How can we help?

You can also find more resources in our Help Center.

78 terms

Unit 7

STUDY
PLAY
The usual method of reproduction in bacteria is
a. sexually by conjugation
b. asexually by conjugation
c. sexually by binary fission
d. asexually by binary fission
e. asexually by budding
d. (asexually by binary fission)
If an organism existed that needed both light and pre-formed organic compounds to survive, it would be considered a
a. photoautotroph
b. photoheterotroph
c. chemoautotroph
d. chemoheterotroph
e. none of the above
b. (photoheterotroph)
Which of the following statements concerning viruses is false?
a. They contain nucleic acid.
b. They are smaller than bacteria.
c. They need living cells to reproduce.
d. They do not have cell structures.
e. They metabolize food for energy
e. (They metabolize food for energy) (don't eat, just reproduce themselves using the cell they're in).
Which of the following is not a characteristic of the kingdom Protista?
a. members can be photosynthetic
b. members can be free-living
c. some members move via flagella
d. some members are shaped like rods and termed bacilli
e. some members spend part of their lifecycle inside insects
d. (some members are shaped like rods and termed bacilli) (bacteria, not protists)
Which of the following is not a characteristic of fungus-like protists, such as slime molds?
a. eukaryotic
b. lack cell walls of chitin
c. seemingly multicellular
d. Photosynthetic
e. saprobe
d. (Photosynthetic) (decomposers)
Which statement is true of the organisms in Kingdom Fungi?
a. Most are unicellular.
b. All have vascular tissue.
c. Most are decomposers.
d. Most are highly poisonous.
e. All are autotrophic
c. (Most are decomposers)
Which of the following is a club fungus?
a. mushroom
b. yeast
c. bread mold
d. lichen
e. mycorrhiza
a. (mushroom)
Which of these is autotrophic?
a. an amoeba
b. an algae
c. a ciliate
d. a fungus
e. more than one of the above
b. (an algae) (plant-like protists that can do photosynthis)
Compare and contrast the lytic and lysogenic cycles of viral infection.
(Lytic: virus enters cell, takes over the cell machinery to make bunches of copies of itself (replicates), bunch of newly formed viruses in host cell, to get out host cell burst through cell membrane (burst), new virus particles infect other cells)

(Lyosogenic: virus enters host cell, inserts its DNA into host cell DNA, every time host DNA replicates it replicates virus DNA, doesn't kill host cell) (slow reproduction of virus)


Define lytic infection, and summarize the steps of this type of infection.
In a lytic infection, a virus enters a cell, makes copies of itself, and causes the cell to burst.
1. Bacteriophage injects DNA into bacterium.
2. Bacteriophage DNA forms a circle.
3. Bacteriophage takes over bacterium's metabolism, causing synthesis of new bacteriophage proteins and nucleic acids.
4. Bacteriophage proteins and nucleic acids assemble into complete bacteriophage particles.
5. Bacteriophage enzyme lyses the bacterium's cell wall, releasing new bacteriophage particles that can attack other cells.


Define lysogenic infection.
In a lysogenic infection, a virus integrates its DNA into the DNA from the host cell, and the viral genetic information replicates along with the host cell's DNA. Unlike lytic viruses, lysogenic viruses do not lyse the host right away. Instead, a lysogenic virus remains inactive for a period of time.

