SCFHS Genomic & Biotechnology Technician exam questions

The Genomic & Biotechnology Technician exam in every GCC country

From each regulator's own exam pages; anything a regulator does not publish says so. Assessment mode also depends on your licence title, so confirm your route on your eligibility notice.

12 worked Genomic & Biotechnology Technician practice questions

Original exam-style questions from the bank, spread across the blueprint domains. They are not real or recalled exam questions. Try each one, then open the answer for the rationale and reference. None of them appear in the free mock exam, so reading them will not spoil it.

1. Question 1 · Basic Laboratory Skills

   A protocol states that cells must be spun at 12,000 x g, but the laboratory centrifuge shows only rpm and has a different rotor radius. What is the correct approach?

   1. AUse 12,000 rpm directly, since rpm and relative centrifugal force are the same unit
   2. BSpin at half the speed for twice the time to deliver the same total force
   3. CConvert using the rotor radius, since RCF depends on radius as well as speed
   4. DUse the maximum speed of the centrifuge so that the cells are pelleted fully
   Show answer and explanation

   Correct answer: C. Convert using the rotor radius, since RCF depends on radius as well as speed

   RCF is proportional to radius multiplied by the square of the rotational speed, so the same rpm gives different g with different rotors. g and rpm are not equal, halving speed changes the force by four, and maximum speed may damage samples.

   Reference: Green and Sambrook, Molecular Cloning: A Laboratory Manual, 4th ed., 2012

2. Question 2 · Bioinformatics

   What is the main difference between FASTA and FASTQ files?

   1. AFASTA includes quality scores for each base, but FASTQ does not hold them
   2. BFASTQ includes a quality score for each base, but FASTA does not
   3. CFASTQ holds protein sequences, while FASTA holds nucleotide sequences
   4. DFASTA is a compressed binary alignment file produced by the aligner
   Show answer and explanation

   Correct answer: B. FASTQ includes a quality score for each base, but FASTA does not

   FASTQ stores sequence plus per-base quality, while FASTA holds only sequence. Neither is restricted to proteins, and BAM, not FASTA, is the compressed alignment format.

   Reference: Cock et al., Nucleic Acids Research 2010;38:1767-1771

3. Question 3 · Bioinformatics

   A BLAST search returns two hits with E-values of 1e-50 and 0.5. How should they be interpreted?

   1. AThe second is more significant than the first because its value is larger
   2. BThe first is a far more significant match than the second one
   3. CBoth are equally significant because both values are below one
   4. DE-values above zero are treated as invalid and are discarded
   Show answer and explanation

   Correct answer: B. The first is a far more significant match than the second one

   A smaller E-value means fewer matches expected by chance, so 1e-50 is highly significant. An E-value of 0.5 is not significant, and other options misread the scale.

   Reference: Altschul et al., Journal of Molecular Biology 1990;215:403-410

4. Question 4 · Biotechnology

   In a bioreactor, a fed-batch process rather than a simple batch process is chosen. What is the main benefit?

   1. AThe vessel is emptied continuously so that cells and product do not accumulate inside it
   2. BFeeding is unnecessary after inoculation because the medium is complete
   3. CNutrients are added gradually, extending growth and limiting inhibitory by-products
   4. DOxygen demand is removed because cells grow more slowly in a nutrient-limited culture
   Show answer and explanation

   Correct answer: C. Nutrients are added gradually, extending growth and limiting inhibitory by-products

   Controlled feeding keeps substrate low and prolongs production. Continuous removal describes continuous culture, nutrients are still needed, and oxygen demand remains.

   Reference: Renneberg, Biotechnology for Beginners, 3rd ed.

5. Question 5 · Genomics

   A variant is found in about 48% of reads in both blood and saliva samples from a patient. What is the most likely interpretation?

   1. AA low-level somatic mosaic variant
   2. BA sequencing error in one strand
   3. CA homozygous constitutional variant
   4. DA heterozygous constitutional variant
   Show answer and explanation

   Correct answer: D. A heterozygous constitutional variant

   Close to half of reads in different tissues points to heterozygosity present in all cells. Mosaicism would give a lower fraction, and a homozygous variant would be near 100%.

   Reference: Richards et al., ACMG/AMP variant interpretation, Genetics in Medicine 2015;17:405-424

6. Question 6 · Molecular Techniques

   A standard curve for a real-time PCR assay has a slope of minus 3.6. What is the approximate amplification efficiency?

   1. AAbout 100%
   2. BAbout 90%
   3. CAbout 110%
   4. DAbout 70%
   Show answer and explanation

   Correct answer: B. About 90%

   Efficiency = 10^(-1/slope) - 1, which for minus 3.6 is about 0.90, or 90%. A slope near minus 3.32 gives 100%, and a slope shallower than that, near minus 3.1, gives over 100%.

   Reference: Bustin et al., The MIQE guidelines, Clinical Chemistry 2009;55:611-622

7. Question 7 · Molecular Techniques

   A DNA extract gives an A260/A280 ratio of 1.3 on the spectrophotometer. What is the most likely explanation?

