Biological membranes are composed primarily of a. nucleotides and nucleosides. b. enzymes, electron acceptors, and electron donors. c. fatty acids. d. monosaccharides. e. lipids.

Plant cells transport sucrose across the vacuole membrane against its concentration gradient by a process known as a. simple diffusion. b. active transport. c. passive transport. d. facilitated diffusion. e. cellular respiration.

Which organelle is generated by the Golgi apparatus and contains digestive enzymes to hydrolyze macromolecules? a. Glyoxysome b. Lysosome c. Peroxisome d. Phagosome e. Ribosome

Steroids such as cholesterol are synthesized by a. chloroplasts. b. lysosomes. c. the smooth ER. d. the Golgi apparatus. e. mitochondria

Plasma membranes are relatively impermeable to water-soluble molecules because a. the membranes are waxy. b. water molecules are nonpolar. c. their bilayer is comprised of phospholipids. d. they have salt crystals embedded within them. e. large proteins extend through both sides of the membranes.

If a cell lacked ribosomes, it would not be able to a. translate messenger RNA into DNA. b. make RNA from DNA. c. translate proteins into messenger RNA. d. transcribe DNA into mRNA. e. make proteins.

Which of the following represents is the correct arrangement of items in order of size, from smallest to largest? a. Lipid molecule; carbon atom; bacterium; virus; plant cell b. Bacterium; virus; carbon atom; lipid molecule; plant cell c. Carbon atom; lipid molecule; virus; bacterium; plant cell d. Plant cell; bacterium; virus; carbon atom; lipid molecule e. Carbon atom; lipid molecule; bacterium; virus; plant cell

Which type of membrane protein would likely be most easily removed in a laboratory experiment? a. Integral membrane proteins b. Channel proteins c. Peripheral membrane proteins d. Transmembrane proteins e. Gated channels

A student has built a model of a plant cell for a science fair. It consists of a balloon filled with water that is placed within a plastic bag that also contains water, and this bag is held within a plastic box. In this model, the balloon most likely represents a _______, the plastic bag represents the _______, and the plastic box represents the _______. a. chromosome; nucleus; cell membrane b. vacuole; cell membrane; cell wall c. chloroplast; nucleus; cell membrane d. thylakoid; chloroplast; cell wall e. nucleus; cytoplasm; cell membrane

Which of the following is/are found in prokaryotic cells? a. Mitochondria b. Chloroplasts c. Nuclear membrane d. Ribosomes e. Endoplasmic reticulum

. If a cell is making a protein that is then going to be modified and packaged for export out of the cell, what is the order of structures it will most likely pass through? a. Vesicle; smooth ER; Golgi apparatus b. Rough ER; Golgi apparatus; vesicle c. Golgi apparatus; rough ER; ribosome d. Rough ER; Golgi apparatus; lysosome e. Smooth ER; Golgi apparatus; vesicle

If a hospital patient is mistakenly given an IV of pure water instead of a saline solution that is isotonic to blood, the patient’s red blood cells will a. shrink and collapse. b. release water to the plasma along its concentration gradient. c. absorb water from the plasma and eventually burst. d. transport equal amounts of water across the cell membrane in both directions. e. work with white blood cells to maintain the water level in the plasma

A large organelle found in eukaryotic cells that genetically controls the cell’s activities is the a. chloroplast. b. nucleus. c. flagellum. d. vacuole. e. centriole.

The rough ER is the portion of the ER that a. lacks ribosomes. b. is the oldest and was once the smooth ER. c. has ribosomes attached to it. d. is connected to the Golgi apparatus. e. is the site of steroid synthesis.

A specialized structure found in most, but not all, prokaryotes is the a. cell wall. b. ribosome. c. cytosol. d. mitochondrion. e. chloroplast.

In biological membranes, the phospholipids are arranged in a _______, with the _______. a. bilayer; fatty acids pointing toward each other b. bilayer; fatty acids facing outward c. single layer; fatty acids facing the interior of the cell d. single layer; phosphorus-containing region facing the interior of the cell e. bilayer; phosphorus groups in the interior of the membrane

Which statement about cholesterol molecules is true? a. They help hold a membrane together. b. They alter the fluidity of the membrane. c. They attach to carbohydrates. d. They disrupt membrane function. e. They transport ions across membranes

Osmosis a. helps plant cells maintain turgor pressure. b. moves macromolecules from one cell to another. c. facilitates the “flipping” of proteins from one side of the membrane to the other. d. keeps concentrations uniform in all cells. e. causes cells to lose water when they are placed in a hypotonic solution.

If a drop of red ink is placed in one end of a shallow pan filled with water, and a drop of green ink is placed in the other end, which of the following will be true at equilibrium? a. The red ink will be uniformly distributed in one half of the pan, and the green ink will be uniformly distributed in the other half of the pan. b. The red and green inks will be uniformly distributed throughout the pan. c. Each ink will begin moving down its concentration gradient. d. The concentration of each ink will be higher at one end of the pan than at the other end. e. No predictions can be made without knowing the molecular weights of the pigment molecules.

A major distinction between prokaryotic and eukaryotic cells is that a. prokaryotic cells do not have a nucleus, whereas eukaryotic cells do. b. prokaryotic cells do not have DNA, whereas eukaryotic cells do. c. prokaryotic cells are larger than eukaryotic cells. d. prokaryotic cells have not prospered, whereas eukaryotic cells are evolutionary “successes.” e. prokaryotic cells cannot obtain energy from their environment, whereas eukaryotic cells can.

sunlight energy is used to make sugar.

Most cells are small because a. a reduced surface area-to-volume ratio increases metabolic rates within the cell. b. a larger surface area-to-volume ratio increases the efficiency of processes within the cell. c. small cells are able to live longer than large cells. d. small cells lose less heat to the environment than large cells. e. it is easier to package small cells within a cell wall.

Most of the cells in the human body (your blood cells, for example) are a. smaller than a mitochondrion, but larger than most molecules. b. smaller than small molecules, but larger than an atom. c. smaller than the period at the end of this sentence, but larger than most bacteria. d. about the size of the period at the end of this sentence. e. larger than the period at the end of this sentence, but smaller than the width of one of your hairs.

Which statement about diffusion is false? a. Diffusion does not require ATP. b. Diffusion continues until the molecular concentrations are in equilibrium. c. In diffusion, molecules move from areas of greater concentration to areas of lesser concentration. d. Diffusion is a random process. e. Simple diffusion depends upon specific carrier proteins.

Chloroplasts are structures in which a. chemical energy is stored in the form of ATP. b. cell division is controlled. c. genetic information is used to make proteins. d. sunlight energy is used to make sugar. e. new organelles are made.