1. Bacteriophage injects DNA into bacterium.
2. Bacteriophage DNA forms a circle.
3. Bacteriophage DNA inserts itself into bacterial chromosome
4. Bacteriophage DNA (prophage: the viral DNA that is embedded in the host's DNA) may replicate with bacterium for many generations
5. Bacteriophage DNA (prophage) can exit the bacterial chromosome. Bacteriophage enters lytic cycle.
a. Bacteriophage takes over bacterium's metabolism, causing synthesis of new bacteriophage proteins and nucleic acids.
b. Bacteriophage proteins and nucleic acids assemble into complete bacteriophage particles.
c. Bacteriophage enzyme lyses the bacterium's cell wall, releasing new bacteriophage particles that can attack other cells.
Archaea differ from Bacteria in that the cell walls of Archaea lack PEPTIDOGYLCAN.
True
Many ARCHAEBACTERIA live in extreme environments, such as in Utah's Great Salt Lake
True
The spiral-shaped organism labeled B in Figure 19-2 is an example of a SPIRILLUM.
True
Bacteria can cause disease by releasing TOXINS into the body
True
An ANTIBIOTIC is a preparation of weakened or killed virus or viral proteins
False, vaccine
A DISINFECTANT is a chemical solution that kills bacteria
True
Protists are a diverse group of mainly MULTICELLULAR eukaryotes.
False, unicellular
Ciliates use FLAGELLA for feeding and movement
False, cilia
EUGLENAS have cell walls composed of silica and shaped like the two sides of a pillbox
False, diotoms
Fungus-like protists are AUTOTROPHS
False, heterotrophs
Slime molds and water molds are important DECOMPOSERS
True
Fungi are PROKARYOTICheterotrophs
False, eukaryotic
Fungi ABSORB their food
True
In some fungi, the NUCLEI are divided by cross walls
False, hyphae
Fungal cell walls are composed of CELLULOSE
False, citin
Fungi recycle NUTRIENTS in all ecosystems
True
Mycorrhizae are beneficial associations of fungi and ANIMALS
False, plants
Single-celled macroorganism that lacks a nucleus (471)
Prokaryote
Rod-shaped prokaryote (473)
Bacillus
Spherical prokaryote (473)
Coccus
Spiral or corkscrew-shaped prokaryote (473)
Spirillum
Prokaryote that is phtosynthetic but also needs organic compounds for nutrition (474)
Photoheterotroph
Heterotrophic prokaryotes that must take in organic molecules for both energy and a supply of carbon (most animals, including humans) (473)
Chemoheterotroph
Prokaryote that obtains energy directly from inorganic molecules using chemical reactions (474)
Chemoautotroph
Prokaryote that carries out photosynthesis in a manner similar to that of plants (474)
Photoautotroph
Like all organisms, bacteria need a constant supply of energy. This energy is released by the process of cellular respiration or fermentation or both. Organisms that require a constant supply of oxygen in order to live are called obligate aerobes.
(Obligate means that organisms are obligated, or required, by their life processes to live only in a particular way)
obligate aerobe
Some bacteria, however, do not require oxygen and, in fact, maybe killed by it! These bacteria are called obligate anaerobes, and they must live in the absence of oxygen.
obligate anaerobe
A third group of bacteria can survive with or without oxygen and are known as facultative anaerobes.
(Facultative means that the organisms are able to function in different ways, depending on their environment)
Facultative anaerobes do not require oxygen, but neither are they killed by its presence. Their ability to switch between the processes of cellular respiration and fermentation means that facultative anaerobes are able to live just about anywhere
facultative anerobe
Type of asexual reproduction in which a prokaryote replicates its DNA, and divides in half, producing two identical daughter cells (476)
binary fission
Form of sexual rperoduction in which paramecia and some prokaryotes exchange genetic information (476)
Conjugation
Type of spore formed when a bacterium produces a thick internal wall that encloses its DNA and a protion of its cytoplasm (476)
Endospore
Process of converting nitrogen gas into ammonia (478)
nitrogen fixation
Outer protein coat of a virus (483)
Capsid
Virus that infects bacteria (484)
Bacteriophage
Process in which a virus enters a cell, makes a copy of itself, and causes the cell to burst (485)
Lytic infection
Process by which a virus embeds its DNA into the DNA of the host cell and is replicated along with the host cell's DNA (485)
lysogenic infection
Prophage
The viral DNA that is embedded in in the host's DNA
Particles of nucleic acid, protein, and in some cases, lipids.
Can only reproduce by infecting living cells.
Typically composed of a core of DNA or RNA surrounded by a protein coat.
Parasites (dependent entirely upon another living organism for its existence)