   1. AThe extract is pure DNA, because 1.3 is the expected ratio
   2. BContamination with protein or phenol, which absorbs strongly at 280 nm
   3. CThe extract contains much RNA, which lowers the ratio below the pure DNA value of 1.8
   4. DResidual salt carry-over, which mainly changes the A260/A280 ratio
   Show answer and explanation

   Correct answer: B. Contamination with protein or phenol, which absorbs strongly at 280 nm

   Pure DNA gives about 1.8 and pure RNA about 2.0, so RNA would raise the ratio, not lower it. Protein and phenol absorb at 280 nm and pull the ratio down. Salt and guanidine are detected mainly by a low A260/A230 ratio.

   Reference: Green and Sambrook, Molecular Cloning: A Laboratory Manual, 4th ed., 2012

8. Question 8 · Molecular Techniques

   An RT-qPCR assay on extracted RNA gives a Ct of 33 in the no-reverse-transcriptase control and 22 in the test sample. What is the most likely cause of the control signal?

   1. AEfficient cDNA synthesis, because the enzyme is not needed
   2. BA degraded probe that raises background fluorescence
   3. CNormal behaviour, since a no-RT control is expected to give a Ct close to the sample
   4. DContaminating genomic DNA in the RNA preparation, amplified by the same primers
   Show answer and explanation

   Correct answer: D. Contaminating genomic DNA in the RNA preparation, amplified by the same primers

   Without reverse transcriptase RNA cannot become cDNA, so a signal means DNA was present. The fix is DNase treatment or intron-spanning primers. A good no-RT control is negative or very late, and the 11-cycle gap shows contamination is small but real.

   Reference: Bustin et al., The MIQE Guidelines, Clinical Chemistry, 2009

9. Question 9 · Biotechnology

   A technician transforms competent E. coli with 0.1 ng of plasmid, plates the whole culture and counts 250 colonies on antibiotic agar. What is the transformation efficiency?

   1. A2.5 x 10^3 cfu per microgram
   2. B2.5 x 10^9 cfu per microgram
   3. C2.5 x 10^6 cfu per microgram
   4. D2.5 x 10^2 cfu per microgram
   Show answer and explanation

   Correct answer: C. 2.5 x 10^6 cfu per microgram

   250 colonies from 0.1 ng gives 2,500 per ng, and 1 microgram is 1,000 ng, so the efficiency is 2.5 x 10^6 cfu per microgram. 2.5 x 10^3 is the per-nanogram value, 2.5 x 10^2 ignores the amount of DNA, and 2.5 x 10^9 over-converts the units.

   Reference: Green and Sambrook, Molecular Cloning: A Laboratory Manual, 4th ed., 2012

10. Question 10 · Biotechnology

    A hemocytometer count averages 50 cells per large square. Each large square holds 0.1 microlitre (10^-4 mL), and the sample was diluted 1 in 2 with trypan blue. What is the concentration of the original suspension?

    1. A5.0 x 10^5 cells per mL
    2. B1.0 x 10^6 cells per mL
    3. C5.0 x 10^3 cells per mL
    4. D1.0 x 10^7 cells per mL
    Show answer and explanation

    Correct answer: B. 1.0 x 10^6 cells per mL

    50 cells in 10^-4 mL is 5 x 10^5 cells per mL in the stained mix, and the 1 in 2 dilution doubles it to 1 x 10^6. 5 x 10^5 forgets the dilution factor, and the other two use the wrong volume per square.

    Reference: Freshney, Culture of Animal Cells: A Manual of Basic Technique, 7th ed., 2016

11. Question 11 · Genomics

    In trio exome sequencing, a child has a pathogenic heterozygous variant that is absent from both parents' blood. Which explanation, besides a true de novo event, changes the recurrence risk for future pregnancies?

    1. AParental germline mosaicism, in which the variant is present in some egg or sperm cells
    2. BAutosomal recessive inheritance from two carrier parents
    3. CMitochondrial inheritance passed from the mother, which would be visible in her blood sample
    4. DA common polymorphism, since parental absence proves it is benign
    Show answer and explanation

    Correct answer: A. Parental germline mosaicism, in which the variant is present in some egg or sperm cells

    A parent can carry the variant only in germ cells, so blood tests are negative yet more children could be affected. Recessive carriers would show the variant in blood, mitochondrial inheritance is not shown by this pattern, and absence in parents does not make a variant benign.

    Reference: Strachan and Read, Human Molecular Genetics, 5th ed., 2018

12. Question 12 · Bioinformatics

    In an alignment file, a read has a mapping quality (MAPQ) of 0. What does this usually mean?

    1. AThe read matches the reference exactly along its whole length and has been aligned perfectly
    2. BThe read maps equally well to more than one location, so its true origin is uncertain
    3. CThe read has very low base quality scores
    4. DThe read was removed as a PCR duplicate
    Show answer and explanation

    Correct answer: B. The read maps equally well to more than one location, so its true origin is uncertain

    MAPQ reflects the aligner's confidence in the read position, and 0 is typical for reads that fit several places equally well, such as in repeats. It does not describe base quality, perfect matching or duplicate status.

    Reference: Li et al., The Sequence Alignment/Map format and SAMtools, Bioinformatics, 2009

Genomic & Biotechnology Technician reference books and guidelines

Every question in this bank names the textbook or guideline its answer rests on. These are the sources our Genomic & Biotechnology Technician questions cite most often - the reading list to revise from alongside the bank.

Where your regulator publishes a reading list, use the editions it names. Exam questions are not taken from any one book.