Test 1 Review Questions

A key rate limiting step in heme synthesis is suppression of: a. aminolevulinate synthase b. carbonic anhydrase c. protoporphyrin IX reductase d. Glucose 6-phosphate dehydrogenase

A

After focusing a specimen by using the 40x objective, the lab professional switches to a 10x objective. The specimen remains in focus at 10x. Microscopes with this characteristic are described as: a. parfocal b. par centric c. compensated d. parachromatic

A

Normal adult Hb A contains which polypeptide chains? a. alpha and beta b. alpha and delta c. alpha and gamma d. alpha and epsilon

A

The recommended cleaner for removing oil from objectives is: a. 70% alcohol or lens cleaner b. xylene c. water d. benzene

A

Using the normal hemoglobin-oxygen dissociation curve in Figure 10-7 for reference, predict the position of the curve when there is a decrease in pH. a. shifted to the right of normal with decreased oxygen affinity b. shifted to the left of normal with increased oxygen affinity c. shifted to the right of normal with increased oxygen affinity d. shifted to the left of normal with decreased oxygen affinity

A

Where should alcohol and other flammable chemical be stored? a. in an approved safety can or storage cabinet away from heat sources b. under a hood and arranged alphabetically for ease of identification in an emergency c. in a refrigerator at 2C to 8C to reduce volatilization d. on a low shelf in an area protected from light

A

Which of the following forms of hemoglobin molecule has the lowest affinity for oxygen? a. tense b. relaxed

A

According to OSHA standards, lab coats must be all of the following except: a. water resistant b. made of cloth fabric that can be readily laundered c. long-sleeved d. worn fully buttoned

B

Dark field microscopes create the dark field by: a. using two filters that dance leach other out, one above and the other below the condenser b. angling the light at the specimen so that it misses the objective unless something in the specimen bend sit backward c. closing the condenser diaphragm entirely, limiting light to just a tiny ray in the center of the otherwise dark field d. using a light source above the specimen and collecting light reflected from the specimen, rather than transmitted through the specimen, so that when there is no specimen, the field is dark

B

How are the globin chain genes arranged? a. with alpha genes and beta genes on the same chromosome, including two alpha genes and two beta genes b. with alpha and beta genes on separate chromosomes, including two alpha genes on one chromosome and one beta gene on a different chromosome c. with alpha genes and beta genes on the same chromosome, including four alpha genes and four beta genes d. with alpha and beta genes on separate chromosomes, including four alpha genes on one chromosome and two beta genes on a different chromosome

B

It is a busy evening in the City Hospital hematology department. One staff member called in sick, and there was a major auto accident that has one staff member tied up in the blood bank all evening. Mary, the medical lab scientist covering hematology, is in a hurry to get a stat sample of the analyzer but needs to pour off an aliquot for another department. She is wearing gloves and a lab coat. She carefully covers the stopper of the well mixed EDTA tube with a gauze square and tilts the stopper toward her so it opens away from her. She pours off about 1 mL into a relabeled tube, replaces the stopper of the EDTA tube, and puts it in the sample rack and sets it on the conveyor. She then brings the poured sample off to the other department. How would you assess Mary's safety practice? a. Mary was careful and followed all appropriate procedures b. Mary should have used a shield when opening the tube c. Mary should have poured the sample into a sterile tube d. Mary should have wiped the tube with alcohol after replacing the stopper

B

The most frequent cause of needle punctures is: a. patient movement during venipuncture b. improper disposal of phlebotomy equipment c. inattention during removal of needle after venipuncture d. failure to attach needle firmly to syringe or tube holder

B

The most important practice in preventing the spread of disease is: a. wearing masks during patient contact b. proper hand washing c. wearing disposable laboratory coats d. identifying specimens from known or suspected HIV- and HBV-infected patients with a red label

B

Use of which one of the following type of objective lens causes the center of the microscope field to be in focus, whereas the periphery is blurred? a. plan achromatic b. achromatic c. plan apochromatic d. flat field

B

What class fire extinguisher would be appropriate to used on a fire in a chemical cabinet> a. class a b. class b c. class c d. class d

B

Which objective has the greatest degree of color correction? a. achromatic b. plan apochromatic c. dichromatic d. plan achromatic

