Consists of a single strand of nucleotides
RNA
is the genetic material that provides a blueprint for the organization, development, and function of living things.
DNA
The secondary structure of proteins can be____________ and ____________.
alpha helix and beta pleated sheets
The following structures are found in all eukaryotic cells EXCEPT
a. cell walls.
b. the nucleus.
c. plasma membranes.
d. Golgi bodies.
e. the endoplasmic reticulum.
Cell walls
Which of the following organelles is thought to have evolved from a bacterium?
a. nuclei
b. Golgi bodies
c. chloroplasts
d. mitochondriae.
c and d
Which of the following contain enzymes and are the main organelles of waste disposal?
a. Golgi bodies
b. mitochondria
c .lysosomes
d. ribosomes
e. endoplasmic reticulum
C. lysosomes.
Which of the following is found in BOTH plant and animal cells?
a. nucleus, Golgi body, and chloroplasts
b. Golgi bodies, mitochondria, and endoplasmic reticula
c. centrioles, cell wall, and nucleolus
d. vacuoles, nucleolus, and lysosomes
e. starch grains, chloroplasts, and lysosomes
b.
Which of the following is the correct difference between rough endoplasmic reticula and smooth ER?
a. rough ER is an extension of the nuclear envelope; smooth ER is not
b. smooth ER has a double bilayer membrane; rough ER does not
c. smooth ER consists of flattened sacs and tubes; rough ER does not
d. rough ER has a surface studded with ribosomes; smooth ER does not
e. smooth ER synthesizes proteins: rough ER does not
d. rough ER has a surface studded with ribosomes; smooth ER does not
No prokaryotic cells have
a. ribosomes.
b. a nucleus.
c. cytoplasm.
d. a plasma membrane.
e. cell walls.
b. a nucleus
Which of the following statements is CORRECT about the nature of enzymes?
a. All enzymes are proteins.
b. Most enzymes are RNAs.
c. Some enzymes are carbohydrates.
d. Most enzymes are proteins, but some are RNAs.
e. Most enzymes are proteins, but some are carbohydrates.
d. Most enzymes are proteins, but some are RNAs.
Which of the following statements is CORRECT about enzymes?
a. Most enzymes are proteins.
b. Enzymes speed up reactions that are intended to happen anyway.
c. Enzymes do not change the output of a reaction.
d. Enzymes can perform over and over.
e. All of these are correct.
E. All of these are correct.
An enzyme’s specificity is based on
a. the shape of its active site.
b. the amount of activation energy it requires.
c. the number of amino acids in its structure.
d. the nature of its cofactors.
e. none of these.
a. the shape of its active site.
What happens in an electron transport chain?
a. Electrons move from a low energy level to a higher energy level.
b. Electron movement generates energy which can be harvested.
c. Electrons combine with hydrogen ions to generate electron carriers, like NADH.
d. Energy is consumed.
e. The energy generated is used to break down coenzymes like NADH and ATP.
b. Electron movement generates energy which can be harvested.
If a single-celled freshwater organism is transferred to saltwater, which of the following is likely to happen?
a. The cell bursts.
b. The cell shrinks.
c. Salt is pumped out of the cell.
d. Enzymes flow out of the cell.
e.There is no effect.
b. The cell shrinks.
Unlike plants, fungi, and bacteria, animal cells cannot resist volume increases in hypotonic environments. This is because unlike those other organisms, animal cells
a. do not have central vacuoles.
b. do not have cell walls.
c. do not have pumps that can actively pump out excess fluid.
d. are smaller than those other cells and thus cannot handle large increases in volume.
e. have relatively more solutes.
b. do not have cell walls.
Oxygen, carbon dioxide, as well as other small molecules, cross the plasma membrane through the process(es) of
a. diffusion.
b. osmosis.
c. endocytosis and exocytosis.
d. active transport.
e. facilitated diffusion.
b. osmosis.
Which of the following statements about blood cells in solutions is CORRECT?
a. A blood cell placed in an isotonic solution will swell.
b. A blood cell placed in a hypotonic solution will swell.
c. A blood cell placed in a hypotonic solution will shrink.
d. A blood cell placed in an isotonic solution will shrink.
e. A cell placed in a hypotonic solution will remain the same size.
b. A blood cell placed in a hypotonic solution will swell.
Which of the following statements is CORRECT?
a. A solvent will diffuse from a hypotonic solution to a hypertonic solution.
b. A solvent will diffuse from a hypertonic solution to a hypotonic solution.
c. The concentration of the solute is greater in a hypotonic solution than in a hypertonic solution.
d. A solvent will experience net flow between two isotonic solutions.
e. Osmosis only occurs when both solutions separated by a membrane are hypertonic.
A solvent will diffuse from a hypotonic solution to a hypertonic solution.
The net direction that an ion or molecule moves is
a. dependent upon the size of the molecule.
b. unpredictable because the movement is random.
c. the result of concentration differences.
d.controlled by the temperature of the medium.
e. controlled by the membranes in the vicinity.
c. the result of concentration differences.
A solute passively diffuses through a transport protein out of the cell. What is the tonicity of the fluid inside the cell?
a. hypertonic
b. hypotonic
c. isotonic
d. none of these
e. more than one of these Classification.
Answer: a. hypertonic
This process is used by single celled amoeba to ingest and digest bacteria
e. phagocytosis
This process specifically moves water molecules across a differential permeable membrane.
c. osmosis
This process explains movement from areas of higher concentration to areas of lower concentration without the use of supplied energy.
simple diffusion
The process by which a lysosome expels its contents into the extracellular environment.
exocytosis
This process explains the movement of molecules against their concentration gradient.
active transport