Which of the following choices correctly matches a tool and its proper application?
1 cell fractionation to study the function of specific organelles
2 transmission electron microscopy (TEM) to study the movement of organelles within a living cell
3 transmission electron microscopy (TEM) to study the surfaces of preserved cells
4 light microscopy to study the internal structure of cilia
5 scanning electron microscopy (SEM) to study the detailed movements of living cells
Which of the following clues would tell you if a cell is prokaryotic or eukaryotic?
whether or not the cell is partitioned by internal membranes
Which of the following correctly matches an organelle with its function?
1 mitochondrion ... photosynthesis
2 central vacuole ... storage
3 nucleus ... cellular respiration
4 lysosome ... movement
5 ribosome ... manufacture of lipids
In eukaryotic cells the first step in protein synthesis is the _____.
transferring of information from DNA to messenger RNA
Which of the following statements about the nuclear envelope is false?
1 The nuclear envelope is composed of two lipid bilayers.
2 The nuclear envelope is continuous with the Golgi apparatus.
3 Nuclear pores are made up of a group of proteins that are collectively called the nuclear pore complex.
4 Molecules pass into and out of the nucleus through nuclear pores.
True or false? Large proteins containing a nuclear localization signal (NLS) bind to the nuclear pore and enter the nucleus without any expenditure of energy.
A small protein (molecular weight = 25,000 daltons) is injected into a cell and observed in the nucleus a short time later. What type of transport has taken place?
In experiments to test whether a protein can enter the nucleus, why would proteins be labeled with fluorescent molecules?
make proteins easy to see
Which statement correctly describes the nuclear envelope of a eukaryotic cell?
1 The nuclear envelope is a single membrane, consisting of a phospholipid bilayer.
2 Plasmadesmosomes in the nuclear envelope permit the exchange of macromolecules between the nucleus and the cytoplasm.
3 All of the proteins of the cell are synthesized on ribosomes bound on the nuclear envelope.
4 The nuclear envelope is continuous with the endoplasmic reticulum.
5 The outer layer of the nuclear envelope is coated with laminin.
Which one of the following statements about the endomembrane system is correct?
1 Most of the phospholipids of the endomembrane system are synthesized in the mitochondria.
2 The endoplasmic reticulum is continuous with the plasma membrane.
3 Mitochondria function in the modification and sorting of lipids and proteins.
4 Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system.
5 Ribosomes move lipids and proteins among the different organelles of the endomembrane system.
A cell has formed a food vacuole as it ingested a food particle. Which of the following events is associated with the breakdown of that food particle?
1 The membrane of the food vacuole is derived from the cell wall.
2 Proteins for digestion of the food particle were initially processed in mitochondria.
3 Proteins for digestion of the food are made by ribosomes in the Golgi apparatus.
4 Enzymes for the breakdown of the food are delivered to the food vacuole from the cytosol.
5 Digestion of the food particle occurs in a vesicle enclosed by a membrane that separates the digestion from the cytoplasm.
Which of the following are common traits of chloroplasts and mitochondria?
1 Both reproduce by meiosis.
2 Both have their own DNA.
3 Both are surrounded by a single membrane.
4 Both are found in plant and animal cells.
5 Proteins for both are synthesized on ribosomes in the rough ER.
Which of the following functions is NOT associated with the cytoskeleton in eukaryotic cells?
1 maintaining the position of the nucleus in the cell
2 determining the shape of animal cells
3 the beating of cilia or flagella
4 the contraction of muscle cells in animals
5 Movement of RNA molecules from the nucleus to the cytoplasm
Which statement about extracellular structures (plant cell walls and the extracellular matrix of animal cells) is correct?
1 Information can be transmitted from these extracellular structures to the cytoplasm.
2 All extracellular structures form barriers to separate adjacent cells.
3 Extracellular structures store energy in the form of polysaccharides for subsequent metabolism by the cell.
4 Proteins and lipids are common components of extracellular structures.
5 Extracellular structures regulate the passage of water molecules across the cell membrane.
Identify the correct statement about differences between rough and smooth endoplasmic reticulum (ER).
1 Rough ER consists of a network of membranous tubules and sacs called cisternae, whereas smooth ER is less complex.
2 Smooth ER is part of the endomembrane system of the eukaryotic cell, and rough ER is not.
3 The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes.
Select the correct statement describing cellular structure or function.
1 Mitochondria and chloroplasts are part of the endomembrane system of the eukaryotic cell.
2 Only plant cells contain chloroplasts, and only animal cells contain mitochondria.
3 Plant and animal cells both carry out aerobic respiration, producing ATP.
Which of the following is not attached to the central carbon atom in an amino acid?
1 An amino functional group
2 A carboxyl functional group
3 An oxygen
4 A side chain ("R group")
Which of the following statements about the formation of polypeptides from amino acids is true?
1. A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.
2 The reaction occurs through the addition of a water molecule to the amino acids.
3 A bond can form between any carbon and nitrogen atom in the two amino acids being joined.
4 Polypeptides form by condensation or hydrolysis reactions.
A dehydration reaction (or condensation reaction) is the process in which _____.
water molecules are produced as a polymer is formed from monomers
The four main categories of large biological molecules present in living systems are _____.
proteins, nucleic acids, polysaccharides, and lipids
Which of the following statements about monosaccharide structure is true?
1 A six-carbon sugar is called a pentose.
2 Aldoses and ketoses differ in the position of their hydroxyl groups.
3 Monosaccharides can be classified according to the spatial arrangement of their atoms.
4 All monosaccharides contain carbon, hydrogen, oxygen, and nitrogen atoms.
Which of the following complex carbohydrates is listed with its correct function?
1 Amylose: main component of plant starch
2 Cellulose: structural component of plant cell walls
3 Chitin: constituent of bacterial cell walls
4 Starch: primary energy-storage molecule in animals
A function of cholesterol that does not harm health is its role _____.
as a component of animal cell membranes
Some regions of a polypeptide may coil or fold back on themselves. This is called _____, and the coils or folds are held in place by _____.
secondary structure ... hydrogen bonds
A hydrophobic amino acid R group (side group) would be found where in a protein?
on the inside of the folded chain, away from water
If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand?
If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?
The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases.
A nucleotide is composed of a(n) _____.
phosphate group, a nitrogen-containing base, and a five-carbon sugar
Which of the following statements about nucleotide structure is false?
1 The sugar is bonded to the phosphate group.
2 The sugar can be either ribose or deoxyribose.
3 The nitrogenous base is bonded to the sugar.
4 The phosphate group is bonded to the nitrogenous base.
Which of the following statements about DNA structure is true?
1 Phosphodiester bonds form between the phosphate group of one nucleotide and the 5' carbon of the adjacent nucleotide.
2 The nucleic acid strands in a DNA molecule are oriented antiparallel to each other.
3 DNA is always synthesized in the 3' to 5' direction.
4 The arrangement of the sugar-phosphate groups determines the genetic code.
Which feature of large biological molecules explains their great diversity?
The many ways that monomers of each class of biological molecule can be combined into polymers