Combo with AP Bio. and 2 others

the approximate molarity of the solution in which the mass of the plant pieces would not change is

0.3 M

The mechanism of action of many common medications involves interfering with the normal pathways that cells use to respond to hormone signals. Which of the following best describes a drug interaction that directly interferes with a signal transduction pathway?

A medication enters the target cell and inhibits an enzyme that normally synthesizes a second messenger.

The endocrine system incorporates feedback mechanisms that maintain homeostasis. Which of the following demonstrates negative feedback by the endocrine system?

After a meal, blood glucose levels become elevated, stimulating beta cells of the pancreas to release insulin into the blood. Excess glucose is then converted to glycogen in the liver, reducing blood glucose levels.

antobodies are made by

B cells

which of the follwing is the correct sequence of events in an action potential after stimulation of a neuron?

Na+ moves in; K+ moves out

A human kidney filters about 200 liters of blood each day. Approximately two liters of liquid and nutrient waste are excreted as urine. The remaining fluid and dissolved substances are reabsorbed and continue to circulate throughout the body. Antidiuretic hormone (ADH) is secreted in response to reduced plasma volume. ADH targets the collecting ducts in the kidney, stimulating the insertion of aquaporins into their plasma membranes and an increased reabsorption of water.If ADH secretion is inhibited, which of the following would initially result?

The person would produce greater amounts of dilute urine.

a nucleotide in DNA is made up of

a base plus a deoxyribose sugar plus phosphate

in general, a cell signaling causes

a change in a receptor protein conformation

which of the following is best observed by using a compound light micrscope?

a eukaryotic cell

what kind of cell does the macrophage activate in the humoral immune response?

a helper T cell

which of the following gland produces epinephrine

adrenal

the advantage of a controlled experiment is that

all variables are held constant except for one

which of the following pairs of functional groups characterizes the structure of an amino acid?

amine and carboxilid acid

which functional group is most likely responsible for an organic molecule behaving as a base?

amino

which of the following is correct concerning a spherical cell?

as the diameter decreases the surface to volume ratio increases

calls that contain only circular chromosomes are probably which of the following?

bacterial cells

the control of breathing is centered in which of the following areas of the brain?

brain stem

A pathogenic bacterium has been engulfed by a phagocytic cell as part of the nonspecific (innate) immune response. Which of the following illustrations best represents the response?

c

a molecule with the formaula C16,H30,O15 is a

carbohydrate

includes glycogens, chitin cellulose, and glucose

carbohydrates

most nerve cells communicate with other cells by means of

chemical signals that pass across synapses

which of the following would likely not be observed in a person injected with epinephrine

decreased activity of heart muscles

simple diffusion and facilitated diffusion are related in that both

depend on concentration gradient

for a covalent bond to be polar, the two atoms that form the bond must have

different electronegativities

which of the following best characterizes the reaction respresented by A+B+energy----> AB

endergonic reaction

When a substance moves across the plasma membrane along a concentration gradient at a rate faster than would be expected by simple diffusion alone but without the expenditure of metabolic energy, the process is best described as

facilitated diffusion

which of the following is least likely to result in a release of epinepherin (adrenaline) from the adrenal glands?

falling asleep during a lecture

compotitive inhibitors of enzymes work by

fitting in to the active sites

which of the following does not occur during inflammation and would healing?

histamines cause capillaries to constrict and reduce blood flow to the area

which of the following is responsible for the adhesive property of water?

hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule

if a person has an over active thyroid, you would expect them to have

increased metabolic rates in most tissues compared with a person who has typical thyroid function

the tertiary structure of a protein is determined by its

interactions among R groups

a reaction that has a negative delta G

is spontaneous

Which of the following is most directly responsible for water's unique properties?

it forms hydrogen bonds

a student using alight microscope observes a cell and correctly decided that it is a plant cell because

it has a large central vacuole

if instead of the bag a potato slice were placed in a beaker of distilled water which of the following would be true of the potato slice?

it would gain mass

used for insulation and bouyancy in marine animals

lipids

lipids form barriers surrounding various compartments within an organism. which property of lipids makes them a good barrier?

many biologically important molecules and ions are not soluble in liquids

he activation of the secondary immune response begins with which of the follwing?

memory cells

membranes are components of all the following except a

microtubule

the building blocks of carbohydrates are _____, and are covalantly linked together by _____.

monosaccharides, glycosidic linkages

if the potato solution was boiled for 10 minutes and cooled for 10 minutes befor being tested, the average time for the disks to float to the surface of the hydrogen peroxide solution would be

more than thirty seconds

the two primary cell types of the nervous system are

neurons and glia cells

used to carry the genetic code

nucleic acids

water enters and leaves the plant cells primarily by

osmosis

all of the following are typical components of the plasma membrane of a eukaryotic cell except

pigments

which of the following experimental designs should the students use as a control for the experiment

place a catalase soaked disk in a beaker of water

a prokaryotic cell has which of teh following

plasma membrane

which of the following components of the cell membrane is responsible for active transport

protein

synthesize at the ribose

proteins

to respond to a signal, a cell must have a ____ molecule that can detect the signal.

receptor

prokaryotic and eukaryotic cells generally have which of the following features in common?

ribosomes

which of the following statements about specific and nonspecific defenses is false?

specific defenses are typically the body's first line of defense

the main purpose of any single experiment is to

test a prediction that is based on a hypothesis

a controlled experiment is one that

test experimental and control groups in parallel

for a hypothesis to be scientifically valid, it must be ______ and it must be possible to ___ it.

testable;reject

which of the following best describes the condition expected afeter 24 hours?

the bag will contain more water than it did in the original condition

at equilibrium when the neuron is at rest

the concentration of K+ ions is higher inside the cell

which of the following organelles modifies the packages for secretion the materials produced by the ribosomes?

the golgi apparatus

which of the following best describes why the disks rose to the surfaces faster in the more concentrated hydrogen peroxide solutions

the higher substrate concentrations i the more concentrated solutions speeded the reactions

the ability of an atom to combine with other atoms is determined by

the number and distribution of electrons

the depolorization phase of an action potential is due to

the opening of valtage-gated sodium channels

enzymes that break down DNA catalyze the hydrolisis of the covalent bonds that join nucleotides together. What woukd happen to DNA molecules treated with these enzymes?

the phosphodiester linkages of the polynucleotide backbone would be broken

from the initial condidtions and the results described, which of the following is a logical conclusion?

the pores of the bag are larger than the glucose molecules but smaller than the starch molecules

which of the following would happen to an individual playing a long game of basketball outdoors on a hot afternoon?

the secretion of antidiuretic hormone from the pituitary gland would increase

which of the following best describes why ice was used during this experiment?

the slow the breakdown of the catalase

which of the following occurs in the tissue that is placed in 0.6 M sucrose?

the volume of the vacuoles decreases

all of the following statements about neurotransmitters are true except?

they are actively transported across the synaptic cleft

which of the following statements concerning unsaturated fats is true?

they have double bonds in the carbon chains o there fatty acids

the function of cellulose, the most abundant organic compound on earth is,

to provide mechanical strength to plant cell walls

the synthesis of protein or carbohydrate polymers always produces which of the following as a byproduct?

water