Free SCFHS Genomic & Biotechnology Technician mock test

Genomic & Biotechnology Technician sample questions with answers

10 more original exam-style Genomic & Biotechnology Technician questions, worked in full. They are not real or recalled exam questions, and none of them is in the mock above or on the bank page, so sit the mock first if you have not.

1. Question 1 · Basic Laboratory Skills

   Human cell lines are handled at biosafety level 2. Why is a Class II biological safety cabinet preferred for this work?

   1. AHEPA-filtered airflow protects the operator, the cells and the environment
   2. BIt sterilises the work surface with ultraviolet light
   3. CIt removes chemical vapours by exhausting room air
   4. DIt maintains a constant 37 degree Celsius temperature for cell growth
   Show answer and explanation

   Correct answer: A. HEPA-filtered airflow protects the operator, the cells and the environment

   Class II cabinets give inward airflow for the operator, HEPA-filtered downflow for the product and filtered exhaust for the environment. UV is only an adjunct, they do not protect against volatile chemicals, and they do not provide an incubator temperature.

   Reference: CDC/NIH, Biosafety in Microbiological and Biomedical Laboratories, 6th ed., 2020

2. Question 2 · Biotechnology

   A gene therapy design needs stable, long-term expression in dividing cells. Which vector choice fits best?

   1. AAn AAV vector, because it integrates at random in dividing cells
   2. BA lentiviral vector, because it integrates into the host genome
   3. CA naked plasmid, because it replicates forever in human cells
   4. DAn adenoviral vector, because it persists unchanged for years
   Show answer and explanation

   Correct answer: B. A lentiviral vector, because it integrates into the host genome

   Lentiviral vectors integrate and so are passed on to daughter cells. AAV genomes stay mostly episomal and are diluted in dividing cells, plasmids are lost, and adenoviral genomes also remain episomal and are transient.

   Reference: Gene and Cell Therapy: Biology and Applications, 1st ed., 2018

3. Question 3 · Biotechnology

   Myeloma cells and B cells have been fused and are now grown in HAT medium. What does the medium achieve?

   1. AIt kills unfused B cells while the myeloma cells survive and grow
   2. BIt selects for cells that lack antibody genes
   3. CIt kills unfused myeloma cells, so that hybrids survive
   4. DIt stops the cells in the dish from dividing
   Show answer and explanation

   Correct answer: C. It kills unfused myeloma cells, so that hybrids survive

   Myeloma partners lack HGPRT and cannot use the salvage pathway when aminopterin blocks the de novo pathway, while unfused B cells die naturally. Only hybrids survive.

   Reference: Kohler and Milstein, Nature 1975;256:495-497

4. Question 4 · Bioinformatics

   In a VCF file, a genotype field reads 0/1. What does it mean?

   1. AThe sample is homozygous for the reference allele at this position in both copies
   2. BThe sample is homozygous for the alternate allele at this position in both copies
   3. CThe sample is heterozygous: one reference and one alternate allele
   4. DThe genotype could not be called because of too few supporting reads
   Show answer and explanation

   Correct answer: C. The sample is heterozygous: one reference and one alternate allele

   0/1 means one reference and one alternate allele. 0/0 is homozygous reference, 1/1 is homozygous alternate and ./. is a missing call.

   Reference: Danecek et al., Bioinformatics 2011;27:2156-2158

5. Question 5 · Basic Laboratory Skills

   A technician receives a new flammable solvent and is unsure how to store it safely. Which document gives product-specific storage, incompatibility and spill-response information?

   1. AThe manufacturer's safety data sheet for that exact product
   2. BThe product price list and ordering page in the supplier catalogue
   3. CThe label of a similar solvent already on the shelf
   4. DThe service manual of the fume hood
   Show answer and explanation

   Correct answer: A. The manufacturer's safety data sheet for that exact product

   The safety data sheet is the standard source of hazards, storage, incompatibilities and spill response for a specific product. A price list has no safety content, a similar product may have different hazards, and a hood manual covers the equipment only.

