BIO 212 Q6

malaria arc

What two domains are prokaryotes divided into?

bacteria and archaea

Prokaryotes thrive ___

almost everywhere

Most prokaryotes are ___

unicellular

What are the three most common shapes (colonies)?

spheres (cocci), rods (bacilli), and spirals

spheres

cocci

rods

bacilli

An important feature of nearly all prokaryotic cells is their

cell wall

What is a cell wall made out of?

cellulose or chitin

What is the function of the cell wall?

maintains cell shape and protects the cell

Scientists use the **___** to classify bacteria by cell wall composition

gram stain

What color is a gram-positive bacteria?

Purple

Gram-positive bacteria have simpler walls with a

large amount of peptidoglycan

What color is a gram-negative bacteria?

Pink

Gram-negative bacteria have

less peptidoglycan and a toxic outer membrane

Many antibiotics target ____ and damage bacterial ___

peptidoglycan, cell walls

gram-negative bacteria are more likely to be

antibiotic resistant

Most motile bacteria propel themselves by

flagella

Many of the flagella’s proteins are

modified versions of proteins that perform other tasks in bacteria

exaptation

existing structures take on new functions through descent with modification

The prokaryotic genome has less DNA than the

eukaryotic genome

Most of the prokaryotic genome consists of a

circular chromosome

Where is the chromosome located?

nucleoid region

plasmids

smaller rings of DNA that some bacteria have

Key feature of prokaryotic reproduction (1)

They are small

Key feature of prokaryotic reproduction (2)

reproduce by binary fission

Key feature of prokaryotic reproduction (3)

have short generation times \[1-3 hours\]

What are the three factors that contribute to prokaryotic genetic diversity?

rapid reproduction, mutation, genetic recombination

Mutation rates during binary fission are low, but because of rapid reproduction

mutations can accumulate rapidly in a population

high diversity from mutations allows for

rapid evolution

Prokaryotic DNA from different individuals can be brought together by

transformation, transduction, conjugation

transformation

A prokaryotic cell can take up and incorporate foreign DNA from the surrounding environment

Transduction

the movement of genes between bacteria by bacteriophages (viruses that infect bacteria)

Conjugation

the process where genetic material is transferred between prokaryotic cells

genetic material is transferred through the

sex pilus

Prokaryotes can be categorized by how they obtain

energy and carbon

Phototrophs

obtain energy from light

Chemotrophs

obtain energy from chemicals

Autotrophs

require CO2 as a carbon source

Heterotrophs

require an organic nutrient to make organic compounds

Obligate aerobes

require O2 for cellular respiration

Obligate anaerobes

poisoned by O2

What processes do obligate anaerobes use?

fermentation or anaerobic respiration

Facultative anaerobes

can survive with or without O2

What led to the splitting of prokaryotes into bacteria and archaea?

Molecular systematics

Archaea share

certain traits with bacteria and other traits with eukaryotes

extremophiles

archaea that live in extreme environments

extreme halophiles

live in highly saline environments

extreme thermophiles

thrive in very hot environments

What does *Chlamydia trachomatis* cause?

Blindness

What does *Borrelia burgdorferi* cause?

Lyme disease

Plant chloroplasts likely evolved from

cyanobacteria

cyanobacteria

photoautotrophs that generate O2

Plant chloroplasts likely evolved from cyanobacteria by the process of

endosymbiosis

Prokaryotes play a major role in the ___ between the living and nonliving components of ecosystems

recycling of chemical elements

Chemoheterotrophic prokaryotes function as

decomposers

Symbiosis

ecological relationship in which two species live in close contact

prokaryotes often form symbiotic relationships with

larger organisms

mutualism

both symbiotic organisms benefit

commensalism

one organism benefits while neither harming nor helping the other in any significant way

parasitism

organism harms but does not kill its host

pathogens

parasites that cause disease

vectors

parasites that transmit disease

Prokaryotes are the principal agents in

bioremediation

bioremediation

the use of organisms to remove pollutants from the environment

The Romans thought the malaria was caused by

bad air from swamps

What did the Romans do to prevent malaria?

drain swamps

Malaria can be

asymptomatic

What are the classic symptoms of malaria?

fever, chills, sweating, headaches, muscle pains

What are the severe symptoms of malaria?

cerebral malaria, anemia, kidney failure

What factor affects the severity of symptoms? (1)

the species of Plasmodium

What factor affects the severity of symptoms? (2)

the victims genetic background

What factor affects the severity of symptoms? (3)

acquired immunity

Who discovered malaria?

Charles Laveran

Who discovered the mode of transmission of malaria?

Ronald Ross

What is the mode of transmission of malaria?

Anopheles mosquito

What are the four species of Plasmodium that causes malaria?

P. falciparum, P. vivax, P.ovale and P. malariae

P. falciparum cases are often

fatal and is responsible for most deaths

Both ___ and ___ can go dormant, hiding out in the liver

*Plasmodium vivax*, *P. ovale*

P. malariae causes a

long-lasting infection

Plasmodium has two hosts:

mosquitoes and humans

Where does sexual reproduction take place?

In the mosquito

When is malaria transmitted to humans?

when the mosquito takes a blood meal

In the salivary gland the parasite cuts off the mosquito’s

anticoagulant supply

What does cutting off the anticoagulant supply do?

this makes it harder for the mosquito to feed

As a result of the anticoagulant

an infected mosquito is twice as likely to bite two people in a single night as an uninfected mosquito

parasite is spread more widely

In humans, the Plasmodium helps the mosquito feed by

releasing chemicals that slow clotting

What does slowed clotting do?

increase the chances of the mosquito feeding successfully and sucking up the parasite