B

Which of the following is a description of the structure of oxidized hemoglobin? a. hemoglobin carrying oxygen on heme; synonymous with oxygenated Hgb b. Hgb with iron in the ferric state (methemoglobin) and not able to carry oxygen c. Hgb with iron in the ferric state so that co2 replaces o2 in the heme structure d. Hgb carrying co; hence "oxidized" refers to the single oxygen

B

How frequently should fire alarms and sprinkler systems be tested? a. weekly b. monthly c. quarterly d. annually

C

In adjusting the microscope light using Koehler illumination, which one of the following is true? a. condenser is first adjusted to its lowest position b. height of the condenser is adjusted by removing the eyepiece c. image of the field diaphragm iris is used to center the condenser d. closing the aperture diaphragm increases the resolution of the image

C

The appropriate dilution of bleach to be used in laboratory disinfection is: a. 1:2 b. 1:5 c. 1:10 d. 1:100

C

The nature of the interaction between 2,3 BPG and Hgb is that 2,3 BPG: a. binds to the heme moiety, blocking the binding of o2 b. binds simultaneously with o2 to ensure that it stays bound until it reaches the tissues, when both molecules are released from Hgb c. binds to AA's of the globin chain, contributing to a conformational change that inhibits o2 from binding to heme d. oxidizes Hgb iron, diminishing o2 binding and promoting o2 delivery to the tissues

C

The total magnification obtained when a 10x eyepiece and a 10x objective lens are used is: a. 1x b. 10x c. 100x d. 1000x

C

Under which of the following circumstances would a SDS he helpful? a. a phlebotomist has experienced a needle puncture with a clean needle b. a fire extinguisher failed during routine testing c. a pregnant lab employee has asked whether she needs to be concerned about working with a given reagent d. during a safety inspection, an aged microscope power supply is found to have a frayed power cord

C

What is the normal distribution of hemoglobins in healthy adults? a. 80% to 90% Hb A, 5%-10% Hb A2, 1-5% Hb F b. 80-90% Hb A2, 5-10% Hb A, 1-5% Hb F c. >95% Hb A, <3.5% Hb A2, 1-2% Hb F d. >90% Hb A, 5% Hb F, <5% Hb A2

C

Which of the following gathers, organizes, and directs light through the specimen? a. eyepiece b. objective lens c. condenser d. optical tube

C

Which of the following types of microscopy is valuable in the identification of crystals that are double refractive? a. compound brightfieqld b. dark field c. polarizing d. phase-contrast

C

A hemoglobin molecule is composed of: a. one heme molecule and four globin chains b. ferrous iron, proporphyrin IX, and a globin chain c. protoporphyrin IX and four globin chains d. four heme molecules and four globin chains

D

A lab science student has been reviewing a hematology slid using the 10x objective to find a suitable portion of the slide for examination. He moves the 10x objective out of place, places a drop of oil on the slide, rotates the nosepiece so that the 40x objective passes through the viewing position, and continues to rotate the 100x oil objective lens into viewing position. This practice should be corrected in which way? a. the stage of a par focal microscope should be lowered before the objectives are rotated b. the 100x oil objective should be inlace for viewing before the oil is added c. the drop of oil should be in place and the 100x objective lowered into the oil, rather than swinging the objective onto the drop d. the objectives should be rotated in the opposite direction so that the 40x objective does not risk entering the oil

D

After a microscope has been adjusted for Koehler illumination, and the specimen is being viewed with an oil immersion objective lens, light intensity should never be regulated by adjusting the: a. rheostat b. neutral density filter c. light control knob d. condenser

D

In the quaternary structure of hemoglobin, the globin chains associate into: a. alpha tetramers in some cells and beta tetramers in others b. a mixture of alpha tetramers and beta tetramers c. alpha dimers and beta dimers d. two alpha beta dimers

D

Standard precautions apply to all of the following except: a. blood b. cerebrospinal fluid c. semen d. concentrated acids

D

The predominant hemoglobin found in a healthy newborn is: a. gower-1 b. gower-2 c. A d. F

D

Which one of the following would NOT be part of a safety management plan? a. job safety analysis b. risk assessment of potential safety hazards c. mechanism for reporting accidents d. budget for engineering controls and personal protective equipment

D