Bio final (ch. 27- 30)
Entamoeba histolytica, a parasite that is the causative agent of Amoebic Dysentery, crawls through the small intestine of its victims via pseudopod formation. Based on this information, Entamoeba histolytica is a member of the clade
Amoebozoa
Among the protists below, which typically moves with one "tinsel" flagella and one "smooth" flagella?
Diatoms
Protists like ________________ represent an intermediate stage in eukaryotic evolution when cells each had two haploid nuclei but fusion to become a true diploid organism had not occurred.
Giardia
SELECT ALL THAT APPLY Which of the following cellular structures are shared by bacteria, archaea, and eukaryotes?
Plasma membrane
Which of the following groups of prokaryotes in the figure above contains the bacteria Helicobacter pylori, responsible for the human ulcers, and E. coli, beneficial intestinal bacteria in humans?
Proteobacteria
Organisms that share the most DNA homology to mitochondria and chloroplasts, respectively, are:
Proteobacteria, cyanoacteria
Clostridium tetani
Tetanus ("Lockjaw")
Bacillus anthraxis
anthrax
Molecular data in support of endosymbiosis indicates that chloroplasts are highly similar to __________ that may have been engulfed by a heterotrophic eukaryote over a billion year ago.
dinoflagellates
Which organisms are capable of producing a "red tide", secreting a nerve agent toxic to humans?
dinoflagellates
In paramecium and stentor, the surface of the cell is covered with thousands of short, hairlike _____:
cilia
Some bacteria avoid a host's immune system by means of:
cloaking the cell with a watery capsule
Even though bacteria lack membrane-bound organelles, such as chloroplasts and mitochondria, they can still perform the functions of these organelles by localizing certain metabolic enzymes on:
infoldings of the plasma membrane.
The parasitic protist that causes malaria, Plasmodium, must spend part of its life cycle in a nonhuman host. What organism(s) serve(s) as the vector for this life cycle?
mosquitoes
Pseudopods are used by the members of clade Amoebozoa for ingesting food as well as for
movement.
Extrachromosomal circles of DNA in bacteria called ______ often carry genes involved in _______:
plasmids, antibiotic resistance.
Many Gram (+) Eubacteria like Clostridium botulinum and Bacillus anthraxis have the ability to survive harsh environmental conditions by protecting their DNA in a dormant structure called a(n)
endospore
Neisseria gonorrhea
gonorrehea
Helicobacter pylori
stomach ulcers
The first indication that Archaea were different from the Eubacteria came from
the absence of peptidoglycans in the cell walls of the Archaea.
Evidence that Chara is the direct ancestor of all land plants includes
the mechanism of cell wall synthesis in Chara and all land plants the presence of homologous chloroplasts (chlorophylls a and b, as well as accessory pigments) in Chara and all land plants *A and C only.
Which parasitic protist has 2 haploid nuclei, 2 pairs of flagella, remnants of mitochondrial genes (but no intact mitochondria) and lives and reproduces in the small intestines of mammals?
. Giaridia
What is the function of the structures labeled B?
All answers except B
Which example below is a characteristic shared by all excavates (diplomonads and parabasalids):
Both lack, or have highly reduced, mitochondria.
Clostridium botulinum
Botulism (food poisoning)
The structure in the accompanying figure labeled C (outermost layer) is ___, and the structure indicated by the letter I is _____:
C - the capsule, I - the flagella
What type of protists have formed massive deposits of chalk, as seen in the White Cliffs of Dover?
Cercozoans (Forams)
Which of the following groups of prokaryotes might be found in the Great Salt Lake, the Red Sea, the Dead Sea, but NOT necessarily in the ocean?
Extreme Halophiles
The ____ Archaebacteria are typically found in extremely hot environments, whereas the _______ Archaebacteria are typically found in swampy environments lacking oxygen.
Extreme thermophile, methanogenic
The mitochondria of eukaryotic cells most likely arose as a result of endosymbiosis between a eukaryotic cell and a
Gram (-) bacterium like Rickettsia
Which of the following groups of prokaryotes contains the genus Clostridium, responsible for the human diseases tetanus and botulism?
Gram Positive Eubacteria
What makes rRNA (or another sequence) a good 'evolutionary chronometer'?
It is universally distributed across group chosen - all organisms have rRNA. It is functionaly similar between organisms - rRNAs all participate in protein synthesis. Its sequence changes slowly - good for looking across long periods of time The rRNA sequences can be aligned, or matched up, between 2 organisms. * All of the above
Trypanosomes are eukaryotes that are currently classified in the SuperClade
Superclade I: Excavata
Which of the following is true about Radiolarans?
They capture prey through the use of thread-like pseudopods
Most bacterial cells keep from bursting in a hypotonic environment by
a rigid cell wall.
.Once they appeared on Earth, ___ forever changed the atmosphere on earth by the production of large quantities of oxygen gas
cyanobacteria
A commercially important unicellular protist whose silica shells are used in filters, polishes, toothpaste and various industrial processes are the:
diatoms
.Prokaryotes found inhabiting the Great Salt Lake would be the _____
extreme halophiles
Evidence for the Endosymbiotic Theory (Margulis, 1967) includes
similarity between bacterial size and the size of mitochondria and chloroplasts the presence of a single circular chromosome in bacteria, mitochondria, and chloroplasts reproduction by binary fission in bacteria, mitochondria, and chloroplasts 70S ribosomes in bacteria, mitochondria, and chloroplasts *All of the above provides evidence for the Endosymbiotic Theory.
The most significant difference between the Archaea and the Eubacteria is:
the small subunit (16 S) rRNA sequence
Euglena and dinoflagellates show Secondary Endosymbiosis in that
they have three lipid bilayers around their chloroplasts