Completed genomes: bacterium, nematode, plant, human MCQs With Answer

Introduction: This quiz set covers completed genomes of representative organisms — bacterium, nematode, plant and human — with emphasis on concepts important for M.Pharm students in Bioinformatics and Computational Biotechnology. Questions focus on history of landmark genome projects, sequencing strategies, assembly and annotation challenges, genomic features (gene density, introns, repeats), comparative genomics, and applications in drug discovery and pharmacogenomics. Understanding these completed genomes gives insight into model organisms used in functional studies, how reference genomes are constructed and maintained, and how genomic data translate to therapeutic target identification, ADME gene variability and precision medicine. The questions combine factual recall with applied interpretation relevant to pharmaceutical research.

Q1. Which organism had the first complete genome sequence of a free-living bacterium published in 1995?

• Mycoplasma genitalium
• Escherichia coli K-12
• Haemophilus influenzae Rd
• Streptococcus pneumoniae

Correct Answer: Haemophilus influenzae Rd

Q2. The complete genome of Caenorhabditis elegans was important because it was:

• The first bacterial genome sequenced
• The first plant genome sequenced
• The first complete animal (multicellular eukaryote) genome sequenced
• The first primate genome sequenced

Correct Answer: The first complete animal (multicellular eukaryote) genome sequenced

Q3. Which plant was the first to have its nuclear genome fully sequenced and became a reference model for plant genomics?

• Zea mays (maize)
• Oryza sativa (rice)
• Arabidopsis thaliana
• Triticum aestivum (wheat)

Correct Answer: Arabidopsis thaliana

Q4. The Human Genome Project produced a high-quality draft in 2000 and a finished sequence in 2003. One major difference between the draft and the finished sequence was:

• Removal of all exons from the reference
• Closure of many gaps and improved representation of repetitive regions
• Conversion of the genome from DNA to RNA sequences
• Elimination of single nucleotide polymorphisms (SNPs)

Correct Answer: Closure of many gaps and improved representation of repetitive regions

Q5. Which sequencing strategy was primarily used for the Haemophilus influenzae genome project and influenced many early genome projects?

• Chromatin immunoprecipitation sequencing
• Whole-genome shotgun sequencing
• RNA-Seq
• Bisulfite sequencing

Correct Answer: Whole-genome shotgun sequencing

Q6. In terms of genome architecture, a key difference between bacterial genomes and human genomes is:

• Bacterial genomes lack any coding sequences
• Bacterial genomes are generally circular and have higher gene density with few introns
• Human genomes are circular and have no repeats
• Human genomes contain operons similar to bacteria

Correct Answer: Bacterial genomes are generally circular and have higher gene density with few introns

Q7. Which metric describes the contig length such that 50% of the assembled genome is in contigs of that length or longer and is commonly reported for assemblies?

• GC content
• N50
• Read depth
• Q-score

Correct Answer: N50

Q8. Annotation of completed genomes typically involves which of the following steps?

• Only wet-lab PCR validation without any computational prediction
• Prediction of genes, assignment of function, identification of regulatory elements and noncoding RNAs
• Removal of all repetitive sequences from the sequence file
• Translation of entire genome into a single protein sequence

Correct Answer: Prediction of genes, assignment of function, identification of regulatory elements and noncoding RNAs

Q9. Comparative genomics using completed genomes helps identify conserved drug targets by:

• Comparing only intron sequences across species
• Identifying orthologous genes conserved in pathogens but absent or divergent in humans
• Prioritizing genes with the highest number of SNPs in humans
• Focusing solely on mitochondrial genomes

Correct Answer: Identifying orthologous genes conserved in pathogens but absent or divergent in humans

Q10. Which statement about transposable elements in plant and human completed genomes is correct?

