Bio- Chapter 16

There are four bacteria in an egg salad that is left out at room temperature. After two hours, how many bacteria will be in the egg salad?

256

In general, how do algae and protozoans differ?

Algae are photosynthetic, and protozoans are usually heterotrophic.

Which of the following constitutes the use of a biological weapon?

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.

Which best describes the protists?

Protists are diverse eukaryotes, typically unicellular, that do not fit into the plant, animal, or fungal kingdoms.

People who produce very little saliva often have more cavities. What is the best explanation for this?

Since saliva normally helps neutralize acid and replace minerals on teeth, a lack of saliva leads to more cavities.

Which of the following is true? Heart disease causes periodontal disease. There is a correlation between periodontal disease and heart disease. Periodontal disease causes heart disease. Heart disease is caused by the presence of bacteria in the blood.

There is a correlation between periodontal disease and heart disease.

__________ has specially modified mitochondria that generate some energy anaerobically. Moreover, it causes an increasingly common and problematic sexually transmitted disease.

Trichomonas vaginalis

True or false. Bacteria reproduce by an asexual process in which one parent cell gives rise to identical daughter cells.

True

Which of the following is the eukaryotic supergroup that contains fungi and animals? SAR Unikonta Archae plastida Excavata

Unikonta

Which of the following organisms is a prokaryote?

a bacterium

Antibiotics exploit differences in structure between prokaryotes and eukaryotes in order to selectively attack pathogenic bacteria without affecting the human host. A key unique feature of bacteria that is targeted by antibiotics is __________.

a cell wall containing peptidoglycan

Which structure helps bacteria to attach within the tissues that they will infect?

Capsule

Why does the post-Medieval skull in the video have such bad teeth?

Diets during this time period were high in sugar.

______________ evolved from _____________.

Eukaryotes; prokaryotes

According to this phylogenetic tree, which of these pairs of prokaryotic subgroups share the most recent common ancestor?

Euryarchaeota ... Crenarchaeota

A microbe can be successfully cultured in the dark in a broth that includes only sugar and a few amino acids. What type of metabolism does it have?

a chemoheterotroph

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 plasmodial slime mold

What modes of nutrition are found in prokaryotes?

a. carbon dioxide b. cyanobacteria c. sunlight d. organic compounds e. chemicals f. carbon dioxide g. chemicals h. predatory bacteria

What are the external features of prokaryotes?

a. cell wall b. flagella c. fimbriae d. cocci e. bacilli f. spirochete g. positive h. negative

What is the direct cause of demineralization of the enamel on teeth?

acids produced by bacteria

Which of the following are heterotrophic protists? chlamydia samoebas diatoms brown algae

amoebas

Which of the following can increase your risk of atherosclerosis?

avoiding exercise

Organisms that can cause nongonococcal urethritis are classified with _____.

chlamydias

After a long period of coevolution, the photosynthetic bacterium consumed by the predatory cell became the cellular organelle known as the:

chloroplast

Choanoflagellates are single-celled protists with a collar-like structure that resemble cells called choanocytes in sponges. This resemblance most likely reflects _____.

common ancestry; choanoflagellates are probably a sister group closely related to the animals

A student finds some sea lettuce on the beach and wants to know if she is looking at the sporophyte or gametophyte stage. To find out, she would need to __________.

count the chromosomes within a cell undergoing mitosis

The prokaryotic cells that built stromatolites are classified as _____.

cyanobacteria

The prokaryotic cells that were the first to add significant quantities of oxygen to Earth's atmosphere are classified as _____.

cyanobacteria

What group of protists is thought to be the main source of Earth's oil deposits?

diatoms

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 _____.

dinoflagellates

In the part of the cycle shown in blue, after the fusion of gametes, the chromosome number is ________.

diploid

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 _____.

endospores

Some American soldiers serving in Iraq have become infected with a skin disease caused by a protist called Leishmania, which is transmitted by sand flies. The Leishmania organism bears flagella with a unique crystalline rod structure. One of its life stages is squiggly and worm-like in appearance, much like its relative in the same group, Trypanosoma. Leishmania belongs to the group __________.

excavata

Prokaryotes found inhabiting the Great Salt Lake would be _____.

extreme halophiles

Each multicellular alga shown at the top of the diagram is called a ________.

gametophyte

Streptococcus aureus is classified with _____.

gram positive bacteria

In the part of the cycle shown in tan, the chromosome number is _________.

haploid

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?

histones associated with DNA and some introns present in genes, but no evidence of membrane-enclosed organelles

The important distinction between prokaryotes and eukaryotes is that prokaryotes ________ a nucleus, whereas the cells of eukaryotes ________ a nucleus.

lack; have

Spores are produced by the process of __________ .

meosis

After a long period of coevolution, the aerobic bacterium consumed by the predatory cell became the cellular organelle known as the:

mitochondrion.

Which of the following groups of algae is most closely related to higher plants?

multicellular green algae

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?

peptidoglycan in the cell wall material

What is the direct cause of gum disease?

plaque formed by bacteria

Ancient cyanobacteria, found in fossil arrangements called stromatolites, were very important in the history of life because they _____.

produced the oxygen gas in the atmosphere

By far the most abundant and widespread organisms on Earth are the _____.

prokaryotes

The chemoheterotroph Proteus vulgaris is a rod-shaped bacterium classified with _____.

proteobacteria

Dentists sometimes give a patient antibiotics after a teeth-cleaning procedure, especially if the patient is older or has heart disease. What is the best explanation for this?

Antibiotics help kill the bacteria that move from the mouth to the bloodstream, and prevent the bacteria from contributing to atherosclerosis. Submit

Eukaryotes are most closely related to which of the following prokaryotic groups?

Archaea

____________ are organisms that live in extreme environments, such as hot springs.

Archaea

Bacterial _____ are at work in the slimy feel of an underwater rock, ear infections, and dental plaque.

Biofilms

Pea vines grow better and have better access to nitrogen if the seeds are coated with a fine black powder sold by nurseries. This powder might contain __________.

bacteria to help the pea plants fix nitrogen

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 _____.

bioremediation

Spiral-shaped bacteria are likely to be placed with _____.

spirochetes

The multicellular alga shown at the bottom of the diagram is called a _________.

sporophyte

Koch's postulates are the steps used to demonstrate __________.

that a particular microorganism is the cause of a particular disease

The bacteria initially persist in the predatory cell because:

the predatory cell is unable to digest the bacteria.

The newly defined protist group SAR consists of __________.

unicellular and multicellular autotrophic algae and unicellular heterotrophs and mixotrophs

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 _____."

watch how it moves