1. Taxonomy, Kingdoms,
Classifications

2. • To study the diversity of life, biologists use
a classification system to name organisms
and group them in a logical manner
• Binomial nomenclature: two part scientific
name: first part is the genus (closely
related species) – second part is name
unique to the species
• Ex: Ursus maritimus

3. Carolus Linnaeus (1707-1778)
• Hierarchical system of classification with 7
levels: ordered from smallest to largest
• Species, genus, family, order, class,
phylum, and kingdom (animalia, plantae)
• Organisms were grouped based on visible
similarities and differences

4. Evolutionary classification
• Phylogeny – evolutionary relationships
among organisms (Darwin)
• Organisms are grouped into catagories
that represent lines of evolutionary
descent and not just physical similarities
(evolutionary classification)
• Derived characters; appear in recent
lineage but not in older member

5. Cont.
• Derived characters can be used to
construct a cladogram, a diagram that
shows the evolutionary relationships
among a group of organisms

6. DNA and RNA
• Genes of many organisms show important
similarities at the molecular level.
Similarities in DNA can be used to help
determine classification and evolutionary
relationships
• Molecular clock – uses DNA comparisons
to estimate the time that two species have
been evolving independently

7. Kingdoms
• First - Animalia and plantae
• Additional – Monera (split into Eubacteria and
Archaebacteria), Protista, Fungi,
• Current classification has the above 6 kingdoms
• Domain – 3 categories (larger than kingdom)
• Bacteria
• Archaea
• Eukarya

8. Domains 3 categories (larger than
kingdom)
• Bacteria – unicellular, prokaryotic
• Archaea – extremophiles
• Eukarya – all organisms that have a
nucleus

9. Protist:
• Protista – means “very first” 1.5 billion
• Margulis – evolved from mitochondria and
chloroplasts found in eukaryotic cells may
have descended from aerobic and
photosynthetic prokaryotes that began to
live inside larger cells
• Protista - Eukaryotes that do not belong to
plantae, animalia, fungi or a prokaryote

10. Cont.
• Has nucleus and membrane-bound
organelles
• Most unicellular
• Animallike: heterotrophs,
• Plantlike: autotrophs
• Funguslike: decomposers

11. Fungi
• Heterotrophs
• Absorb nutrients (hyphae/mycelium)
• Have cell walls (chitin)
• Reproduced with fruiting body
• Asexually – hyphae break off and grow or
spore production
• Two mating types (+) and (-) meet, fuse,
diploid zygote enters meiosis and
completes reproduction.

12. Plantae
• Multicellular eukaryotes that have cell
walls made of cellulose, carry out
photosynthesis (trees, shrubs, grasses,
mosses, ferns)
• Life cycle has 2 alternating phases:
• Diploid (2N) – sporophyte (spore
producting)
• Haploid (N) – gametophyte (gamete
producing)

13. Survival
• Sunlight
• Water and minerals
• Gas exchange
• Transport of water and nutrients
• Evolved from early multicellular green
algae

14. Animalia
• Multicellular, eukaryotic heterotrophs lack
cell walls
• Invertebrates – no back bone (squid, sea
stars, microrganisms)
• Vertebrates – with back bones (humans,
reptiles, birds, mammals)

15. Survival
• Homeostasis – stable state maintained by
feedback mechanisms
• Feedback inhibition – product or results
stops process or limits the process
• Feeding - nutrients
• Respiration – transport of gases (O2 and
CO2)
• Circulation – movement of material in
organism

16. Cont.
• Excretion – removal of waste products
• Response – nervous systems (stimuli)
• Movement – muscle or muscle-like tissue
that allows for mobility
• Reproduction – production of offspring
(usually through sexual reproduction)

17. Animal evolution
• Complex animals tend to have high levels
of cell specialization and internal body
organization, bilateral body symmetry,
front end or head with sense organs
(cephalization), and body cavity
• Cell → tissue → organs → organ systems

18. Sponges
• ancient animals
• Multicellular, heterotrophs, with some
specialized cells, asymmetrical
• Movement of water through a central
cavity provides a simple mechanism for
feeding (filtering), respiration, circulation,
excretion

19. Cnidaria
• Soft-bodied, carnivorous animals with
stinging tentacles arranged in circles
around their mouths, simplest animals to
have body symmetry and specialized
tissues
• Life cycle: polyp and medusa
• Jellies, hydras, anemones,