Biology chapter 16

prokaryotes are useful for cleaning up contaminants in the environment because

they have great nutritional diversity, are quickly adaptable, and can form biofilms

Bacterial _____ are at work in the slimy feel of an underwater rock, ear infections, and dental plaque. a) reproductive behaviors b) cell walls c) endospores d) biofilms

d

protist habitat

diverse; most protists are aquatic and other inhabit the bodies of various host organisms

cell walls of archaea

do not contain peptidoglycan but can also be gram positive or negative

flagella

enables bacteria and archaea to move; lacks microtubules;

fimbriae

enables some prokaryotes to stick to a surface or to one another;

stramenopila

examples: diatoms and brown algae

rhizaria

foraminiferans, radiolarians

gametophyte

produces gametes;

By far the most abundant and widespread organisms on Earth are the _____. eukaryotes prokaryotes protozoans algae

prokaryotes

microbiota

the community of micro-organisms that live in and on our bodies

endosymbiont theory

explains the origin of mitochondria and chloroplasts; according to this theory, oxygen-using prokaryotes established residence within other larger prokaryotes; these endosymbionts evolved into mitochondria giving rise to heterotrophic eukaryotes;

alternations of generations

a multicellular diploid (2n) form (sporophytes) alternates with a multicellular haploid form (gametophyte);

prokaryotes vs eukaryotes

eukaryotic cells have membrane enclosed nucleus and many other membrane enclosed organelles; prokaryotic cells lack these structures; prokaryotic cells have smaller size than eukaryotic cells;

multicellular organisms have evolved from three different lineages

stramenopiles, unikonts and archaeplastids

Prokaryotes found inhabiting the Great Salt Lake would be _____. a) methanogens b) extreme thermophiles c) extreme halophiles d) cyanobacteria

c

Prokaryotes that use light for their energy source and CO2 for their carbon source are called _____. a) chemoheterotrophs b) chemoautotrophs c) photoautotrophs d) photoheterotrophs

c

You are examining material from an unknown life-form extracted from a sample taken in the deep sea. Which of the following clues would convince you the sample came from a bacterial cell? a) histones associated with DNA b) membrane-enclosed organelles c) peptidoglycan in the cell wall material d) some genes lacking introns

c

symbiosis

close association between organisms of two or more species

archaea genes

some are similar to bacteria, some to eukarya and some to themselves; archaea are one of the most abundant cell types in earth's largest habitat

peptidoglycan

a polymer of sugars cross linked by short polypeptides

capsule

a sticky layer of polysaccharide or protein; enables prokaryotes to cling to a surface or other individuals in colony; can also shield pathogenic prokaryotes from attacks by host's immune system

chlorination

most common method of ensuring that drinking water does not contain any harmful micro organisms

photoheterotrophs

obtain energy from sunlight but get their carbon atoms from organic sources; found in only few types of bacteria called purple nonsulfur bacteria; many found in aquatic sediments; cannot convert CO2 to sugars

dinoflagellates

(diverse group that includes unicellular autotrophs, heterotrophs, and mixotrophs) are common components of marine and freshwater plankton (communities of micro organisms that live near the water's surface); blooms of autotrophic dinoflagellates sometimes cause warm coastal waters to turn pinkish orange, a phenomenon known as red tide; toxins produced by red tide dinoflagellates have killed large number of fish

A sign on the beach states, "Beach Closed. Red Tide." The organisms interfering with your use of this beach also might poison you through a meal of clams or mussels. They are _____. A) dinoflagellates B) amoebas C) ciliates D) diatoms

A

Among the three domains of life, bacteria are unique in having _____. A) peptidoglycan cell walls B) histones associated with DNA C) mitochondria D) introns (noncoding sequences within genes)

A

Bacteria that live around deep-sea hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon dioxide obtained from the seawater. These bacteria are _____. A. chemoautotrophs B. photoautotrophs C. chemoheterotrophs D. photoheterotrophs

