2208-BIOL-1333-001 exam #1

what is the charge of an atom that has 10 protons and 8 electrons?

+2

the atomic mass of neon is 20. this means it has

10 protons and 10 neutrons

a cell membrane has ___ layers of phospholipids

2

a magazine has published a short piece on a study evaluating the relationship between alcohol consumption and liver cancer. by evaluating the responses of 200 alcohol drinkers, the study determines that 20% (40 individuals) eventually developed liver cancer, whereas the remaining 80% (160 individuals) did not. what was the sample size used in this study?

200

say you tested three green jackets in your experiment and obtained the following temperatures: 27.5 27.2 28.1 what is the mean temperature of the jackets?

27.6

most of the general public relies on media reports for their scientific information

TRUE

viruses reproduce by infecting a host cell and hijacking its cellular machinery to make copies of itself

TRUE.

what is the best explanation of a placebo?

a fake treatment

enzymes can lose their shape if they are placed in an environment that is hotter than normal. how does this help explain why a high fever can be so dangerous?

a high fever can cause enzymes to lose shape, so that they can no longer catalyze chemical reactions.

the presence of absence of ___ differentiates prokaryotic cells from eukaryotic cells

a nucleus

the most accurate and reliable presentation of scientific results (data) would be found ___

in a peer-reviewed scientific journal such as the new england journal of medicine

a substance that increases the hydrogen ion concentration of a solutions is a(n)

acid

a researcher is trying to culture mouse embryonic stem cells, and is providing them with glucose (sugar) as a food source. in order for these cells to survive in culture, he must also add a mixture of essential amino acids to the culture medium. these essential amino acids are ___

amino acids that can't be synthesized (directly) by mouse cells

in the process of digestion, proteins are broken down into ___, whereas carbohydrates are broken down into ___

amino acids; monosaccharides

which of these occurs when caffeine is used in excess of the recommended safe dose?

anxiety

the number of proteins and element has is its ____, whereas the number of electrons will determine ___

atomic number; the type of bond it can form

the amount of energy contained in food is measured in

calories

which of the following was used in the virtual lab experiment to determine the calories in each food item?

calorimeter

a researcher wants to develop a randomized clinical trail that will determine the relationship between an aspirin regimen and heart health. to this end, he decides he will have two groups of patients- one that receives baby aspirin daily, and one that receives a placebo daily. in this scenario, the group of individuals that receives the placebo is the ___ group, and the group that's receives the baby aspirin is the ___ group

control; experimental

which of the following is an appropriate hypothesis for the virtual lab experiment?

darker color material will absorb more heat than lighter colored materials

which of these may be used as a placebo in an experiment designed to test whether caffeinated coffee improves memory?

decaffeinated coffee

which solute is least likely to cross a membrane by simple diffusion?

dissolved sodium ions

you have performed a thorough literature review, and have found some studies supporting correlations between drug use and neurological diseases, weight gain, and brain cancer. based on these correlations, what can you conclude regarding drug use?

drug use may cause neurological diseases, weight gain, and brain cancer

atoms are made up of which three particles?

electrons, neutrons, and protons

fatty acids are obtained from ___ in the diet and can be used to build ___

fats; phospholipids

the emergence of antibiotics in the early 1900s helped doctors treat which of the following diseases?

gonorrhea, meningitis, syphilis, and pneumonia

which of the following is an appropriate scientific question that could be investigated using the virtual experiment presented in this module?

how does color affect heat absorption?

one of the symptoms of rabies is fear and avoidance of water. this symptom can be described as a ___ behavior.

hydrophobic

a doctor has placed a human tissue sample in a test tube containing a solution. after a few minutes, the doctor returns to find that the tissue has shrunk and now appears "shriveled". the solution into which the tissue sample was placed is ___

hypertonic

in an experiment, the only difference between the control group and the experimental group is the ___ variable

independent

the nuclear envelope differs from the cell membrane and the membranous endoplasmic reticulum because it ___

is a double membrane

in the process of catabolism, a substrate ___

is broken into its products

a researcher is setting up a randomized clinical trial to evaluate the effect of acetaminophen on liver function, and designates a control group of subjects and an experimental group of subjects. what could interfere with the results or competition of this study?

members of the experimental group failing to take acetaminophen according to the experimental regimen

the term ___ refers to the chemical reactions that occur in the cell of a living organism.

metabolism

the organelle(s) in eukaryotic cells that contain(s) DNA is (are) the

mitochondria and nucleus

penicillin is isolated from ___

mold

which statement is NOT true with respect to facilitated diffusion?

