Bio chapter 28
How is an eukaryote classified as a protist?
A eukaryote is classified as a protist when it cannot be classified in any other eukaryotic group.
What type of prokaryote might have formed endosymbiotic relationships with other larger bacteria, eventually evolving into a chloroplast?
A photosynthetic bacterium
The genome of a mitochondrion is typically composed of which of the following?
A single, circular, closed molecule of DNA, similar to that in bacteria
Which of the following is a branch of the supergroup SAR that is distinguished from other protists by the presence of flattened vesicles stacked in a continuous layer beneath their plasma membrane?
Alveolates
In fungi and some protists, the does what not dissolve during mitosis.
Blank 1: nuclear Blank 2: membrane or envelope
Protists can exhibit both _______ and ___________ reproduction.
Blank 1: sexual Blank 2: asexual
Because of its simple developmental system, this cellular slime mold is used as a model organism in studies of cell differentiation.
Dictyostelium discoideum
Select all types of cell surfaces found in protists.
Glassy silica shell Extracellular matrix Plasma membrane
Select features of protists in the supergroup Excavata.
Many possess a feeding groove. They move using flagella.
Which of the following describes the flagella of protists in the Excavata?
Parabasalids and diplomonads have multiple flagella while euglenozoans have unique flagella.
Which of the following are nutritional strategies found in protists?
Phagotrophs Phototrophs Mixotrophs
Which of the following best describes reproduction among protists?
Protists typically reproduce asexually, but some undergo sexual reproduction regularly and others reproduce sexually only at times of stress.
Cercozoa, Foraminifera, and Radiolaria are the three groups that comprise the
Rhizaria
The Alveolata, Rhizaria, and Stramenopila make up the eukaryotic supergroup called ______
SAR
select all nutritional strategies of oomycetes.
Saprophytic Parasitic
Radiolarians secrete glassy exoskeletons made of which of the following?
Silica
Select all of the subgroups within the eukaryotic supergroup called SAR.
Stramenopiles Alveolates Rhizaria
In most eukaryotes (with the exception of fungi and some protist groups), the separation of chromosomes during mitosis occurs in what part of the cell?
The cytoplasm
Choose all features of Chlamydomonas.
They are members of the green algae. They have two flagella at their anterior end. They are unicellular microscopic organisms.
What are two general features of all apicomplexans?
They are spore-forming protists. They are parasites of animals.
What is the function of the undulating membranes in parabasalids?
They are used for locomotion.
Kinetoplastids are a group of Euglenozoa that characteristically have
a single mitochondrion
Mitochondria and chloroplasts contain their own DNA which is very similar in size and character to the DNA of
bacteria or prokaryotes
The evolution of multicellularity was advantageous because it allowed ______.
cells to become specialized
The evolution of multicellularity was advantageous because it allowed ________
cells to become specialized
Which of the following are not found in red algae?
centrioles and flagella
Pseudopods are flowing projections of ________ that are used by many protists for locomotion.
cytoplasm
Cellular slime molds are important model organisms used in the study of cell
differentiation.
Protists that possess two flagella, plates made of a cellulose-like material, and may be bioluminescent or produce toxins are
dinoflagellates
The nucleus and the ER of eukaryotes are thought to have evolved ______.
from infoldings of the plasma membrane
The _______ life cycle of the brown algae is marked by alternation of generations between multicellular sporophyte and gametophyte generations.
haplodiplontic
Members of the phylum Foraminifera are _______
heterotrophic marine organisms
The earliest eukaryotic cells likely evolved through the transfer of genes across species boundaries, a process called_________________ gene transfer.
horizontal
Which of the following were the first eukaryotes?
protists
Select features of protists in the supergroup Excavata. Multiple select question.
They move using flagella. Many possess a feeding groove.
Which of the following are characteristic of Foraminifera?
They resemble tiny snails. They are heterotrophic. They are marine.
Among euglenozoa, the kinetoplastids are a second major group that are unique because they have ________
a single mitochondrion in each cell
Radiolarians secrete glassy exoskeletons made of silica. That exoskeleton ______
give them distinct symmetrical shapes
Spore-forming parasites of animals that are characterized by a structure at one end of the cell that facilitates the invasion of a host are members of what group?
