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