Biology Chapter 17-2 b
How are animals such as cattle dependent upon the symbiotic relationship they have with bacteria in their intestines?
No vertebrate can produce enzymes necessary to break down cellulose, the principle carbohydrate in grass and hay, but the bacteria in their digestive systems make these enzymes, allowing them to digest their food properly.
How is the relationship between us and the bacteria in our intestines a symbiotic relationship we both benefit from?
The bacteria are provided with good living conditions (warm, plenty of food, free transportation) and we get help with digestion of our food, as well as vitamins that we cannot produce on our own.
While the soybean provides a home for the bacteria Rhizobium, how does the soybean benefit?
The bacterium fixes nitrogen directly from the air into ammonia for the plant
What is added to directly to sewage waste water? Why?
a diverse mixture of bacteria, they break down the complex compounds in the sewage into simpler compounds, producing purified water + nitrogen gas + carbon dioxide gas + leftover products (sometimes used as crop fertilizers)
How is genetic information transferred during conjugation?
a long bridge of protein forms between and connects two bacterial cells, part of the genetic information from one cell (the donor) is transferred to the other cell (the recipient) through this bridge.
Living organisms generally require that Nitrogen be "fixed" chemically in the form of
ammonia (NH3) and related nitrogen compounds.
In the most favorable conditions, at what rate can bacteria reproduce?
as often as every 20 minutes
Why is binary fission asexual reproduction?
because it does not involve the exchange or recombination of genetic information
What are the two ways bacteria reproduce?
binary fission and conjugation
What are some foods that bacteria are used in their production?
cheese, yogurt, buttermilk, and sour cream, pickles, sauerkraut, vinegar (made from wine)
What is an example of an obligate anaerobe? Where is it often found? Why does it normally cause very few problems?
clostridium botulinum, in soil, because it is unable to grow in the presence of oxygen
What clues point to staphylococci as source of food poisoning? Why?
diarrhea, vomiting, nausea, abdominal cramps within a few hours of eating tainted food, recovery within 24-48 hours---the toxin produced by staphylococci is secreted into the food source and enters bloodstream upon digestion
Organisms that can survive with or without oxygen are known as ____________________.
facultative anaerobes.
The process that enables cells to carry out energy without oxygen is called _________.
fermentation.
The ability to ___________________ makes it possible for some bacteria to survive harsh conditions that would otherwise kill him.
form spores
When growth conditions become unfavorable, many bacteria ......
form structures called spors
What is the perfect environment for growth of clostridium botulinum?
in canned food, especially food canned at home where it is less likely safety measures are ensured to heat things to proper temperatures
Why is synthetic nitrogen containing fertilizers not feasible?
it is expensive, time-consuming, and sometimes dangerous
Where does the species name coli come from?
it was derived from the fact that these bacteria were discovered in the human colon (large intestine)
An endospore is formed when a bacteria produces a thick internal wall that encloses ____________________.
its DNA and a portion of its cytoplasm.
All plants benefit from the nitrogen fixing ability of _____________, but soybeans are a step ahead with Rhizobium acting like ____________
monerans, a built in fertilizer factory
What are the results of botulism?
nerve activity is interfered and sometime paralysis results, if breathing muscles are paralyzed=death
What are all organisms on our planet totally dependent on bacteria for?
nitrogen (plants need to make amino acids to make proteins----animals eat plants and get protein, which essentially came from nitrogen produced by bacteria)
Organisms that requires a constant supply of oxygen in order to live are called ___________________. Example?
obligate aerobes. Humans
Organisms that must live in the absence of oxygen are called _______________.
obligate anaerobes.
Where and in what form does Rhizobium grow on the soybean plant?
on the roots, in knobs or nodules
What is ultimately the source of proteins for animals?
plants (bc animals that get protein from animals that got protein from plants)
Some bacteria do not require oxygen, and may actually be ____________________
poisoned by it.
What is conjugation?
process in bacteria and protists that involves an exchange of genetic information
The constant supply of energy that bacteria need to perform all their life activities is supplied by the processes of _____________.
respiration and fermentation.
The process that involves oxygen and breaks down food molecules to release energy is called ____________.
respiration.
While bacteria play a major role in the process of digesting dead organisms and breaking them down into simpler substances, what organisms play a supporting role in this process?
some eukaryotic organisms such as insects and fungi.
What clues point to salmonella as source of food poisoning? Why?
symptoms don't show for 12+ hours, diarrhea, fever, chills, frequent vomiting, abdominal pain. Much longer recovery.---The toxin of salmonella is contained in the cell walls and is only released when the bacteria lyse, so takes longer to see symptoms.
In nature, the growth of bacteria is held in check by .....
the availability of food and the production of waste products.
How does conjugation effect the population of bacteria?
the new combination of genes increase the genetic diversity in that population, ensuring that even if the environment changes, a few bacteria may have right genes to survive
What is an example of a plant that has a symbiotic relationship with a nitrogen fixing bacteria? What is the bacteria called?
the soybean, Rhizobium
What do all green plants need nitrogen for?
to make amino acids, the building blocks of proteins
Unlimited space and food for all bacterium + all divided every 20 minutes=
total mass 4,000 times the mass of the earth in 48 hours
What is binary fission?
type of asexual reproduction in which an organism divides to produce two identical daughter cells
Saprophytes are organisms that ......
uses the complex molecules of a once-living organism as their source of energy and nutrition.
What are some examples bacteria used in industry?
1) bacteria that can digest petroleum--clean up oil spills 2) remove waste products and poisons from water 3) mine minerals from the ground 4) synthesize drugs and chemicals via genetic engineering
What questions help a medical detective determine which bacteria, particularly between salmonella and staphylococci, caused a case of food poising?
1) foods eaten in last 24 hours? 2) where food was eaten 3) timeframe for symptoms to start after eating 4) fever? 5) chills?
_________________ tons of nitrogen are released into the environment every year because of nitrogen-fixing bacteria.
170 million!
Our atmosphere is produced of approximately __ percent of Nitrogen (N2)? Do plants use the nitrogen in the atmosphere? Do other organisms use the nitrogen in the atmosphere?
80, no, no
What is symbiosis?
A close relationship between two species in which at least one species benefits from the other
What is an endospore?
A type of spore formed when a bacteria produces a thick internal wall that encloses its DNA and a portion of its cytoplasm.
Bacteria form symbiotic relationships with organisms from which kingdoms?
All of the eukaryote kingdoms
___________________ recycle and decompose, or break down, dead material.
Bacteria
What happens when a bacterium has grown so that it has nearly doubled in size?
It replicates its DNA and divides in half= two identical daughter cells.
What is the purpose of the endospore?
The endospore can remain dormant for months or years, waiting for more favorable growth conditions, at which point it will open and the bacterium will begin to grow again.
What is nitrogen fixation?
The process where bacteria take nitrogen from the air and convert it to a form that plants can use.
What happens when saprophytes attack and digest the dead wood of a fallen tree (or another dead organism)?
They break down the substance into simpler substances, enriching the soil in which it grew.
When clostridium botulinum find their way into a place that is free of air (which contain O2) what happens?
They grow very quickly and produce "toxins" (poisons) that cause botulism.
