Ch. 13.1 Prokaryotes

List three main differences between Bacteria and Archaea.

1) Genes in archaea have introns

The common prokaryotic shapes include helices, _____________, and rods.

Spheres

Identify the three most common shapes of prokaryotic cells.

The three most common shapes of prokaryotic cells are the helix, sphere, and rod.

What is the role of endospores in prokaryotes?

Unlike organisms who might form spores for reproduction, some prokaryotes form spores for survival. These endospores form inside prokaryotic cells when they are under stress. (UV radiation, high temperatures, or harsh chemicals) Endospores enclose the DNA and help it survive under conditions that may kill the cell.

antibiotic resistance

a disease or sickness that cannot be treated with antibiotics because the bacteria is immune to the medicine

antibiotic drug

a drug that can cure bacterial infections

genetic transfer

a way prokaryotes increase genetic variation. can occur when cells "grab" stray pieces of DNA from their environment or when cells directly exchange DNA (usually plasmids) with other cells

vector

an organism that spreads pathogens from host to host

cyanobacteria

contain chlorophyll, make food through photosynthesis, & were probably responsible for adding oxygen to the air on early earth

bacteria

domain of prokaryotes that can cause human diseases

endospore

formed by prokaryotes under stress (UV radiation, high temperatures, or harsh chemicals) to enclose the DNA and help it survive in harsh conditions which may kill the cell

plasmid

small, circular pieces of DNA

flagella

thin protein structures which extend from the plasma membrane of prokaryotes and help them move

gram positive bacteria

type of bacteria that stain purple with gram stain and have a thick cell wall without an outer membrane

gram-negative bacteria

type of bacteria that stain red with gram stain and have a thin cell wall with an outer membrane

Under ideal conditions, bacterial populations can double every _____ minutes.

20

What is a domain? What are the three domains of life?

A domain is the largest taxonomical group and the three domains of life are eukarya, archae and bacteria.

Bacterial infections in people can be treated with ____________ drugs.

Antibiotic

____________________ live everywhere on Earth, including extreme environments such as deep sea vents.

Archaebacteria

Prokaryotes reproduce through binary fission, a type of _________________ reproduction.

Asexual

The prokaryote domains are _____________ and _____________.

Bacteria & Archae

List several benefits of bacteria.

Bacteria provide vital ecosystem services. They are important decomposers and are needed in the carbon and nitrogen cycles. They help digest food, make vitamins, and are used by humans in ways such as creating products (ethanol and enzymes,) making drugs (antibiotics and vaccines,) making biogas (methane,) cleaning up oil spills and toxic wastes, killing plant pests, transferring normal genes to human cells in gene therapy. fermenting foods.

What is an extremophile?

Bacteria that can live in extreme conditions.

There are __________________ of bacteria inside the human intestines that help digest food.

Billions

A _________________ is a colony of prokaryotes that is stuck to a surface such as a host's tissues.

Biofilm

Prokaryotes have a ___________ ___________ outside their plasma membrane, usually to give strength and rigidity to the cell.

Cell wall

Bacteria called ______________ make food through photosynthesis and release oxygen into the air.

Cyanobacteria

A plasmid is an extra-chromosomal piece of _______________.

DNA

What are extremophiles? Name three types.

Extremophiles are Archaea who live in extreme environments. Three types of extremophiles are halophiles (salt), hypothermophiles (heat), and acidophiles (acid).

(T/F) Bacteria in food or water usually cannot be killed

False

(T/F) Because they are simple single cells, prokaryotes do not need energy

False

(T/F) Prokaryotic DNA is usually one or two circular chromosomes

False

(T/F) The most common prokaryotic shapes are helices (spirillus), polygons, spheres (coccus), and rods (bacillus)

False (not polygons)

(T/F) Bacteria provide vital ecosystem services - they are important producers and are needed for the carbon and nitrogen cycles

False (they are not producers)

(T/F) Since prokaryotes do not have organelles, they do not have ribosomes

False (they do not have organelles but they do have ribosomes)

What is the role of flagella in prokaryotes?

Flagella help prokaryotes move as they spin around a fixed base, causing the cell to roll and tumble.

Why might genetic transfer be important for the survival of prokaryote species?

Genetic transfer is important for the survival of prokaryote species because it increases genetic variation. Lack of genetic variation increases the risk of extinction because without it, there may be no organisms that can survive a major change in the environment.

Cellular respiration and photosynthesis take place in the plasma ___________________ of prokaryotes.

Membrane

The DNA of a prokaryotic cell is in the cytoplasm because the cell lacks a _____________.

Nucleus

What are prokaryotes?

Prokaryotes are tiny single-celled organisms that lack a nucleus and other membrane-bound organelles. They are also the most numerous organisms on Earth.

Give three examples of places bacteria live.

The ocean, the soil, and in the intestines of animals.

Genetic _________ increases genetic variation in prokaryotes.

Transfer

(T/F) Aerobic prokaryotes need oxygen, which they use for cellular respiration

True

(T/F) Both Bacteria and Archaea have plasma membranes and cell walls

True

(T/F) Cyanobacteria contain the organelle chlorophyll

True

(T/F) Cyanobacteria were probably the first organisms to photosynthesize

True

(T/F) Flagella help bacteria move

True

(T/F) Insects are common vectors for spreading bacterial diseases between humans.

True

(T/F) Prokaryotes are single-celled organisms that lack a nucleus

True

(T/F) The first Archaea discovered were the extremophiles

True

(T/F) There are billions of bacteria inside the human intestines that help digest food

True

extremophile

archae that can live in extreme environments

biofilm

colony of prokaryotes that is stuck to a surface such as a rock or a host's tissues

archaea

one of the two prokaryotic domains that has organisms that live in extreme environments