Chapter 5: Genome Structure, Regulation, and Tissue Differentiation

Chapter 5: Genome Structure, Regulation, and Tissue Differentiation

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

MULTIPLE CHOICE
1. Approximately what percentage of the human DNA chromosomes code for proteins?
a. 1%
b. 10%
c. 50%
d. 80%
ANS: A
Only about 1.3% of chromosomal DNA codes for proteins.
REF: Pg. 75
2. Which tissue type is categorized as epithelial?
a. Tendons and ligaments
b. Blood cells
c. Blood vessel endothelium
d. Cartilage
ANS: C
Epithelial cells line glands, blood vessels, and internal surfaces. Tendons, ligaments, blood cells, and cartilage are connective tissue.
REF: Pg. 84
3. An important difference between skeletal and cardiac muscle is that
a. cardiac muscle is not striated.
b. only skeletal muscle is dependent upon actin-myosin cross-bridging.
c. calcium does not leave the sarcoplasmic reticulum in cardiac cells.
d. cardiac muscle has calcium channels on the cell surface for calcium entry.
ANS: D
Only cardiac muscle has calcium channels on the cell surface for calcium entry into the cell. Drugs called calcium channel blockers
are used to decrease calcium entry into cardiac cells to reduce contractile force in treating hypertension. CCBs also relax smooth
muscle in arterial blood vessels to treat hypertension. Both cardiac and skeletal muscle are striated, and both cardiac depend upon
actin-myosin cross-bridging for contraction. Calcium leaves the sarcoplasmic reticulum in both cardiac and skeletal muscle.
REF: Pg. 88
4. The primary role of genes is to
a. code for reproduction.
b. direct the synthesis of proteins.
c. determine differentiation.
d. determine cellular apoptosis.
ANS: B
Protein synthesis holds a predominant place in understanding how genes direct cell structure and function. Although genes are
involved in reproduction, differentiation, and apoptosis indirectly, the primary role of genes in the body is protein synthesis.
REF: Pg. 77
5. The differences in structure and function of cells in different body tissues is due to
a. gene differences in tissue cells.
b. expression of tissue-specific genes.
c. transcriptional controls.
d. translation of amino acids to proteins.
ANS: B
The expression of genes results in differences among cells, and thus tissue types. All cells in the body contain basically the same
genes. Expression of genes is influenced by memory of cells regarding events prior to cell division, not differences in gene
structure. As genes in all body cells/tissues is basically the same; transcription and translation do not influence cell/tissue
differences.