Question 1: Define the Linnaean System of classification and explain its primary purpose.

Answer: The Linnaean System is a hierarchical method of classifying organisms based on shared characteristics, primarily using binomial nomenclature to assign genus and species names. Its purpose is to organise living organisms systematically for easier identification and study.

Question 1: What are the main taxonomic ranks in the Linnaean hierarchy from broadest to most specific?

Answer: Kingdom, Phylum, Class, Order, Family, Genus, Species.

Question 2: Describe how binomial nomenclature helps in the identification of organisms.

Answer: Binomial nomenclature assigns each species a two-part Latin name consisting of the genus and species identifiers, ensuring a unique and standardised naming system globally.

Question 1: A forensic scientist identifies a specimen as belonging to the genus 'Canis' with a 95% confidence level. If the total number of known species in the genus is 15, estimate the probability that a randomly selected species from this genus matches the specimen.

Answer: 0.95 * 1/15 ≈ 0.063 or 6.3%

Question 1: Design a basic outline for a forensic experiment that uses the Linnaean System to identify a plant species from a crime scene. Include the key variables and safety precautions.

Answer: Students should propose collecting plant samples, using morphological analysis and DNA sequencing to classify the specimen according to taxonomic ranks. Variables include sample type, preservation method, and analysis technique. Safety precautions involve wearing gloves, lab coat, and eye protection, and handling samples in a contamination-free environment.

Question 1: A set of insect samples found on a body are classified into three genera: 'Lucilia', 'Calliphora', and 'Sarcophaga'. The majority of the specimens belong to 'Lucilia'. What does this suggest about the post-mortem interval, and how does the Linnaean System assist in this analysis?

Answer: The predominance of 'Lucilia' suggests the body was likely exposed to this insect's life cycle stage during decomposition, helping estimate the post-mortem interval. The Linnaean System enables precise identification and comparison of species, facilitating accurate forensic timelines.

Question 1: Explain how the Linnaean System is used in forensic investigations to identify unknown biological samples. Include the importance of taxonomic hierarchy and binomial nomenclature in your answer.

Answer: The Linnaean System provides a structured hierarchy for classifying organisms, aiding forensic scientists in systematically narrowing down the identity of biological samples. By analysing morphological traits and using binomial nomenclature, investigators can match samples to known species, which can be crucial in crime scene analysis, victim identification, or tracking illegal wildlife trade. The taxonomic hierarchy helps in organising organisms from broad to specific categories, improving accuracy and efficiency in identification.

Question 1: Discuss how advancements in molecular biology, such as DNA barcoding, complement the traditional Linnaean System in forensic science. What are the benefits and limitations of these methods?

Answer: DNA barcoding uses specific DNA sequences to identify species rapidly, enhancing the traditional Linnaean System by providing precise molecular identification. Benefits include increased accuracy, speed, and ability to identify cryptic species. Limitations involve high costs, need for specialised equipment, and dependence on comprehensive genetic databases.