bio hw 1,2,3
A saprobe is an organism that ________.
lives off decaying matter
Which property of water allows dogs to cool themselves by panting?
water's high heat of vaporization
Which of the following statements about the formation of polypeptides from amino acids is true?
A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.
Which of the following is not attached to the central carbon atom in an amino acid?
An oxygen
Which of the following hydrocarbons has a double bond in its carbon skeleton?
C2H4
Which part of an amino acid is always acidic?
Carboxyl functional group
True or false? Enzymes in the digestive tract catalyze hydrolysis reactions.
T
Which property of water allows a water strider to walk on water?
Water's high surface tension
The large diversity of shapes of biological molecules is possible because of the extensive presence of _____ in the molecules.
With four electrons to share, carbon-based molecules can be multibranching and three-dimensionally variable.
which property of water allows a paper towl to pick up a puddle of water?
adhesion of water molecules to other kinds of molecules. Water adheres to the cellulose molecules in a paper towel, allowing the towel to pick up a puddle of water.
Prokaryotes convert atmospheric nitrogen to the biologically available compound __________ in a process known as nitrogen fixation.
ammonia
The central carbon atom in an amino acid is bonded to...
an amino functional group, a carboxyl functional group, a side chain, and hydrogen
Which of these individuals is likely to be most successful in an evolutionary sense?
an organism that dies after five days of life but leaves 10 offspring, all of whom survive to reproduce
You isolate a strain of bacteria and find that it obtains its carbon from carbon dioxide and its energy from complex carbon. It can be categorized as a ___________.
chemoautotroph
An organism that uses chemicals from the environment as an energy source is a ____________.
chemotroph
About 10% (or more) of us carry Stapylococcus aureus on our skin as part of our normal flora. Upon wounding, these bacteria can invade the bloodstream and lead to a variety of diseases. This is one example of an opportunistic infection. If you are one of the 10% affected and have no disease symptoms at this time, then this symbiosis is categorized as a ________.
commensalistic symbiosis
The tendency of an atom to pull electrons toward itself is referred to as its _____.
electronegativity
Each water molecule is joined to _____ other water molecules by ____ bonds.
four ... hydrogen
The relationship between a legume and bacteria in its root nodules is best described as ________________.
mutualism
Which monomers make up RNA?
nucleotides
Which of the following features can be used to distinguish bacteria from archaea?
one has genes that appear more eukaryotic in character
Eubacterial cell walls differ from eukaryotes' cell walls in that they have _____________________.
peptidoglycan
The unequal sharing of electrons within a water molecule makes the water molecule _____.
polar
A motile bacterium that moves toward light is displaying ____________.
positive phototaxis
Which polymers are composed of amino acids?
proteins