A

Koch's postulates are the steps used to prove _____. A. that a particular microorganism is the cause of a particular disease B. whether an organism is dead or alive C. that a particular antibiotic is effective against a particular bacterial infection D. that a particular microorganism is related to other similar organisms

A

The chemoheterotroph Proteus vulgaris is a rod-shaped bacterium classified with _____. A. proteobacteria B. chlamydias C. spirochetes D. gram-positive bacteria E. cyanobacteria

A

Which of these groups includes the malaria parasite? A) apicomplexans, such as Plasmodium B) ciliates such as Paramecium C) euglenazoans, such as Euglena D) water molds

A

Bacteria that live around deep-sea hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon dioxide obtained from the seawater. These bacteria are _____. A) chemoautotrophs B) photoheterotrophs C) chemoheterotrophs D) photoautotrophs

A Chemoautotrophs use inorganic molecules for energy, and carbon dioxide for carbon.

The photoautotrophic prokaryotes that generate oxygen as a by-product are the _____. A) cyanobacteria B) archaea C) spirochetes D) proteobacteria

A These bacteria pioneered plantlike photosynthesis and were eventually incorporated into protists and plants as chloroplasts.

The evolutionary incorporation of algae into other protist groups, leading eventually to formation of photosynthetic organelles, is termed _____. A) secondary endosymbiosis B) algivory C) primary endosymbiosis D) cyanobacterial endosymbiosis

A Secondary endosymbiosis involved protists taking on algae (other protists) as endosymbionts. primary endosymbiosis involved prokaryote endosymbionts

Around hydrothermal vents at depths of more than 2,500 m, scientists have found colonies of giant tube-dwelling worms. The worms contain symbiotic prokaryotes that are able to use hydrogen sulfide as an energy source for the synthesis of organic matter from carbon dioxide. The bacteria are _____. A. photoheterotrophic B. chemoautotrophic C. chemoheterotrophic D. photoautotrophic

B

Evidence available indicates that the three major multicellular kingdoms (plants, animals, and fungi) arose _____. A. from a single common ancestor that resembled a water mold B. from two different lineages of protists (one for plants, one for animals and fungi) C. from a single common ancestor similar to a colonial choanoflagellate D. from colonial aggregates of several different protist groups that were eventually integrated into a multicellular body

B

Organisms that can cause nongonococcal urethritis are classified with _____. A. proteobacteria B. chlamydias C. spirochetes D. gram-positive bacteria E. cyanobacteria

B

The prokaryotes most likely to be found living in extreme environments such as salt ponds or hot springs are _____. A) photoautotrophs B) archaea C) bacteria D) gram-positive bacilli

B

Amoebas move and feed by using _____. A. flagella B. fimbriae C. pseudopods D. cilia

C

Several groups of protists have variable modes of nutrition: Some species are photoautotrophs, whereas close relatives are heterotrophs. Such diversity even exists within a single species in some cases. Evidence suggests that this pattern is a result of the __________. A) independent acquisition of cyanobacterial endosymbionts by many different protist groups, with subsequent evolution to produce chloroplasts B) loss of chloroplasts from multiple groups of protists, and sometimes even from individuals within groups C) independent acquisition of green and red algae as endosymbionts by many protist groups, with subsequent evolution producing photosynthetic organelles D) independent evolution of photosynthesis in multiple protist lineages through mutations to their pigment-producing genes

C

Spiral-shaped bacteria are likely to be placed with _____. A. proteobacteria B. chlamydias C. spirochetes D. gram-positive bacteria E. cyanobacteria

C

The bacterium Bacillus thuringiensis can withstand heat, dryness, and toxic chemicals that would kill most other bacteria. This indicates that it is probably able to form _____. A) pseudopodia B) endotoxins C) endospores D) fimbriae

C

Which of the following constitutes the use of a biological weapon? A) Many soldiers in the American Civil War died from dysentery due to lack of sanitation and water treatment. B) In World War I, many soldiers died from influenza, which spread rapidly through their crowded barracks. C) Members of a commune in Oregon contaminated a salad bar at a local restaurant with Salmonella bacteria to try to manipulate a local election by making people too sick to vote. D) A terrorist group releases synthetic nerve gas into a subway system.

