Biology - Unit 2

Taxonomy

The science of naming, identifying, and classifying of species

Dichotomous key

• A way of sorting things into categories

• Di means two

• Each level has one feature and has two options

Biodiversity

The variety of life in the world or in a particular habitat or ecosystem

Genetic Diversity

Inherit unique combinations of genetic information from there parents

EX. hair or eye color

Species Diversity

Both the variety of species in an ecosystem and the number within those

Structural diversity

The range of physical shapes and sizes within a habitat of the ecosystem

Evolutionary Changes

Physical and behavioral changes that occur within an entire population over time

Aristotle

-2000 years ago

• made the first attempt of classification

• two main groups (animalia and plantae)

• animals were based on where they live (land, water, or air)

• plants were based on structure (herbs, shrubs, or trees)

Carl Linneaus

• Father of Taxonomy

• Swedish botanist (1701-1778)

• based on structural similarities in organisms

• created taxon or groupings in a hierarchy (kingdom, phylum, class, order, family, genus, species)

• created the binomial nomencloture (to part naming system)

Ernst Haekel

• proposed a third kingdom (protista)

Robert Whittaker

• created a 5 kingdom classification on number of cells (multi or uni), presence or absence of a nucleus, heterotroph or autotroph

• added monerans and fungus (could not photosynthesize)

• Protists, plante, animalia, monerans, and fungus

Carl Woese

• microbiologist and biophysicist

• took monerans and divided it into Archea and Eubacteria

• created three domains

Prokaryotes

• Organisms with no nucleus

• Archea and bacteria

Eukaryotes

• organisms with a nucleus

• Fungi, protista, animalia, plantae

Animalia

• All mulitcellular with no cell walls

• Heterotrophs (consumers)

• Live in both aquatic and terrestrial habitats

Fungus

• Multicellular

• Heterotrophs (none synthesize)

• All have cell walls contain chitin

• Most are terrestrial

Protista

• Most are multicellular

• Some have cell walls

• Some reproduce sexually, most asexually

• Some are heterotrophs, most autotrophs

• Most are aquatic some are terrestrial

Eubacteria

• All unicellular

• All prokaryotic

• All reproduce asexually through binary fission

• All cell walls contain peptidogylcan

• Some cause disease

Archea

• All unicellular

• All prokaryotic

• All have cell walls

• They can live in extreme environments

Theory of Evoloution

All living things come from a common ancestor, but also change and adapt to environments

Phylogeny

The evoloutionary history of an organism

Phylogenetic tree

Show the evoloutionary relationships thought to exist among different groups of organisms

Morphology

Uses the structure of an organism for classification

Homogolous structure

Structures in different speciesthat are similar because of common ancestry

Ex. Forearm of a human and a wing of a bat

Anaglolous structure

Similar in function, but not in structure

EX. wings of a bird and butterfly

Vestigil structure

reduced in size and seems to be a “leftover” from previous ancestors

Cellular organization

similarity in cell structure provides evidence that organisms may be related

Evolutionary descent

groups organisms into categories that represent lines or evolutionary descent or phylogeny

Biochemical similarities

similarities of compound chemicals found within cells can be used as evidence to show relationships between organisms

Genetic Similarities

the more similar DNA sequences of two species, show how closely related organisms are

Embryological similarities

some organisms show no similarities as adults, but are very similar as embryos

Amnion Sac

a sac filled of fluid that surrounds the embryo

Cladistics

• new method of classifying organisms

• identifies the characteristics of organisms that are “evolutionary innovations”

Shared Characters

All members of a group have in common

EX. hair in mammals

derived characters

evolved only within the group under consideration

Clades

A group of organisms that includes an ancestor plus all of it’s descendants

Cladogram

shows the evolutionary relationships among a group of organisms

Traditional classification

Pro: classifies by observing morphological characteristics and simple and convenient

Con: Over looks less obvious characteristics

Phylogenetic classification

Pro: uncovers generations of evolutionary relationships

Con: Uncovering evolutionary relatedness that may go back millions