Prokaryotic Cell

Eukaryotic Cell

Autotrophs capture the light energy fromsunlight and convert it to chemical energythey use for food.

Heterotrophs must get energy by eating autotrophs or other heterotrophs.

Decomposers are heterotrophs that recycle dead organisms by breaking them down.

• Taxonomy is the science of groupingand naming organisms.

• Classification the grouping of information or objects based onsimilarities.

Why use a dead language?

•We only know about a fraction of theorganisms that exist or have existed on Earth.

•Taxonomists give a unique scientific name toeach species they know about whether it’s alivetoday or extinct.

• The scientific name comes from one of two“dead” languages – Latin or ancient Greek.

Devil Cat

Ghost Cat

Mountain Lion

Screaming Cat

Puma

Florida Panther

Cougar

•There are at least 50 common names for the animal shown on the previous 7 slides.

•Common names vary according to region.

•Soooo……why use a scientific name?

•a two name system for writing scientific names.•The genus name is written first (always Capitalized).

•The species name is written second (never capitalized).

•Both words are italicized if typed or underlined if hand written.

Example: Felis concolor or F. concolor

Which is the genus? The species?

Binomial Nomenclature

Phylogeny, the evolutionary history of anorganism, is the cornerstone of a branch of biology called systematic taxonomy.

Systematics, as systematic taxonomy is commonly called, is the study of the evolution of biological diversity.

A phylogenetic tree is a family tree that shows a hypothesis about the evolutionary relationships thought to exist among groups of organisms. It does not show the actual evolutionary history of organisms.

Why a hypothesis?

Phylogenetic trees are usually based on a combination of these lines of evidence:

Fossil record

Morphology (form and structure)

Embryological patterns of development

Chromosomes and DNA

Fossil

Morphology

Homologous Structures

Embryology

DNA

http://www.sciencecartoonsplus.com/

These animals have evolved similar adaptations for obtaining food because they occupy similarniches. What can you infer about their phylogeny from their geographic locations?

Convergent Evolution

Analogous Structures -

•Traits that are morphologically and functionally similar even though thereis no common ancestor.

Convergent evolution leads to……….

There are three basic assumptions with a phylogenic tree:

1. Organisms within a group are descended from a common ancestor.

2. There is a bifurcating (splitting in two) pattern of evolutionary changes.

3. Change in characteristics occurs in lineages over time.

• A key is a device for easily and quickly identifying an unknown organism.

• The dichotomous key is the most widely used type in biological sciences.

• The user is presented with a sequence of choices between two statements, couplets, based on characteristics of the organism. By always making the correct choice, the name of the organism will be revealed.

The Dichotomous Key

1.

A. one pair of wings

B. Two pairs of wings

The Three Domains

• Domain Archaea– Contains 1 kingdom – the Archaebacteria

•Domain Bacteria– Has 1 kingdom – the Eubacteria

•Domain Eukarya– Includes all kingdoms composed of organisms made

up of eukaryotic cells– Protista

– Fungi – Animalia – Plantae

The major classification levels,from most general to most specific

(several of these have subdivisions)

A group at any level is a taxon.

Kingdoms are divided into groups called phyla

Phyla are subdivided into classes

Classes are subdivided into orders

Orders are subdivided into families

Families are divided into genera

Genera contain closely related species

Species is unique

Categories within Kingdoms