Chapter 17 Organizing Life's Diversity
Key Concepts: Chapter 17 1. List the 3 domains and the 6 kingdoms. 2. Our current system of classification was originally based on structures; scientists now base classification on what criteria? 3. List the 7 levels of classification. 4. What levels of taxonomy are used to name an organism in binomial nomenclature? 5. How many choices are at each step in a dichotomous key? 6. What are 2 of the requirements to be considered a species.
SWBAT Scale 4: Same as a 3.0 but I can make inferences & application to the SWBAT s 3: I COMPLETELY understand all parts of the SWBAT 2: I understand MOST of the SWBAT s with teacher help 1: I understand a little of the SWBAT s but need teacher help 0: I do NOT understand any part of the SWBAT s and need help!
Watch Video on Cladograms and answer the questions (a-c) in the packet. Cladograms Bozeman Science
Organisms can be classified based on physical similarities. However, modern classification is based on evolutionary relationships.
Physical similarities are not always the result of close relationships. Genetic similarities more accurately show evolutionary relationships.
16. Cladistics is classification based on common ancestry. 17. Phylogeny is the evolutionary history for a group of species. evidence from living species, fossil record, and molecular data shown with branching tree diagrams
Cladistics is a common method to make evolutionary trees. classification based on common ancestry species placed in order that they descended from common ancestor
18. Cladogram- a branching diagram that shows derived traits that differ between species. Live birth, nipples, birth canal Hair, mammary glands Photos by Dr. Gene Bakko, St. Olaf College Placentas, young nearly fully developed when born
19. Derived characters are traits shared in different degrees by clade members. basis of arranging species in cladogram 1 Tetrapoda clade 2 Amniota clade 3 Reptilia clade 4 Diapsida clade 5 Archosauria clade more closely related species share more derived characters represented on cladogram as hash marks EMBRYO PROTECTED BY AMNIOTIC FLUID FOUR LIMBS WITH DIGITS FEATHERS & TOOTHLESS BEAKS. SKULL OPENINGS IN FRONT OF THE EYE & IN THE JAW OPENING IN THE SIDE OF THE SKULL SKULL OPENINGS BEHIND THE EYE DERIVED CHARACTER
20. Phylogenetic Classification Models Remember, Phylogeny is the evolutionary history of a species
a. Cladistics - biological classification based on phylogeny b. Cladogram - model of phylogeny of a species 1. Identify derived traits Ex: light bones, down 2. Identify ancestral species that share traits 3. The more traits shared the more two species are related
21. Molecular evidence reveals species relatedness. a. Molecular data may confirm classification based on physical similarities. b. Molecular data may lead scientists to propose a new classification. DNA is usually given the last word by scientists.
The 6 Kingdoms Distinguished by the following characteristics: Structural similarities how are its parts similar Breeding behavior how does it mate Geographical distribution where is it found Biochemistry & Chromosome comparison DNA and chromosome # and size
The Six Kingdoms of Organisms *distinguished by cellular structure & methods of obtaining energy
1. Prokaryotes - lack nucleus, microscopic, unicellular a. Archaebacteria - live in extreme environments (Oxygen free) i. heterotrophs ii. autotrophs & chemosynthetic b. Eubacteria - strong cell wall, live in most habitats i. both heterotrophs and autotrophs
2. Eukaryotes -single or multi-cellular -membrane bound organelles
c. Protists i. moist environment ii. microscopic iii. auto and heterotrophs iv. mostly unicellular v. "hodge podge"
d. Fungi i. decomposers (absorption) ii. cannot move iii. unicellular or multicellular
e. Plants i. multicellular ii. autotrophs, photosynthetic - green
f. Animals i. multicellular ii. heterotrophs iii. mobile
Classification is always a work in progress. The tree of life shows our most current understanding. New discoveries can lead to changes in classification. Until 1866: only two kingdoms, Animalia and Plantae 1866: all single-celled organisms moved to kingdom Protista 1938: prokaryotes moved to kingdom Monera 1959: fungi moved to own kingdom Animalia Fungi 1977: kingdom Monera split into kingdoms Bacteria and Archaea Plantae Bacteria Protista Archea
The current tree of life has three domains.
The three domains in the tree of life are Bacteria, Archaea, and Eukarya. Domains are above the kingdom level. proposed by Carl Woese based on rrna studies of prokaryotes domain model more clearly shows prokaryotic diversity
Key Concepts: Chapter 17 1. List the six kingdoms. 2. Our current system of classification was originally based on structures; scientists now base classification on what criteria? 3. List the 7 levels of classification. 4. What levels of taxonomy are used to name an organism in binomial nomenclature? 5. How many choices are at each step in a dichotomous key? 6. What are 2 of the requirements to be considered a species.
SWBAT Scale 4: Same as a 3.0 but I can make inferences & application to the SWBAT s 3: I COMPLETELY understand all parts of the SWBAT 2: I understand MOST of the SWBAT s with teacher help 1: I understand a little of the SWBAT s but need teacher help 0: I do NOT understand any part of the SWBAT s and need help!
Now, complete Packet pages 15-16 & 20. This is due at the end of the hour (unless your teacher says otherwise) so work efficiently.
Now, go to the following link and complete the webquest. This is due at the end of the hour (unless your teacher says otherwise) so work efficiently. Cladogram Webquest If you can t open it from here, go to my website, under Biology A Notes, Unit 3-Classification and look for Classifying Organisms Webquest.