Bio 2201 Unit 2
The Road to the Six Kingdoms A 2011study estimated there are about 8.6 million species on earth. Only 1.8 million species have been identified and named.
*Chromista is a sub-kingdom group that contains all algae, which technically fall under Kingdom Protista.
Biodiversity changes everyday as species go extinct, while others are just discovered. Scientists have discovered 24 new species of wildlife in the South American highlands of Suriname, including a frog with fluorescent purple markings. (2007) An atelopus frog
http://news.nationalgeographic.com/news/2010/07/photogalleries/100707- new-species-weird-deep-sea-atlantic-ocean-science-pictures/ http://www.treehugger.com/galleries/2010/05/top-ten-new-species-2010- psychedelic-frogfish-dracula-minnow.php Assignment #1- Post a picture on schoology of a cool new species that has been discovered in the past 5 years. Tell us it s name, where it was discovered, and what type of organism it is.
Road to the Six Kingdoms 2000 years ago Aristotle sorted organisms into two large groups: 1. Plantae- grouped according to reproductive parts and types of tissue. 2. Animalia- grouped based on movement- land, water or air
Ernst Haeckel (1866) proposed a third kingdom: 3. Protista- organisms that were neither plant or animal. When the microscope was invented, scientist learned more about structures and ways of life they came up with two more:
4. Fungi- mushrooms and moulds that obtain food through absorption. 5. Bacteria- call cells that lack a nucleus and other organelles. 6. Archaea- bacteria that live in very severe conditions, such as hot or acetic springs, or salt lakes have developed unique structures and mechanisms that allow them to survive there.
In what kingdom does each of these organisms belong?
Kingdom Animalia
Kingdom Fungi
Kingdom Protista
Kingdom Animalia
Kingdom Protista
Kingdom Protista
Kingdom Fungi
Kingdom Animalia
Kingdom Animalia
Kingdom Protista
Kingdom Bacteria
What are the Characteristics of Life? Living things are made of one or more cells. Must metabolize matter and energy. Interact with environment. Grow and develop Reproduce Adapt to surroundings
Three Domains of Life Kingdoms are grouped into three domains based on the types of cells the organisms in each kingdom have. 1. DOMAIN BACTERIA 2. DOMAIN ARCHAEA 3. DOMAIN EUKARYA (includes the rest of the kingdoms)
NAMING AND CLASSIFYING The practice of classifying organisms is known as TAXONOMY. All living organisms are classified into groups based on very basic, shared characteristics. Organisms within each group are then further divided into smaller groups. These smaller groups are based on more detailed similarities within each larger group.
This grouping system makes it easier for scientists to study certain groups of organisms. Characteristics such as appearance, reproduction, mobility, and functionality are just a few ways in which living organisms are grouped together.
Kingdom Phylum Class Order Family Genus Species
Taxonomy Each group in the hierarchy is called a TAXON. The more taxons two organisms share, the more closely related they are. Classification Rap- see YouTube!!!!
Example: See page 109, table 4.1
Classification of Humans Kingdom Phylum Class Order Family Genus Species Animalia Chordata Mammalia Primates Hominidae Homo Sapien
Classification Activity
Dichotomous Keys A dichotomous key is an identification key that uses a series of paired comparisons to sort organisms into smaller and smaller groups.
Two name system Today s two name system was developed by Swedish botanist, Carolus Linnaeus 300 yrs ago. Each species is given two names, the first represents the genus category and the second represents the species category. This is called BINOMIAL NOMENCLATURE.
BINOMIAL NOMENCLATURE Usually based on Latin or Greek words because these were the common languages of science at Linneaus time. Reflect characteristics of the organism or names to honour scientists.
Naming The first name indicates the genus. The first letter must be capitalized! The second name indicates the species. This is written in lower case letters. Both names must be italicized if typed, or underlined if hand-written.
Why not use common names? Common names can sometimes lead to confusion. Ex: Starfish- not a fish! Some common names have multiple meanings and some organisms have more than one common name!
Example: bakeapples, Rubus chamaemrus are also called cloudberries. Capsicum frutescens: what we may know as the green pepper is also referred to as a bell pepper, sweet pepper or mango depending on the place.
How do Scientists Classify Organisms? 1. Evidence from radioactive dating. Scientists infer how old a species is by dating fossils found in rocks. This is based on chemical isotopes found in rocks that decay at a certain rate.
Change in C14 over time
By analyzing the C14 remaining in a rock sample, the age of fossils in the rock can be determined. Fossils that appear in rock layers that are the same age are more closely related than those that are from different rocks that are much older or younger. The age and features of fossils can also indicate ancestral relationships between organisms as well.
2. Evidence from anatomy- Scientists look at similarities in bone structure to relate species. When the same bones appear in different taxon, it usually means they have a common ancestor. See picture, p.114
3. Evidence from Embryonic Development. Comparing early stages of embryonic development can reveal relationships.
Ex: Larval tunicates (sea squirts) have a notochord that is not seen in the adult stage. Because of this, they are classified with fish, reptiles and mammals in phylum Chordata.
4. Evidence from Biochemistry- Comparison of protein molecules among organisms can show genetic similarities. Ex: Studies of blood proteins in horseshoe crab revealed that it is more closely related to spiders than to crabs!
Phylogeny Phylogeny: the history of the evolution of a species or group, especially in reference to lines of descent and relationships among broad groups of organisms.
Branches on the tree indicate where species have evolved adaptations for better survival in their particular environment.
Cladistics: refers to a classification scheme that s based on phylogeny. It is based on the idea that each group of related species had one common ancestor, and organisms retain some ancestral characteristics and gain some unique derived characteristics as they evolve and diverge from the common ancestor. ( p.117)
Cladogram
Cladogram
Viruses Viruses have no cellular structure. They do not respire; they have no cytoplasm, organelles or cell membranes. Therefore they are NOT LIVING. What are they? Viruses are mobile genes that parasitize (attach to and destroy) cells.
Virus Structure Viruses consist of strands of RNA and DNA. surrounded by a protective protein coat called a CAPSID. The capsid protects the virus from attack by the host cell and helps the virus attach itself to the host.
Shapes: 1. Polyhedral
2. Retrovirus- circular
3. Rod shaped
4. Bacteriophage
Virus Assignment- Schoology
Representative Example: T4 Virus Reproduction One characteristic that viruses share with living things is the ability to multiply. Below is the life cycle of the T4 virus. This virus typically infects E Coli Bacteria.
T4 Bacteriophage