C

__________ has specially modified mitochondria that generate some energy anaerobically. Moreover, it causes an increasingly common and problematic sexually transmitted disease. A) dinoflagellates B) Euglena C) Trichomonas vaginalis D) Paramecium

C

Which of the following are heterotrophic protists? A. chlamydias B. brown algae C. amoebas D. diatoms

C Amoebas are protozoans that are heterotrophic protists.

Choanoflagellates are single-celled protists with a collar-like structure that resemble cells called choanocytes in sponges. This resemblance most likely reflects _____. A. common ancestry; choanoflagellates are probably derived from choanocytes and have become independent life-forms through simplification of a sponge animal B. chance; protists and animals are unrelated C. convergent evolution; protists and animals are unrelated D. common ancestry; choanoflagellates are probably a sister group closely related to the animals

D

Disease-causing prokaryotes, called _____, are _____. A) proteobacteria ... of minor significance, causing only about 10% of human diseases B) methanogens ... important, but of minor significance compared to the vital roles of pathogens in sustaining life C) pathogens ... the direct cause of nearly all human diseases; they provide few benefits to other forms of life D) pathogens ... important, but of minor significance compared to the vital roles of prokaryotes in sustaining life

D

E. coli bacteria, which live in human intestines, are shaped like tiny, straight sausages. They are _____. A) spirilla B) cocci C) spirochetes D) bacilli

D

In general, how do algae and protozoans differ? A. Algae are free-living, and protozoans are parasitic. B. Protozoans can move, and algae cannot. C. Protozoans are autotrophic, and algae are heterotrophic. D. Algae are photosynthetic, and protozoans are usually heterotrophic.

D

Streptococcus aureus is classified with _____. A. proteobacteria B. chlamydias C. spirochetes D. gram-positive bacteria E. cyanobacteria

D

The protists are _____. A) an informal category of eukaryotes that are not plants, animals, or fungi; they include archaea and chlamydias B) a group of plants (algae) and animals (protozoans) that have become unicellular through evolutionary simplification C) a group of unicellular eukaryotes D) an informal category of eukaryotes that are not plants, animals, or fungi; they include algae and protozoans

D

The prokaryotic cells that built stromatolites are classified as _____. A. proteobacteria B. chlamydias C. spirochetes D. gram-positive bacteria E. cyanobacteria

E

A prokaryote collected from a hot spring in Yellowstone National Park provided scientists with a key protein for the polymerase chain reaction (PCR). PCR has enabled modern biotechnology breakthroughs such as DNA fingerprinting from crime scene samples. The special property of the prokaryote protein is that it functions at very high temperatures. What kind of organism was the prokaryote? a) an extreme thermophile b) an extreme halophile c) an endospore-forming bacterium d) Escherichia coli

a

A student is looking at a protozoan under the microscope. "I know it's supposed to be a ciliate or an amoeba, but how am I supposed to know which it is?" she complains to her lab partner. "Easy," her partner says. "Just _____." a) watch how it moves b) look at its chloroplasts c) find out what it eats d) see whether it has a nucleus

a

Ancient cyanobacteria, found in fossil stromatolites, were very important in the history of life because they _____. a) produced the oxygen gas in the atmosphere b) were the first multicellular organisms c) were probably the first living things to exist on Earth d) are the oldest known archaea

a

Consider the following kinds of organisms: apicomplexans, dinoflagellates, and ciliates. All of these organisms belong to which group? a) alveolates b) animal-like protists c) prokaryotes d) algae

a

Peptic ulcers are caused by _____. a) infection by the bacterium H. pylori b) a viral infection c) stress d) eating spicy foods

