This document provides an overview of biological classification systems and kingdoms. It discusses how biologists classify organisms based on visible similarities and evolutionary relationships. Organisms are grouped in a hierarchical system with seven main levels from most specific (species) to most general (kingdom). There are currently six recognized kingdoms - Animalia, Plantae, Fungi, Protista, Archaea, and Bacteria. Molecular comparisons of DNA are also used to determine evolutionary relationships and estimate times of species divergence. The key kingdoms are described in terms of their basic characteristics.

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
• Lynn 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 – Plants basics
• 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 – 7 basic requirements
• Homeostasis – stable state maintained
by feedback mechanisms
• Feedback inhibition – product or results
stops process or limits the process
1.Feeding - nutrients
2.Respiration – transport of gases (O2 and
CO2)
3.Circulation – movement of material in
organism

16. Cont.
4. Excretion – removal of waste products
5. Response – nervous systems (stimuli)
6. Movement – muscle or muscle-like
tissue that allows for mobility
7. 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,