   Reference: United Nations, Globally Harmonized System of Classification and Labelling of Chemicals (GHS), 9th rev. ed., 2021

6. Question 6 · Biotechnology

   A vector is cut with a single restriction enzyme and then treated with alkaline phosphatase before ligation with an insert. What is the purpose of the phosphatase step?

   1. AIt adds phosphate groups so that ligase works faster
   2. BIt removes 5' phosphates so the vector cannot re-close
   3. CIt cuts the insert at a second site to match the vector
   4. DIt destroys the restriction enzyme left in the tube
   Show answer and explanation

   Correct answer: B. It removes 5' phosphates so the vector cannot re-close

   A vector cut at one site has compatible ends and can simply re-close. Removing its 5' phosphates blocks this because ligase needs them, while the insert still supplies phosphates. Phosphatase does not add phosphates, cut DNA or inactivate the restriction enzyme.

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

7. Question 7 · Genomics

   A man with an X-linked recessive disorder has children with a woman who is not a carrier. What is the expected outcome?

   1. ASons are affected and daughters are unaffected non-carriers
   2. BHalf of the sons are affected and half of the daughters are carriers
   3. CDaughters are carriers and sons are unaffected
   4. DNeither sons nor daughters inherit the variant
   Show answer and explanation

   Correct answer: C. Daughters are carriers and sons are unaffected

   A father passes his X chromosome to every daughter and his Y to every son. Daughters therefore carry the variant, and sons get a normal X from the mother. The other options describe a carrier mother or autosomal inheritance.

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

8. Question 8 · Bioinformatics

   After large FASTQ files are copied from the sequencer to a server, which check best shows that the copies are not corrupted?

   1. ACompare the file names and creation dates in the folder listing
   2. BOpen the first ten reads and read them by eye
   3. CCheck that the copy has the same file extension
   4. DCompare checksums, for example MD5, of the original and the copy
   Show answer and explanation

   Correct answer: D. Compare checksums, for example MD5, of the original and the copy

   A checksum changes if even one bit differs, so matching values show the copy is identical. Names, dates and extensions can match while content is damaged, and viewing a few reads cannot detect corruption deeper in the file.

   Reference: Buffalo, Bioinformatics Data Skills, 2015

9. Question 9 · Bioinformatics

   FastQC shows base quality falling below Q20 in the last 20 positions of 150-base reads. Which step usually comes next?

   1. ADiscard the whole run and repeat the sequencing
   2. BConvert the FASTQ files to FASTA format so that the quality problem is removed
   3. CTrim the low-quality ends, and any adapter sequence, before alignment
   4. DAlign as they are, because aligners ignore base quality
   Show answer and explanation

   Correct answer: C. Trim the low-quality ends, and any adapter sequence, before alignment

   Quality usually declines toward the 3' end, and trimming those bases keeps most of the data and avoids false mismatches. A run is rarely discarded for this, FASTA drops the quality information, and aligners do use base quality.

   Reference: Bolger, Lohse and Usadel, Trimmomatic: a flexible trimmer for Illumina sequence data, Bioinformatics, 2014

10. Question 10 · Professional Practice/ Ethics

    Exome sequencing for a child's epilepsy reveals a pathogenic variant in a hereditary cancer gene, unrelated to the test request. What should the technician do?

    1. ATelephone the parents directly to tell them about the finding
    2. BDelete the variant from the data because it is outside the request
    3. CAdd the variant to a shared research database for other groups
    4. DRecord it and refer it to the clinical geneticist
    Show answer and explanation

    Correct answer: D. Record it and refer it to the clinical geneticist

    Unrequested findings are handled under the consent form and the laboratory's policy by the responsible clinical staff. A technician should not disclose results, delete data or share identifiable findings without consent.

    Reference: Miller et al., ACMG recommendations for reporting of secondary findings in clinical exome and genome sequencing, v3.2, Genetics in Medicine, 2023