a

Protists are a diverse group of organisms that includes _____. a) algae and protozoans b) only algae c) plants d) only protozoans

a

Which of these groups is characterized by cells that have more than one nucleus? a) ciliates b) diatoms c) dinoflagellates d) apicomplexans

a

In the developed world, bacterial disease problems have been reduced primarily through _____. a) improved immune responses b) better sanitation, including safe water treatment and sewage systems c) antibiotic drug use d) antibiotic resistance

b

Methanogens, extreme halophiles, and extreme thermophiles are examples of _____. a) heterotrophic bacteria b) archaea c) bacteria d) protozoa

b

Starting about 500 million years ago, large life-forms began to _____. a) band together to form multicellular bodies b) colonize land c) release oxygen into the atmosphere d) develop eukaryotic cells

b

The cells of cellular slime molds bear a resemblance to _____ cells. a) ciliate b) amoeba c) flagellated d) diatom

b

Which of the following is named for the hairlike structures that they use to move and feed? a) euglenazoans b) ciliates c) parabasilids d) amoebas

b

Which of the following might typically be caused by bacteria? a) AIDS b) food poisoning c) common cold d) malaria

b

Which option provides evidence for the role of endosymbiosis in the origin of eukaryotes? a) Mitochondria and chloroplasts contain large, complex, and diverse types of ribosomes. b) Chloroplasts and mitochondria have their own DNA and reproduce by binary fission. c) Mitochondria reproduce sexually. d) Mitochondria and chloroplasts contain multiple chromosomes that are extensively condensed through the presence of histones.

b

Cyanobacteria are _____. a) pathogenic b) chemoheterotrophs c) photoautotrophs d) archaea

c

The protist pictured below has a unique glassy cell wall that forms a two-part capsule around each cell. What is it? a) a ciliate b) an amoeba c) a diatom d) a dinoflagellate

c

Which of the following are heterotrophic protists? a) brown algae b) diatoms c) amoebas d) chlamydias

c

Which of these groups includes the malaria parasite? a) euglenazoans b) parabasilids c) apicomplexans d) ciliates

c

In lab class a plasmodial slime mold is used as a demonstration organism. One of the students does not understand why the plasmodium is not considered multicellular. How would you explain it to her? a) Plasmodial slime molds are not able to reproduce sexually, so therefore they are not truly multicellular. b) The distinct cells that make up the mass of cytoplasm do not cooperate, so they do not represent a truly multicellular organism. c) Multicellular organisms are seen only in the kingdoms Animalia and Plantae. d) Although this mass of cytoplasm contains many nuclei, it is not divided by plasma membranes; therefore, it is not technically multicellular.

d

Proteobacteria are all _____ and include Vibrio cholerae, E. coli, and Rhizobium species. a) gram-positive b) photoautotrophs c) predators or parasites d) gram-negative

d

The fantastic organism pictured below would surely qualify for a starring role in a horror film if it were a thousand times larger than it really is. In its active feeding stage, it is a single giant multinucleate cell that slides over moist organic matter, engulfing food particles as it grows. What is it? a) a macroamoeba b) a fungus c) a cellular slime mold d) a plasmodial slime mold

d

Which best describes the protists? a) Protists are early eukaryotes with very simple cells. b) Protists are a monophyletic kingdom of very closely related species of unicellular eukaryotes. c) Protists are a monophyletic kingdom of very closely related species of multicellular eukaryotes. d) Protists are diverse eukaryotes, typically unicellular, that do not fit into the plant, animal, or fungal kingdoms.