Apicomplexans
The undulating membrane of parabasalids is used in which of the following?
locomotion
Amoebas are surrounded only by their plasma_______
membrane
During conjugation in ciliates, each of the two partners receives a pair of haploid ________ from the other partner.
micronuclei
Amoebas use their pseudopods to
move and engulf food
Diplomonads are unique because they possess two what per cell.
nuclei or haploid nuclei
Autotrophic protists include those that are_____
photosynthetic chemoautotrophic
Some slime molds produce a non-walled, multinucleate mass of cytoplasm called a(n)
plasmodium
Euglenozoans exhibit extreme flexibility; they change shape while swimming thanks to strips of ________ encircling their cells rather than a cell wall.
proteins
Eukaryotic organisms that cannot be classified in the plant, animal, or fungal kingdoms are
protists
All oomycetes are either parasitic or
saprophytic (organisms that live by feeding on dead organic matter)
Although there are some parasitic species, most amoebae are free-living and are found in Blank and blank environments
soil freshwater
The alternation of generations in brown algae involves the production of multicellular what (diploid) and multicellular what (haploid) generations.
sporophyte gametophyte
Excavata, SAR, Archaeplastida, Amoebozoa, and Ophisthokonta are the names of the five protist
supergroups
Diatoms are photosynthetic, _______ organisms with unique double shells made of silica.
unicellular
Order the steps of conjugation in ciliates, starting at the top.
1. two cells of different mating types form a cytoplasmic bridge 2. the two partners exchange a pair of haploid micronuclei 3. each partner, new haploid micronucleus fuses with the old haploid micronucleus giving rise to a new diploid micronucleus 4. macronucleus disintegrates 5. the new diploid micronucleus divides by mitosis and generated two identical diploid micronuclei 6. one of the two diploid micronuclei undergoes many rounds of replication and becomes a macronucleus
Which of the following is the best definition of endosymbiotic bacteria?
Bacteria that live within other cells and perform specific functions for their host cells
What group of protists primarily dwell in the soil, use either flagella or pseudopods for movement, and sometimes have shells made of silica?
Cercozoans
The archaeplastid group that shares a common ancestor with the land plants is
Charophytes
Which of the following statements about dinoflagellates are true?
They have alveoli. Their chloroplasts are similar to those of diatoms or brown algae. They are protected by plates composed of a cellulose-like material.
Infoldings of the prokaryotic plasma membrane are thought to have given rise to the eukaryotic endomembrane system that includes which of the following?
Endoplasmic reticulum (ER), and nuclear envelope
Select all evolutionary mechanisms that were important in the early evolution of eukaryotes.
Engulfing other cells Horizontal gene transfer
What group of protists is characterized by their lack of a cell wall, having instead flexible protein strips that give them flexibility and allow them to change shape while swimming?
Euglenozoans
Which of the following are currently recognized supergroups of protists?
Excavata Amoebozoa Ophisthokonta SAR
Select all structures used by protists for locomotion.
Flagella Cilia Pseudopods
Which of the following is an advantage of multicellularity?
It fostered the specialization of cells.
Select all features of the feeding phase of a plasmodial slime mold.
It has multiple nuclei. It does not have cell walls.
Which of the following statements about amoeba is correct?
Most amoeba are free-living and can be found in the soil as well as freshwater.
Choose all of the following structures/mechanisms that can be used by cercozoans for motility.
Pseudopods Flagella
Select all features of diplomonads.
They are unicellular. They have two nuclei. They lack functional mitochondria.
In the SAR clade that includes the dinoflagellates, apicomplexans, and ciliates, a common trait is the presence of flattened vesicles below the plasma membrane called what
alveoli
The Archaeplastida group that shares a common ancestor with the land plants is ________
charophytes
Scientists hypothesize that photosynthetic bacteria were engulfed by other, larger cells and eventually evolved to become the organelles we now call
chloroplasts
Evidence suggests that members of the Opisthokonta, called choanoflagellates Blank, Correct Unavailable, are similar to the most likely common ancestor of all animals.
choanoflagellates
In ciliates, sexual reproduction involves the process of what, during which two individual cells are attached for up to several hours.
conjugation
Photosynthetic stramenopile protists in the phylum Chrysophyta with double silicate shells are commonly called
diatoms
Protists that possess two flagella, plates made of a cellulose-like material, and may be bioluminescent or produce toxins are _____
dinoflagellates
Bacteria that live within other cells and perform specific functions for their host cells are called Blank______.
endosymbiotic bacteria
Chlamydomonas cells are small, green, and rounded, and have two ______ at their anterior end.
flagella