movement of solute is from lower to higher concentration

an epidemiologist looks at a compilation of studies done at a medical center in which they have catalogued the lifestyle and habits of thousands in this group who have contracted breast cancer versus those who are healthy, she finds that woman who have breast cancer drink more milk than those who do not have cancer. does this mean that drinking milk causes breast cancer?

no; just because a correlation exists does not mean that milk is the cause of cancer

a study drew some conclusions about the health benefits of drinking coffee. would the same health benefits be expected for people who drink caffeinated tea?

not necessarily; coffee and tea contain many different compounds, and it could depend on the study population

a molecule with a carbon-based backbone and at least one C-H bond is a(n)

organic molecule

a student has placed rabbit cells in a solution containing dissolved oxygen, glucose, calcium ions, water, and sodium ions. which of these molecules do you expect will easily enter the students rabbit cell (via simple diffusion)?

oxygen

you create an artificial membrane that contains phospholipids but not proteins. which substance will be able to cross that membrane and in which direction?

oxygen from the side with the higher concentration to the side with the lower concentration

a researcher has submitted a paper assessing the relationship between ibuprofen and ulcers. much to his dismay, the journal responds to his paper by stating that- based on the comments of reviewers- it does not feel that it can publish the manuscript. the researchers paper has been rejected as a result of the ___ process

peer review

scientific results present in papers published in respected scientific journals have been ___

peer reviewed

scientists at at pharmaceutical company are exposing bacteria to new "prototype" antibiotics. during antibiotic treatment, many of these bacteria swell and eventually lyse. these new antibiotics likely target which of the following in bacteria?

peptidoglycan and synthesis and cell walls

a scientist is looking at a cell's membrane. she notices that the membrane is composed (primarily) of a certain type of macromolecule. these macromolecules are unique in that they are not composed of monomers, but instead resemble "hairpins" with fatty acid tails. this scientist is looking at ___

phospholipids

because water is ___, it can dissolve ___

polar; ions and other electronically charged molecules

a scientist has discovered a new macromolecule in mice. he determines that this macromolecule contains a unique combination of 20 distinct monomers, folds into an intricate three-dimensional shape, and is involved in a distinct chemical reaction. this scientist has likely discovered a ___

protein

an organic molecule made up of linked amino acid subunits is a(n)

proteins

which of these can assist in the transport of molecules across a membrane?

proteins

a scientist should communicate his or her results by ___ in order to have them carry the most weight.

publishing them in a peer-reviewed journal

which functional trait of a living organism is a mule NOT capable of?

reproduction

in eukaryotic cell lipids are produced in the ___

smooth ER

what is the complex carbohydrate used for energy in plant cells (but is not a good source of essential nutrients for humans)?

starch

which of these would NOT be considered a monomer?

sterols

which statement concerning cells is incorrect?

the average human cell is about 100 times smaller than the smallest bacterium

one way a vitamin can act as a coenzyme is to bind to ___

the enzyme and change its shape, so that it can bind to a substrate

if phospholipid-like molecules in an alien species had charged tails and uncharged heads, how would these molecules be arranged in alien cell membranes, assuming that the cells and their surroundings are aqueous in the aliens?

the heads would be heads facing in, and the tails would be facing out

homeostasis is ___

the maintenance of a relatively stable environment

all of these statements are true about enzymes EXCEPT...

they increase the activation energy

an infectious agent made up of a protein shell that encloses genetic information is a ___

virus

a researcher is culturing mouse cells in the laboratory. when he treats the cells with four vitamins- W, X, Y and Z- these cells survive and grow; he knows that some of these vitamins are essential nutrients. however, when he treats cells by removing one vitamin at a time, he gets the following results:vitamin W, cells live; vitamin X, cells live; vitamin Y, cells die; vitamin Z, cells die. based on these results, which of the following vitamins are likely essential nutrients?

vitamins Y and Z

osmosis is the movement of ___ into solutions with ___ concentrations of solutes

water; higher

what is the result of weight-bearing exercise on bone mass?

weight-bearing exercise cause the body to deposit calcium and phosphorus in bones

do you think that a mutation in an enzyme that changes its active site would change the function of the enzyme?

yes, because the active site binds specifically to the substrate to carry out the reaction

your doctor tells you that you have a mutation in the enzyme that breaks down complex carbohydrates. that enzyme does not work anymore. what might be the result?

you will be able to digest table sugar but not rice.