d

Which of the following groups of algae is most closely related to higher plants? a) brown algae b) diatoms c) dinoflagellates d) multicellular green algae

d

Which of these organisms all share some form of hard shell, internal skeleton, or mineralized cell wall? a) water molds and diatoms b) diatoms and amoebas c) plasmodial and cellular slime molds d) dinoflagellates, forams, and radiolarians

d

Yersinia pestis causes plague. _____ plague spreads through flea bites, but _____ plague might be used as a biological weapon. a) Pneumonic ... bubonic b) Bubonic ... anthracis c) Bubonic ... cutaneous d) Bubonic ... pneumonic

d

You are an epidemiologist with the Centers for Disease Control investigating a mysterious nervous system disorder. You discover that all of the victims were exposed to the water during a severe bloom of pinkish-orange organisms at local beaches. What group of protists is the likely culprit? a) parabasilids b) euglenazoans c) ciliates d) dinoflagellates

d

_____ are common in fresh water, and many have complex life cycles. a) Cyanobacteria b) Brown algae c) Red algae d) Green algae

d

_____ have specially modified mitochondria that generate some energy anaerobically. One type causes an increasingly common and problematic sexually transmitted disease. a) Euglenazoans b) Ciliates c) Dinoflagellates d) Parabasilids

d

In general, how do algae and protozoans differ? a) Protozoans can move, and algae cannot. b) Protozoans are autotrophic, and algae are heterotrophic. c) Algae are free-living, and protozoans are parasitic. d) Algae are photosynthetic, and protozoans are usually heterotrophic.

d Algae are "plantlike" protists, and protozoans are "animal-like" protists

Secondary endosymbiosis is _____. a) the incorporation of cyanobacteria (eventually chloroplasts) into a eukaryote that already contains mitochondria b) the incorporation of prokaryotes into a larger prokaryotic host cell c) the incorporation of another type of prokaryote into a fully eukaryotic host cell that already contains mitochondria d) the incorporation of red or green algae into a heterotrophic eukaryotic host

d This process is thought to have generated a great deal of diversity in the protists.

Which of the following is an example of a biofilm? dental plaque H. pylori peptidoglycan fimbriae

dental plaque

prokaryotes' two domains

bacteria and archaea

koch's postulates

to test the hypothesis that a certain bacteria is harmful, a researcher much satisfy four conditions; 1) find the candidate bacteria in every case of the disease 2) isolate the bacteria from a person who has the disease and grow it in pure culture 3) show that he cultured bacteria causes the disease when transferred to a healthy subject 4) isolate the bacteria from the experimentally infected subject

diatoms

unicellular algae that are one of the most important photosynthetic organisms on earth; they have a glassy cell wall that contains silica; cell wall consists of two halves; they are both in freshwater and marine environment; produce organic molecules; lipids make the diatoms buoyant which keeps them floating near the surface in the sunlight; thought to be main source of oil

bioremediation

use of organisms to remove pollutants from soil, air, or water; help the sewage treatment facility; also a useful tool for cleaning up toxic chemicals released into the soil and water

mode of nutrition

way to organize the diversity of prokaryotes; how they obtain energy for cellular work and carbon to build organic molecules; prokaryotes exhibit much more nutritional diversity than eukaryotes;

choanoflagellates

A combination of morphological and molecular evidence suggests that choanoflagellates are the closest living protist relative of animals

some archaea are referred to as "Extremophiles" why?

because they can thrive in an environment too hot, too salty, or too acidic for other organisms

amoebas

move and feed by means of threadlike pseudopodia (temporary extensions of the cell);

chemoheterotrophs

acquire both energy and carbon from organic molecules; are by far the largest and most diverse group of prokaryotes; this term describes human mode of nutrition

plasmids

additional small, circular DNA molecules in many prokaryotes; replicate independently of the chromosome; carry genes that enhance survival under certain conditions

archaeplastida

almost all members of this supergroup are autotrophic; red algae, green algae, and land plants

proteobacteria

are all gram negative and share a particular rRNA sequence; great diversity; all four modes of nutrition are present; thiomargarita namibiensis type of photoautotrophic species of proteobacteria that uses H2S to generate organic molecules from CO2 and produces sulfur wastes; also include rhizobium species (endosymbiont) that live symbiotically in root nodules of legumes and convert atmospheric nitrogen gas into a form usable by their legume host;

