___________.

Question 75

The Clade (Superphylum)Alveolata contains three phyla: Apicomplexa,Ciliophora,and Dinoflagellata.What are their shared characteristics and why are they placed in this superphylum?

Question 76

What is the most likely habitat in which to find gnathostomulids or jaw worms?

A) under rocks in shallow water
B) inside the intestine of mammals
C) in costal sediment with low oxygen
D) in mountain streams with high oxygen