Discovering Life's Fundamental Unit: What Stands as the Smallest?

The smallest unit capable of life by itself is (a) the organ, (b) the organelle, (c) the tissue, (d) the cell, (e) the nucleus.

The major types of lipid found in the plasma membranes are (choose two) (a) cholesterol, (b) triglycerides, (c) phospholipids, (d) fat-soluble vitamins.

Membrane junctions that allow nutrients or ions to flow from cell to cell are (a) desmosomes, (b) gap junctions, (c) tight junctions, (d) all of these.

The term used to describe the type of solution in which cells will lose water to their environment is (a) isotonic, (b) hypertonic, (c) hypotonic, (d) catatonic.

Osmosis always involves (a) a selectively permeable membrane, (b) a difference in solvent concentration, (c) diffusion, (d) active transport, (e) a, b, and c.

A physiologist observes that the concentration of sodium inside a cell is decidedly lower than that outside the cell. Sodium diffuses easily across the plasma membrane of such cells when they are dead, but not when they are alive. What cellular function that is lacking in dead cells explains the difference? (a) osmosis, (b) diffusion, (c) active transport (solute pumping), (d) dialysis.

The solute-pumping type of active transport is accomplished by (a) exocytosis, (b) phagocytosis, (c) electrical forces in the cell membrane, (d) changes in shape and position of carrier molecules in the plasma membrane.

The endocytotic process in which a sampling of particulate matter is engulfed and brought into the cell is called (a) phagocytosis, (b) pinocytosis, (c) exocytosis.

Which is not true of centrioles? (a) They start to duplicate in G1, (b) they lie in the centrosome, (c) they are made of microtubules, (d) they are membrane-walled barrels lying parallel to each other.

The nuclear substance composed of histone proteins and DNA is (a) chromatin, (b) the nucleolus, (c) nuclear sap, or nucleoplasm, (d) nuclear pores.

The information sequence that determines the nature of a protein is the (a) nucleotide, (b) gene, (c) triplet, (d) codon.

Mutations may be caused by (a) X rays, (b) certain chemicals, (c) radiation from ionizing radioisotopes, (d) all of these.

The phase of mitosis during which centrioles reach the poles and chromosomes attach to the spindle is (a) anaphase, (b) metaphase, (c) prophase, (d) telophase.

Final preparations for cell division are made during the life cycle subphase called (a) G1, (b) G2, (c) M, (d) S.

The RNA synthesized on one of the DNA strands is (a) mRNA, (b) tRNA, (c) rRNA, (d) all of these.

The RNA species that travels from the nucleus to the cytoplasm carrying the coded message specifying the sequence of amino acids in the protein to be made is (a) mRNA, (b) tRNA, (c) rRNA, (d) all of these.

If DNA has a sequence of AAA, then a segment of mRNA synthesized on it will have a sequence of (a) TTT, (b) UUU, (c) GGG, (d) CCC.

A nerve cell and a lymphocyte are presumed to differ in their (a) specialized structure, (b) suppressed genes and embryonic history, (c) genetic information, (d) a and b, (e) a and c.

A pancreas cell makes proteins (enzymes) that it releases to the small intestine. Which of the following best describes the path of these proteins from synthesis to exocytosis at the pancreatic cells plasma membrane (PM)? (a) Golgi S rough ER S PM, (b) smooth ER S Golgi S lysosome S PM, (c) rough ER S Golgi S PM, (d) nucleus S Golgi S PM.

Which organelle is responsible for a newborn having distinctive toes and fingers instead of webbed digits?

Explain why mitosis can be thought of as cellular immortality.

Contrast the roles of ER-bound ribosomes with those free in the cytosol.

Cells lining the trachea have whiplike motile extensions on their free surfaces. What are these extensions, what is their source, and what is their function?

Name the three phases of interphase and describe an activity unique to each phase.

Comment on the role of the sodium-potassium pump in maintaining a cells resting membrane potential.

Differentiate between primary and secondary active transport processes.

Cell division typically yields two daughter cells, each with one nucleus. How is the occasional binucleate condition of liver cells explained?