Biology Lab Shahimermaid
wenell
lab_6.docxThis week, we will do Lab 6: Taxonomy. Taxonomists have the task of ordering the many millions of species that are living today AND who lived before and are now extinct into an organized system that reveals their current biological and past evolutionary relationships. This is a tall order indeed! The first scientist who set about organizing plants and animals into a cognitive system was Carolus Linnaeus (1707-1778), an 18th century Swedish professor, physician and naturalist. His actual name was Carl von Linné. However, in those days, the language of the university, research and science was Latin; so he Latinized his name and his taxonomic system.
Actually, his taxonomic system is ingenious, because it shows evolutionary relationships (even though he knew nothing about evolution then), it allows the addition of new species, rearrangements when errors were discovered, and it prevents duplication. In addition, more taxonomic steps may be added; in other words, it allows expansion without destroying any previous assignments.
He created two so-called Kingdoms, Plantae and Animalia (all in Latin), and then he worked his way ‘down’ several steps called taxa (singular: =taxon):
Kingdom – Phylum - Class – Order – Family – Genus – Species
The species is the least inclusive taxon, because all individuals of a given species may interbreed with each other and have fertile offspring. This is the official definition of a species! Linnaeus created a so-called binomial species description, meaning it has two names – name of the genus and a ‘trivial’ name, also called “the specific epithet”. For example, modern humans are called Homo sapiens (human the wise!)
There are strict nomenclature rules such as: The genus name is always capitalized, the specific epithet is not; the name has to be Latinized or underlined! Please remember this in your work!
Today, this system has been greatly expanded, because researchers now have the tools to study the many genetic and physical differences between and within groups. Prokaryotes and eukaryotes are now separated by so-called Domains; in fact, the world of the prokarya is so vast and varied, that now we have the following domains:
Domain Bacteria
Domain Archaea
And
Domain Eukarya
The latter includes the following Kingdoms:
Protista(it is currently being divided into further Kingdoms!); Fungi; Plantae; Animalia
Linnaeus could only describe the physical, morphological and behavioral aspects of any member of a given species; he had no knowledge of genes and genetics. However, he did remarkably well with grouping together different organisms that are biologically related. For example, he absolutely did not like monkeys, but he conceded to include them into the same Order as humans! Personally, he did not like it at all, but as a scientist he knew that they belonged into the order Primata.
Before you begin this week’s exercises, please read the Introduction in your Lab Manual very carefully.
Experiment 1: You will classify common objects that you will find in your lab kit. The only additional tool you need is a pencil. Then follow through with the flow chart and answer the questions in detail. Don’t leave anything out! Then you will choose 10 household items and arrange them as a taxonomic classification in another flow chart.
Experiment 2: Please study the table carefully and complete the Kingdoms, and then ‘walk’ each organism through the ‘tree’ (Figure 3), and complete the table. Answer all of the questions carefully!
