2.1 Life As We Name ItLearning Outcomes:

Readings: 2: 46-47, 12: 313-338

Reading Quiz Due before class on Wednesday Sept 16th

Assignment Reminder: Welcome Survey on Vista due Wed. Sept. 23rd

New Assignment: Student Attitudes about Biology, complete by Monday Sept. 21st

Taxonomy:- a way of classifying and naming all living things- based on similarities between organisms

Classifying living organisms has been of importance to biologists for hundreds of years.Originally characteristics used were structural or morphological (how an organism looked). Organisms can also be classified based on organisms’ ecological roles, their chemical characteristics and now a lot of importance is place on how genetically similar organisms are (DNA comparisons).

Categorize the items below.Come up with a scheme for grouping items according to their similarity. For example one characteristic they all share is that they are worn on feet. Try to come up with a scheme to subdivide the shoes into different categories. Within each category you should be able to continue to create smaller and smaller groups until you have differentiated between each different shoe. For example you could first divide the shoes into two groups such as those made from natural materials vs. those made from synthetics. Then within each of these two groups you could continue to subdivide the shoes into smaller and smaller categories. Create your own scheme.

a) b) c) d) e) f)

g) h)

QUESTION: What did you do first to create your scheme?

1. Identify differences among domains and kingdoms. 2. Name common species using scientific nomenclature.

The Latin Binomial

What does this have to do with classification?The Latin binomial created a universal name (so scientists could all be sure they were talking about the same organism)Linneaus also created a hierarchical filing system (grouping species into a hierarchy of successively more general categories) which helped in understanding how organisms are related

The most general or inclusive group is the domain (which groups least similar organisms together)

Carolus Linnaeus (Carl von Linné) lived from 1707 –1778 in Sweden. In 1758 he published a book called ‘Systema Naturae’ (System of Nature) in which he presented his idea of naming living organisms according to a Latin binomial, or two-part Latin name

Example: Helianthus annuus, the sunflower (Latin taken originally from Greek helios = sun and anthos = flower and from Latin annuus = annual)Rules for the Latin Binomial:

1. underline or italicize, each part of the scientific name separately2. capitalize genus, The genus (first part of the name) is always capitalized,

the specific epithet (second part of the name) is always written in small letters

If the genus is known, but the species is not, then the abbreviation sp. is

Eg.: Domain EukaryaKingdom PlantaeDivision AnthophytaClass Dicotyledones Subclass Asteridae

OROrder AsteralesFamily AsteraceaeGenus HelianthusSpecies Helianthus annuus

Taxonomic hierarchy

Classification schemes have changed over timeThe earliest groupings just differentiated between Animals and Plants. Whittaker (1969) devised the 5 kingdom system, shown below. The Kingdom Monera composed the bacteria and the Kingdom Protista was a grab bag of mostly single-celled organisms with nuclei. Kingdoms vs. Domains

Within each domain there are a number of kingdoms. Within Domain Eukarya there are 4 major groups. Refer to Table 12.2 on Page 317Domain Kingdom Characterisitics ExampleArchaea (Crenarchaeota,

Euryarchaeota, Korarchaeota and Nanoarchaeota)

microscopic single cells, sperically, cylindrical, spiral or cube shaped.They are generally found in very harsh extreme environments eg extreme hot conditions such as hot sulfur pits, very saline, very cold, acidic or alkaline conditions.They differ from Bacteria in the composition of their cell walls and membranes as well as the machinery by which they synthesize DNA and proteins

Kingdom EuryarchaeotaMethanothermus ferviduslives in hot ponds’ producing methane, cannot tolerate oxygen

Bacteria numerous groups within the domain. Some call them kingdoms, some call them phyla. The number of groups at this classification level varies

microscopic single cells found in most environments on earth except a few of the most extreme. They lack a nucleus and arrange their genetic material in a single circular chromosome ( as do the Archaea). Cells are spherical, cylindrical or spiral in shape.

Domain Bacteria. spirochaeteBorrelia burgdorferi (FY =lyme disease)

Eukarya Plantae -obtain energy from the sun through photosynthesis. Their cells contain organelles called chloroplasts which are the sites of photosynthesis-multicellular and contain some type of pigments to absorb light and perform photosynthesis-cell walls contain cellulose

Eukarya Fungi -obtain energy from dead organic matter by secreting enzymes outside their cells to break down complex molecules and then absorb the simple molecules into their cells -produce spores to reproduce, multicellular, composed of thin filaments called hyphae, cell walls contain chitin

Eukarya Animalia - ingest their food and breakdown the complex molecules inside their bodies-multicellular, motile for part or all of life cycle-do not have cell walls, only cell membranes

Carl Woese (1980s) created domains to indicate how very different Archaebacteria (ancient bacteria) are from eubacteria (true bacteria) and Eukarya.Today the protists, eubacteria and archaea have been divided into a number of kingdoms to better reflect shared ancestry between groups.

Eukarya Protists There are numerous groups and how many should be called kingdoms vs. phyla is under debate

-organisms are generally unicellular (although there are exceptions in the algae) and obtain their food by one or more of the mechanisms of the other Eukarya kingdoms.-due to their diversity they have been divided into a number of different kingdoms

You will be shown a number of pictures of organisms in class. Identify which group you think each of these organisms belongs to and why you think so.

a) b)

c) d)

e) f)

g) h)

i) j)

k) l)

m) n)

o) p)

Questions to consider: 1. Members of the Kingdom Plantae have rigid cell walls made out of cellulose and some other tough polymers which support the plants and allow them to grow to some height. Members of Kingdom Animalia lack cell walls, so what do they use as a means of support to allow them obtain some height?

2. What some scientific advances or techniques which have likely caused scientists to change old classification schemes into 3 domains and numerous kingdoms within those domains?

3. Besides the Fungi which group or groups do you suspect that contain organisms which obtain energy from decaying organic matter?

4. What is a shared feature between all members of the Domain Eukarya?

5. If plants and many fungi are not motile during some phase of their life cycle, how do they distribute themselves into new areas to obtain necessary resources?

6. You go butterfly watching with a friend and using a field guide identify two species Polygonia progne and Polygonia satyrus. How do you know that they are in the same class order and family within the Biological classification hierarchy?

7. There are only several basic cell shapes for Archaea and Bacteria. What are other characteristics within these domains that would allow for more detailed classification into smaller subdivisions of organisms?

8. How would you determine which group this green organism belongs to? Even if you intuitively think you know which group it belongs to…how would you know for sure?