• Transposable elements are rare and account for <1% of both plant and human genomes
• They are abundant, often making up a major portion of genome size and complicate assembly and annotation
• They occur only in bacterial genomes and not in eukaryotes
• They are identical in sequence across all species

Correct Answer: They are abundant, often making up a major portion of genome size and complicate assembly and annotation

Q11. The reference human genome contains alternate haplotypes and patch releases because:

• Human genomes are completely identical across all individuals
• There is substantial structural and sequence variation across populations that require updates and alternative representations
• Sequencing errors are impossible to correct once published
• Reference genomes are immutable single molecule sequences

Correct Answer: There is substantial structural and sequence variation across populations that require updates and alternative representations

Q12. Which completed genome project provided a key model for studying gene regulation, development and pharmacological targets in multicellular animals?

• Haemophilus influenzae
• Caenorhabditis elegans
• Arabidopsis thaliana
• Escherichia coli K-12

Correct Answer: Caenorhabditis elegans

Q13. In bacterial genome annotation, an operon is best described as:

• A group of neighboring genes transcribed together under control of a single promoter
• A eukaryotic intron-exon structure
• Only a protein-coding gene with no regulatory sequence
• A viral integration site exclusively

Correct Answer: A group of neighboring genes transcribed together under control of a single promoter

Q14. Which challenge is particularly significant when assembling plant genomes compared to many bacterial genomes?

• Plant genomes are always smaller than bacterial genomes
• High repeat content, polyploidy and large genome size complicate assembly
• Absence of genes in plant genomes
• Plant DNA cannot be sequenced by modern platforms

Correct Answer: High repeat content, polyploidy and large genome size complicate assembly

Q15. Which completed genome significantly advanced pharmacogenomics by providing a resource to study human genetic variation affecting drug response?

• Human reference genome from the Human Genome Project
• First bacterial genome Haemophilus influenzae only
• Arabidopsis thaliana plant genome only
• Caenorhabditis elegans genome only

Correct Answer: Human reference genome from the Human Genome Project

Q16. When comparing completed microbial genomes, detection of horizontal gene transfer (HGT) is commonly inferred by:

• Uniform GC content across the entire genome
• Regions with atypical GC content, presence of mobile elements and phylogenetic incongruence
• Observing only single-copy housekeeping genes
• Assuming all genes arose vertically without transfer

Correct Answer: Regions with atypical GC content, presence of mobile elements and phylogenetic incongruence

Q17. Which resource or tool is specifically used to view and query completed genomes, gene models and annotations interactively?

• Genome browsers such as UCSC Genome Browser or Ensembl
• Microsoft Word
• Spreadsheet software without genomic plugins
• Electron microscopy images

Correct Answer: Genome browsers such as UCSC Genome Browser or Ensembl

Q18. In the context of completed genomes, the term “reference genome” means:

• An artificially synthesized genome with no relation to organisms
• A representative, curated linear sequence assembly used as a coordinate system for mapping and annotation
• A collection of raw sequencing reads before assembly
• A list of metabolic pathways only

Correct Answer: A representative, curated linear sequence assembly used as a coordinate system for mapping and annotation

Q19. Which completed genome demonstrated early use of comparative genomics to predict gene function by conservation across species?

• The first bacterial (Haemophilus influenzae) and subsequent model eukaryotic genomes like C. elegans and yeast
• Only mitochondrial genomes ever
• Random fragment libraries with no annotations
• Unsequenced genomes

Correct Answer: The first bacterial (Haemophilus influenzae) and subsequent model eukaryotic genomes like C. elegans and yeast

Q20. For M.Pharm students, why is knowledge of completed genomes (bacterial, nematode, plant, human) directly relevant to drug discovery?

• Completed genomes are unrelated to pharmacology and only of historical interest
• They provide targets, pathways, orthologs, resistance mechanisms and pharmacogenomic variants that inform target validation and personalized therapy
• They prevent all adverse drug reactions from occurring
• They make clinical trials unnecessary

Correct Answer: They provide targets, pathways, orthologs, resistance mechanisms and pharmacogenomic variants that inform target validation and personalized therapy

Download