Borderline of living and nonliving things
Virus
Virus that contains RNA as its genetic information (487)
Backwards ("retro" means backwards); genetic information is copied from RNA to DNA
Causes cancers, AIDS
Retrovirus
Disease-causing agent, such as a bacterium or fungus (479)
Pathogen
Injection of a weakened or mild form of a pathogen to produce immunity (1040)
Vaccine
Compound that blocks the growth and reproduction of bacteria (480)
Antibiotic
Single-stranded RNA molecules that have no surrounding capsids (490)
Cause disease in plants
Enter infected cell and direct the synthesis of new viroids
Viroid
Infectious particle made up of protein rather than RNA or DNA (487)
Cause disease in animals
"Protein infectious particles"
Form protein clumps that induce normal protein molecules to become prions
Prion
Heterotrophs
Zooflagellates swim with flagella, sarcodines move by extensions of their cytoplasm (pseudopods), ciliates move by means of cilia, and sporozoans do not move on their own at all (parasitic) (499)
Animallike protists
Projection of cytoplasm, or false foot, used by some protists (sacodines) for feeding or movement (498)
Pseudopod
Type of locomotion used by amoebas (sarcodines)
The cytoplasm of the cell streams into the pseudopod, and the rest of the cell follows (498)
amoeboid movement
Small cavity in the cytoplasm of protists that temporarily stores food (498)
food vacuole
Small, bottle-shaped structures used for defence by paramecia (ciliates) (499)
Trichocyst
The larger of the ciliate's two nuclei, contains multiple copies of most of the genes that the cell needs in its day-to-day existance (499)
Macronucleus
The smaller of a ciliare's two nuclei; contains a "reserve copy" of all the cell's genes (499)
Micronucleus
Cavity in the cytoplasm of some protsists (paramecium, ciliates) that collects water and discharges it from the cell; homeostasis (500)
contractile vacuole
Chlorophyll and accesory pigments allow algae to harvest and use the energy from sunlight
Four phyla: euglenophytes (two flagella but no cell wall), chrysophytes (golden plants), diatoms (cell walls rich in silicon), and dinoflagellates (half photosynthetic half heterotrophs) (508)
Plantlike protists
Cluster of reddish pigment near the gullet end of the cell that helps the organism find sunlight to power photosynthesis (euglenophytes) (506)
Eyespot
Population of algae (plantlike protists) and other small, photosynthetic organisms found near the surface of the ocean and forming part of plankton; perform about half of the photosynthesis that occur on Earth (508)
Phytoplankton
Haploid reproductive cell
When male and female gametes fuse, they produce a diploid zygote cell, which then grows nto a large, diploid multicellular Ulva. The diploid Ulva undergoes meiosis to produce haploid reproductive cells called ___. Each of these is able to grow into a new individual without fusing with another cell. (514)
Spore
Like fungi, the funuslike protists are heterotrophs that absorb nutrients from dead or decaying organic matter. But unlike most true fungi, funguslike protists have centrioles. They also lack the chitin cell walls of true fungi (cellular slime molds, acellular slime molds, and water molds) (516)
Funguslike protists
Funguslike protists that play key roles in recyclilng organic material (516)
Slime molds
Slender reproductive structure that produces spores (cellular slime molds, funguslike protists); reproductive structure growing from the mycelium in the soil beneath it (mushroom is fruiting body of fungus) (528)
fruiting body
Eukaryotic heterotrophs that have cell walls, all muticellular (except yeast) (absorb nutrients from decaying matter in soil, parasites that absorb nutrients from host); four main groups: common molds, sac (includes yeast), club (spore-bearing reproductive structure basidium), and imperfect; maintain equilibrium in ecosystems by recycling nutrients by breaking down the bodies and wastes of other organisms
Fungi
Complex carbohydrate that makes up the cell wall of fungi (527)
Chitin
Tiny filament that makes up a multicellular fungus or a water mold (518, 527)
Hyphae
Many hyphae tangled together into a thick mass; comprises the bodies of multiceullar fungi; absorb food(528)
Mycelium
Structures where spores are produced in some fungi; found at tip o specialized hyphae called sporangiophores (528)
Sporangia
Process of attaching a bud to a plant to produce a new branch; asexual reproduction of yeasts (fungi) (533, 623)
Budding
Organism that obtains food from decaying organic matter (many fungi) (537)
Saprobe
...
Saprophyte
Symbiotic association between a fungus and a photosynthetic organism (540)
Lichen
Symbiotic association of plant roots and fungi (541)
Mycorrhiza