Flagella function to _____. a) prevent the cell from bursting in a hypotonic environment b) propel the bacterial cell c) attach cells to their substrate or to neighboring cells d) protect the cell from extremely harsh conditions such as boiling temperatures

b

Which best describes a modern sewage treatment plant, one part of which is pictured below? a) It is a mechanical filtration plant where wastewater is forced through various filters that remove progressively smaller particles from the water. b) It is a form of bioremediation in which diverse microbes process waste and remove or decompose pollutants. c) It is based on distillation. Water is boiled, and steam is recovered as pure water; the solids left over are burned. d) It is a chemical facility where powerful chemical disinfectants and artificial enzymes are used to break down wastes and kill bacteria.

b

You are examining a fragment of material from an unknown life-form extracted from a sample taken deep in Earth's crust. Which of the following clues would convince you the sample came from an archaeal cell? a) genes lacking introns b) histones associated with DNA and some introns present in genes, but no evidence of membrane-enclosed organelles c) peptidoglycan in the cell wall material d) membrane-enclosed organelles

b

ciliates

named after their cilia; this group of unicellular protists includes heterotrophs and mixotrophs;

A microbe can be successfully cultured in isolation (no other organisms present) in the dark in a broth that includes only sugar and a few amino acids. What is it? a) a photoautotroph b) a chemoautotroph c) a cyanobacterium d) a chemoheterotroph

d

The bacteria that cause tetanus can be killed only by prolonged heating at temperatures considerably above boiling. This suggests that tetanus bacteria _____. a) have cell walls containing peptidoglycan b) secrete endotoxins c) protect themselves by secreting antibiotics d) produce endospores

d

The capsule and fimbriae function to _____. a) propel the bacterial cell b) prevent the cell from bursting in a hypotonic environment c) protect the cell from extremely harsh conditions such as boiling temperatures d) attach cells to their substrate or to neighboring cells

d

parasites

derive their nutrition from a living host, which is harmed by the interaction

how to identify prokaryotes

determine cell shape by microscopic examination; cell wall (peptidoglycan color);

alveolates

dinoflagellates, ciliates, parasites

pathogens

disease causing agents

protists

diverse collection of mostly unicellular eukaryotes; eukaryotes that are not plants, animals, or fungi

endospore

some prokaryotes have inner cell (endospore); has thick protective coat; dehydrates and becomes dormant; can survive extreme cold and heat; food canning industry kills endospores of dangerous bacteria by heating the food to 110-150 C

protists nutrition

some protists are autotrophs (producing their food through photosynthesis) are called algae; many algae are multicellular; other protists are heterotrophs (protozoans) - they eat bacteria and other protists; some heterotrophic protists are fungus like and obtain organic molecules by absorption and some are parasitic; other protists are mixotrophs- capable of both photosynthesis and heterotrophy depending on availability of light and nutrients

Which properly states the role of bacteria and prokaryotes in general in human life? (see book section: Module 16.1) 1) Prokaryotes cause half of all infectious human diseases. However, they also play vitally important positive roles as decomposers and even as beneficial partners in our bodies. The sudden disappearance of all prokaryotes would almost certainly doom humans to extinction. 2) Prokaryotes are so small that they have relatively little influence on human affairs. A few diseases would disappear, but otherwise we would not notice if prokaryotes disappeared from Earth. 3) Some prokaryotes are parasites and cause half of all infectious human diseases. Therefore, humans would benefit if all prokaryotes disappeared. 4) If all prokaryotes disappeared, humans would benefit. We would have more food because less of it would rot.

