Textbook of Histology 4th Edition Gartner Test Bank
Gartner: Textbook of Histology, 4th Edition
Chapter 2 – Cytoplasm Test Bank
MULTIPLE CHOICE
- The fluidity of the plasmalemma has well-established clinical significance. Which of the
following molecules decreases the cell membrane fluidity?
- glycerol
- phosphate group
- cholesterol
- integral proteins
- peripheral proteins
Explanation:
The answer is c. Cholesterol decreases membrane fluidity. The polar heads of phospholipids molecules are composed of glycerol, to which a positively charged nitrogenous group is attached by a negatively charged phosphate group. Unsaturated fatty acyl molecules increase membrane fluidity. Integral aTndEpSeTriBphAeNraKl pSrEotLeiLnEs dRo.nCoOt hMave an effect on membrane fluidity.
- A patient suffering from asthma has difficulty breathing and is treated with albuterol, a drug
that relaxes bronchiolar smooth muscles. Albuterol acts as a(n)
- cholinergic receptor antagonist
- cholinergic receptor antagonist
- adrenergic receptor antagonist
- adrenergic receptor agonist
- inhibitor of kinase phosphorylases
Explanation:
The answer is d. Albuterol is an agonist that acts on β2-adrenergic receptors that are located mainly on the cell membranes of bronchial tissues and, therefore, do not have many side effects. If it were an antagonist, then it would cause smooth muscle constriction.
- A patient suffering from asthma has difficulty breathing and is treated with albuterol and
ipratropium, drugs that relax bronchiolar smooth muscles. Ipratropium acts as a(n)
- cholinergic receptor antagonist
- cholinergic receptor antagonist
- adrenergic receptor antagonist 1 / 4
Test Bank 2
- adrenergic receptor agonist
- inhibitor of kinase phosphorylases
Explanation:
The answer is a. Ipratropium is a cholinergic receptor antagonist and interferes with the binding of acetylcholine, a neurotransmitter, to its receptor sites on the cell membrane, thus preventing the contraction of bronchiolar smooth muscle. The two drugs are used in combination agonist-antagonist therapy to have the desired effect of maintaining an open airway.
- A 9-month-old female Jewish baby, whose parents were born in Poland, is seen by her
pediatrician because of neurologic problems, including generalized paralysis and blindness.The pediatrician should suspect that the child is suffering from
- spina bifida
- cranial nerve X (vagus nerve) disorder
- Tay-Sachs disease
- Fabry’s disease
- Refsum’s disease
Explanation:
The answer is c. Tay-Sachs disease affects mostly children of Eastern European Jewish ancestry as well as certain families in Lousiana of Cajun ancestry. Children suffering from this lysosomal-storage disease canTnEotScTatBaAboNliKzeSGEMLL2 EgaRn.glCioOsiMdes that accumulate in their lysosomes, and the enlarged lysosomes interfere with cell function. The interference is most problematic in the neurons of the central nervous system and causes death by the third year of life. Neither spina bifida nor vagus nerve disorders would cause generalized paralysis or blindness. Fabry’s disease, although a lysosomal-storage disorder, is due to an X chromosomal defect and affects only males. Refsum’s disease is due to the accumulation of phytanic acid, a by-product of chlorophyll metabolism, and affects older children who already eat fresh fruits and vegetables.
- Acid hydrolases are synthesized on the rough endoplasmic reticulum and are delivered to the
Golgi complex to be packaged and distributed to their final destination. In patients whose protooncogenes have mutated to form ras protein–related products known as ADP-ribosylation factor (ARF), this factor may interfere with
- coatomer II (COP II) synthesis
- coatomer II (COP II) assembly
- coatomer II (COP II) dissociation from vesicles
- clathrin synthesis
- clathrin assembly
Explanation:
The answer is b. Delivery of proteins manufactured on the rough endoplasmic reticulum to the Golgi complex is accomplished in COP-II coated vesicles. ARF catalyzes the assembly of 2 / 4
Test Bank 3 COP-II molecules to form coatomer on the cytoplasmic aspect of these transfer vesicles.Synthesis of COP-II proteins as well as the disassembly of the coatomer are not influenced by ARF. Clathrin coats mediate the endocytotic pathway as well as the pathway that leads away from the trans Golgi network.
- Patients with sickle cell anemia possess hemoglobin-s, a mutated form of hemoglobin.
Hemoglobin-s is
- synthesized on free ribosomes
- synthesized on the rough endoplasmic reticulum
- modified in the Golgi apparatus
- packaged in the trans Golgi network
- stored in condensing vesicles
Explanation:
The answer is a. Hemoglobin, whether normal or mutated, is present freely in the cytosol; therefore, it is synthesized on free ribosomes. Only proteins that are to be packaged are synthesized on the rough endoplasmic reticulum. Because hemoglobin is not packaged, it does not enter the Golgi apparatus.
- A neonatal baby boy is observed to have malformed hands, feet, and skull. Additional
examination displays jaundice, hepatomegaly, and hypotonic muscles with psychomotor retardation. The pediatrician diagnoses the disorder as cerebrohepatorenal syndrome (Zellweger’s syndrome). ThisTcEoSndTitBioAnNisKdSuEe LtoLpEroRb.leCmOsMwith which of the following organelles?
- mitochondria
- lysosomes
- early endosomes
- late endosomes
- peroxisomes
Explanation:
The answer is e. Children with cerebrohepatorenal syndrome die at an early age due to mutations in their peroxin genes that code for defective receptors that are unable to transfer enzymes destined for peroxisomes into these organelles. Mitochondria, lysosomes, and endosomes are not affected by this mutation.
- A 20-year-old male seeking help from his ophthalmologist presents with deteriorating vision
in both eyes, especially his central vision. The patient also evidences cardiac dysrythmia and an apparent demyelination of the optic nerve. The ophthalmologist suspects Leber’s hereditary optic neuropathy, a condition caused by a point mutation that is not X-linked but is transmitted only by females. This condition is due to problems with which of the following?
- lysosomes
- early endosomes 3 / 4
Test Bank 4
- late endosomes
- mitochondria
- peroxisomes
Explanation:
The answer is d. Leber’s hereditary optic neuropathy is due to a point mutation on the mitochondrial DNA. Because the spermatozoon does not contribute mitochondria to the zygote, only the female can transmit this condition to her offspring. Lysosomes, peroxisomes, and early and late endosomes do not possess DNA.
- Which of the following refers to cadherins?
- they are peripheral proteins
- they are associated with cell-cell adhesion
- they are associated with adherence to the basal lamina
- they have binding sites for heparin sulfate
- they are associated with hemidesmosomes
Explanation:
The answer is b. Cadherins are integral proteins that are designed to assist cells to maintain contact with one another. Hemidesmosomes, heparin sulfate, and basal lamina are all associated with cell-to-extracellular matrix contact.
- Dynein arms are always aTttEacSheTdBtAo NonKeSoEf LthLe EfoRll.owCiOnMg. Which one is that structure?
- central sheet
- singlets
- subunit A
- subunit B
- radial spoke
Explanation:
The answer is c. Dynein arms are microtubule-associated proteins that function in bending of the cilium. These molecular motors are attached to the subunit A of the axoneme. The central sheet and the radial spokes are both composed of an elastic protein that becomes stretched during the “cocking” of the axoneme and, as they return to their normal length, they effect ciliary motion.
- The component of the erythrocyte cell membrane that is the most essential in maintaining
its biconcave disc shape is
- glycophorin
- spectrin
- ankyrin
- actin
- band 3 protein
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