final pt 1 Flashcards
All living organisms share five fundamental characteristics. Which of the following is not one of these characteristics?
sexual recombination
Pasteur’s experiment provided conclusive evidence to reject the spontaneous generation hypothesis, which states that cells arise from nonliving material. As a consequence, his results supported the all-cells-from-cells hypothesis. Which element of Pasteur’s experimental design was most important and why?
His two treatments differed only in the shape of the flask, resulting in exposure of only one of the treatments
to preexisting cells.
The feature of an experiment that is changed from one treatment to the next is referred to as a:
variable
In the diagram below, “A” is _____ ; “B” is _____.
the common ancestor of all life; the common ancestor of Archaea and Eukarya
Which of the following statements is true about biological studies
Hypotheses may be tested by a combination of observation, measurement, and experimentation
Which one of the following elements is found in nonliving systems but not found in more than trace amounts in living systems?
silicon
Which one of the following nucleotides hydrogen base pairs with adenine in an
RNA molecule
Uracil
Imagine you have discovered a new species of bacteria. To begin your investigation of this organism, you run an assay on the total nucleotide content of the bacterial cells. If the cytosine content of DNA from the bacterial cells is 17%, what is the adenine content?
33%
The strands in a DNA molecule are:
antiparallel
An exon is _______________________
a part of an intact, mature mRNA that leaves the nucleus
Transcription continues until:
a terminator sequence is encountered.
How do phospholipids interact with water molecules?
The polar heads interact with water; the nonpolar tails do not.
The term phospholipid can best be described by which of the following?
a nonpolar lipid molecule that is made amphipathic by the addition of a phosphate
Which aspect of phospholipids is most important to the formation of bilayers?
They are amphipathic
Which of the following crosses lipid bilayers the fastest?
a small, nonpolar molecule like oxygen .O2.
Which of the following is true of osmosis?
n osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher
solute concentration
The Golgi apparatus has a polarity, or sidedness, to its structure and function. Which of the following statements correctly describes this polarity?
All of the listed responses correctly describe polarity characteristics of the Golgi function.
What aspects of amino acid structure vary among different amino acids?
the components of the R-group
Two major types of protein secondary structures are referred to as:
α helix and β sheet
When the peptide bond is created between amino acid 1 and amino acid 2:
the carboxyl group of amino acid 1 is joined to the amino group of amino acid 2
The function of a protein is dependent upon the shape into which the chain of amino acids folds. Many noncovalent interactions are responsible for maintaining the protein’s shape. Assume you have isolated a protein from an organism in its proper shape, and you have treated it with an enzyme that selectively breaks only the peptide bonds in the proteins. Would the protein retain its shape under these conditions?
No; whereas the noncovalent bonds determine the shape of a protein, the peptide bonds are required to
hold the amino acids together.
Which one of the following can contribute to a protein’s tertiary structure?
All of these choices are correct
Translation requires _____.
mRNA, tRNA, and rRNA
How many electrons are involved in a double covalent bond?
4
Which of the following is a violation of the first law of thermodynamics?
The universe will eventually die, and it will have no energy left in it.
Water also has several remarkable properties, largely due to its ability to form hydrogen bonds. Which property does NOT apply to water?
All of the above are properties of water
The energy of movement is called __________ and produces an_______________ reaction.
kinetic energy; exothermic reaction
Why do chemical reactions tend to speed up when the concentration of the reactants is increased?
The reactants collide more often
The unique properties of water are due to the ________________ of water molecules and the ability of water to form _______________ with other water molecules and with other polar molecules.
polarity; hydrogen bonds
Which of the following best explains why “carbs” (carbohydrates) are advertised by manufacturers of candy bars and sports drinks as a “quick energy boost”?
Carbs are reduced molecules that have high-energy electrons.
Nucleic acids have a definite polarity, or directionality. Stated another way, one end of the molecule is different from the other end. How are these ends described?
One end has an unlinked 3 carbon; the other end has an unlinked 5 carbon
Dairy cattle were unknown in Thai culture until recently, and 97% percent of Thai people are lactose intolerant as adults. Which explanation for such widespread lactose intolerance is most likely correct?
Evolutionarily, producing an enzyme to break down a sugar that will never be encountered is wasteful.