1

Prokaryotes called _____ make up a major branch on the tree of life; their cells are similar in many ways to those of eukaryotic organisms. a) archaea b) cyanobacteria c) bacteria d) protozoa

a

Traits of bacteria that are different from those of eukaryotes are often good targets for antibiotic action. Many antibiotics target bacterial _____, which are not present in human cells. a) peptidoglycan cell walls and small ribosomes b) phospholipid plasma membranes c) internal membranes d) endospores

a

extreme halophiles

a group of archaea; salt lovers; thrive in very salty places such as great salt lake, dead sea and seawater evaporating ponds used to produce salt; many species flourish when the salinity of the water is 15-30%;

You have been asked to participate in the cleanup of an old mining site. You build a treatment wetland to clean up a contaminated spring flowing out of the mine area. Before sending the water to the wetland, you pass it through a holding tank where Thiobacillus removes heavy metals. The plants and microbes of the wetland will absorb many of the contaminants that remain in the water. Your method is an example of _____. a) preservationism b) bioremediation c) landscape ecology d) biodiversity maintenance

b

cellular slime molds

common on rotting logs and decaying organic matter; most of the time these organisms exist as solitary amoeboid cells; when food is scarce, they swarm together forming a slug like aggregate that wanders around for short time and then form a stock supporting an asexual reproductive structure that produces spores

what happens in biofilms

communicate by chemical signals; coordinate the division of labor and collectively defend against invaders; channels in the biofilm allow: nutrients to reach cells in the interior; wastes to leave and a variety of environments to develop within it

unikonta

controversial grouping that joins two well established clades: amoebozoans (which are protists) and a second clade that includes animals and fungi

foraminiferans

found both in the ocean and in fresh water; have porous shells (composed of organic material hardened by calcium carbonate) called tests; the psuedopodia which serves in feeding and mobility, extend through small pores in the test; 90% of forams identified are fossils

how does prokaryotes have immense impact on our world?

found wherever there is life (including in and on the bodies of multi-cellular organisms); the biomass of prokaryotes is 10 times that of all eukaryotes; they thrive in habitats too cold, too hot, too salty, too acidic, or too alkaline for any eukaryote;

gram stain

gram positive bacteria have simple walls with thick layer of peptidoglycan; gram negative bacteria have less peptidoglycan and are more complex, with an outer membrane that contains lipids bonded to carbohydrates (toxic); gram negative generally more threatening than gram positive bacteria

green algae

grass green chloroplasts; include unicellular and colonial species as well as multicellular seaweeds; Volvox is a colonial green algae.; Chlamydomonas is a unicellular alga propelled by two flagella.

rapid reproduction generates what in a prokaryote population?

great deal of genetic variation; each time DNA is replicated prior to binary fission, a few mutations occur; population growth occurs through binary fission

extreme thermophiles

group of archaea; heat lovers; thrive in very hot water; one habitat - nevada geyser; other thermophiles thrive in acid;

methanogens

group of archaea; live in anaerobic (oxygen-lacking) environments and give off methane as a waste product; great number of methanogens inhabit the digestive tracts of cattle, deer, and other animals hat depend heavily on cellulose for their nutrition;

prokaryotes

guard body against pathogens; help with digestion; decompose dead skin cells; in soil they help decompose dead organisms and other organic waste material; makes nitrogen available to plants and other organisms;

photoautotrophs

harness sunlight for energy and use CO2 for carbon (cyanobacteria); photosynthesis in cyanobacteria uses chlorophyll a and produces O2 as a by product

chemoautotrophs

harvest energy from inorganic chemicals and use carbon from CO2 to make organic molecules; can thrive on conditions that seem inhospitable because they dont need sunlight; use sulfur compound as source of energy; the organic molecules they produce help support the diverse animal communities; predictable habitats: soil

amoebozoans

have lobe shaped pseudopodia; include many species of free living amoebas, some parasitic amoebas, and slime molds

protist cells

have membrane enclosed nucleus that contains multiple chromosomes and other organelles characteristic of eukaryotic cells;

spirochetes

helical bacteria that spiral through their environment by means of rotating internal filaments; has pathogens that cause syphilis and lyme disease

excavata includes

heterotrophic termite endosymbionts; autotrophic species; mixotrophs such as Euglena; the common waterborne parasite Giardia intestinalis; the parasite Trichomonas vaginalis, which causes 5 million new infections each year of human reproductive tracts; and the parasite Trypanosoma, which causes sleeping sickness in humans.

