280 likes | 615 Views
BOTANY. IN THE BIGNING, A LOOK AT THE ORGANISMS, and HOW WE STUDY PLANTS AND NAME THEM. HOW OLD IS THE EARTH. The generally accepted age for the Earth and the rest of the solar system is about 4.5 billion years (plus or minus about 1% ). Gases present on earth in the beginning.
E N D
BOTANY IN THE BIGNING, A LOOK AT THE ORGANISMS, and HOW WE STUDY PLANTS AND NAME THEM
HOW OLD IS THE EARTH • The generally accepted age for the Earth and the rest of the solar system is about 4.5 billion years (plus or minus about 1%)
Gases present on earth in the beginning • Earth's atmosphere was formed mostly from the out-gassing of such volatile compounds as water vapor, carbon monoxide, methane, ammonia, carbon dioxide, nitrogen, hydrochloric acid and sulfur produced by the constant volcanic eruptions that besieged the Earth. It had no free oxygen.
Some thoughts on organisms • First organisms got energy from electron transfer Fe++ to Fe +++ • Photo synthesis produces O2 O2 + uv light = O3 • Cyanobacteria did it
Some thoughts on organisms cont. • Organisms start moving from deeper colder water to shallower warmer water • Numbers of organisms increased • Ozone protected the earth from the suns deadly uv light as it does still today • Nitrogen fixing goes on in an environment free of O2 occurred early on and still is going on today
Building blocks of organisms • Nitrogen N • Oxygen O • Hydrogen H • Carbon C • My shortcuts: CHO lipids and carbohydrate, CHON protean
Prokaryotes • Unicellular, small < 10m in size • No organelles • Cell membrane • Divides by fission • Nucleus does not divide equally (no nuclear envelope) therefore not a true nucleus
Eukaryotes • All the rest of the organisms • True nucleus with all its contents with a nuclear membrane • Multiple organelles
Time line • 3.8 to 2.5 billion years ago, first life began to appear • Earth's initial life forms were bacteria which could survive in the highly toxic atmosphere that existed during that time. • About 2.5 billion years ago, oxygen-forming photosynthesis began to occur. The first fossils, in fact, were a type of blue-green algae that could photosynthesize
Time line cont. • Free oxygen began to build up around 1.8 billion years ago which made way for the emergence of life as we know it today • First eukoryotes, need O2 • 1.7 mya animals appear • 1.5 mya trees
Plant names and classification Chapter 16
Development of kingdom concept • Two Kingdoms 1. Plantaenonmotile, photosynthetic autotrophs 2. Animaliamotile, ingestiveheterotrophs Three kingdoms • 1. First two kingdoms plus was the Protoctista (Protista) contained organisms that did not develop complex tissues • Fourth kingdom was the Monerasingle-celled prokaryotic protists
Development of kingdom concept cont. • Five Kingdoms 1. Proposed by R. H. Whittaker in 1969 • 2. Divided complex organisms on forms of nutrition • a. Photosynthesis: Plantae Kingdom • b. Ingestion of solid food: Animalia Kingdom • c. Absorption of nutrients in solution: Fungi Kingdom • 3. Divided protists on basis of cell type • a. Prokaryotes: Monera Kingdom • b. Eukaryotes: Protista Kingdom
Classification of Major Groups • Categories (each higher category contains one or more of the immediately subordinate categories) • 1. Kingdom • 2. Phylum (Previously Division for Plants) • 3. Class • 4. Order • 5. Family • 6. Genus • 7. Species
Example of Classification: The Onion • 1. Kingdom: Plantae • 2. Phylum: Magnoliophyta • 3. Class: Liliopsida • 4. Order: Liliales • 5. Family: Liliaceae • 6. Genus: Allium • 7. Species: Alliumcepa L. • • specific epithet followed by name of the author (usually in abbreviated form if the author is well know like, Linnaeus)
How do we refer to plants • A. Scientific Names • 1. Allow organisms to be identified anywhere, no matter what language is spoken • 2. Each organism has a unique name • B. Common Names 1. Same organism may have many common names • 2. Different, but closely related species may have the same common name
Binomial System of Nomenclature • A. Theophrastus (3rd century B.C.) • classified almost 500 plants into trees, shrubs, and herbs • B. Herbalists • 1. Use of descriptive Latin phrase names • 2. Organisms grouped into genera • a. Menthafor mints • B. Populusfor poplars
Binomial System of Nomenclature cont. • C. Carolus Linnaeus (1707-1778) • Published Species Plantarum in 1753 a. Included referenced list of all Latin phrase names b. Changed some of the phrases to reflect relationships, placing related species in the same genus • c. Established binomials by using marginally placed single word for each species • d. Organized all known plants into 24 classes
Binomial System of Nomenclature cont. • International Code of Botanical Nomenclature • a. Recognizes Linnaeus' Species Plantarum as starting point for botanical nomenclature • b. Sets down rules for naming and classifying