water molds

heterotrophic unicellular stramenopiles that decompose dead plants and animals in freshwater habitats;

biofilms

highly organized colonies attach to surfaces; may consist of one or several species of prokaryotes and may include protists and fungi as well; can form on any support including rocks, soil, organic material, metal, plastic, and stagnant water; common among bacteria that cause disease in humans;

chronic gastritis

inflammation of the stomach lining that can lead to ulcers; barry marshall hypothesized that this was caused by H pylori (bacteria)

brown algae

large complex stramenopiles; color formed by pigments in chloroplasts; all are multicellular and most are marine; seaweeds;

how do biofilms form

prokaryotes produce signaling molecules that attract nearby cells into cluster. once the cluster becomes large enough, the cells produce a gooey coating that glues them to the support and to each other;

endotoxins

lipid components of the outer membrane of gram negative bacteria that are released when the cell dies or is digested by a defensive call; same general symptoms: fever, aches, and sometimes dangerous drop in blood pressure (septic shock);

chlamydias

live inside eukaryotic host cells; common cause of blindness in developing countries;

red algae

majority of them are in warm coastal waters; few are unicellular most are multicellular; are typically soft bodied but some have cell walls encrusted with hard chalky deposits; contribute to the structure of coral reefs;

as different as bacteria and archaea are, both groups are characterized by _________ cells, which lack a nuclei and other membrane enclosed organelles

prokaryotic

chemotrophs

prokaryotic chemotrophs get the energy stored in chemicals, either organic or inorganic;

phototrophs

prokaryotic phototrophs get energy from sunlight; prokaryotic cells do not have chloroplasts but some prokaryotes have thylakoid membranes where photosynthesis takes place

cyanobacteria

only group of prokaryotes with plant like, oxygen generating photosynthesis; provides food for freshwater and marine ecosystems; have symbiotic relationships with organisms such as fungi, mosses, and a variety of marine invertebrates; some species (Anabaena) can fix nitrogen

autotrophs

organisms that make their own organic compound from inorganic sources; this includes plants and some prokaryotes and protists; autotrophs obtain their carbon atoms from carbon dioxide; most prokaryotes, as well as animals, fungi and some protists, are heterotrophs (they obtain their carbon atoms from the organic compounds of other organisms)

source of energy of prokaryotes

phototrophs; chemotrophs

exotoxins

proteins that bacterial cells produce into their environment; some of the most powerful poisons known;

domain bacteria is currently divided into 5 groups based on comparisons in their gene sequence. what are these groups?

proteobacteria;

plasmodial slime mold

protists are common where there is moist decaying organic matter and are often brightly pigmented; not multi cellular; is plasmodium (single multinucleate mass of cytoplasm undivided by plasma membranes); used to study molecular details of the cell cycle because most of the nuclei go through mitosis at the same time

cell walls

provide physical protection; prevent the cell from bursting in hypotonic environment

endosymbiosis

refers to one species called the endosymbiont (living within another)

bacilli

rod shaped prokaryotes; mostly occur singly but can be in chains

gram positive bacteria

second major group of bacteria;

excavata

second supergroup in the survey of protists, has been proposed as a clade on basis of molecular and morphological similarities; have modified mitochondria that lack functional electron transport chains

cocci

spherical prokaryotic cells; cocci that occurs in chains is called streptococci;

spirochete

spiral prokaryotic cell; short and rigid (spirilla); those with long and flexible cells are called spirochetes

SAR

stramenopila, alveolata, rhizaria; three clades that make up protist;

which groups of stramenopila, alveolata, and rhizaria include autotrophs?

stramenopila: diatoms, brown algae; alveolata: dinoflagellates; rhizaria: none

radiolarians

support internal skeleton made of silica; cell is surrounded by test composed of organic material; most are marine;