Today is Wednesday, October 23 rd, 2013 Pre-Class What does the Golgi Apparatus do? How about the...
-
Upload
rosalyn-stevens -
Category
Documents
-
view
215 -
download
1
Transcript of Today is Wednesday, October 23 rd, 2013 Pre-Class What does the Golgi Apparatus do? How about the...
Today is Wednesday,October 23rd, 2013
Pre-ClassWhat does the Golgi Apparatus do?
How about the lysosome?
http://classes.ansci.illinois.edu/ansc438/mamstructure/Golgi.GIF
You need a small bit o’ paper towel too. Just sayin’…
In This Lesson:Diversity and
Organization of Life
(Lesson 5 of 5)
Today’s Agenda
• That core assessment thing.• Another way to sort life.• Diversity and classification of life.• Body organization.
• Where is this in my book?– Academic: P. 190 and following…– Honors: P. 6 and following…
Endosymbiosis
• The topic of your coming core assessment is endosymbiosis. What’s that?
• Here’s a simplified picture:
http://endosymbiotichypothesis.files.wordpress.com/2010/09/endosymbiosis_c_la_784.jpg
Prokaryote
Prokaryote (with developing
nucleus)
The first eukaryote
Endosymbiosis
• If you need a reminder, both mitochondria and chloroplasts have a double membrane and their own DNA (which is not used for much) – unusual for an organelle.– They even have their own ribosomes!
• Scientists think this is evidence that mitochondria and chloroplasts were once free-living bacteria – living outside the cell.– In other words, mitochondria and chloroplasts were
once free-living prokaryotes (bacteria).
Endosymbiosis
• Then, as other organisms began to photosynthesize, levels of oxygen in the atmosphere rose dramatically.
• As a result, some prokaryotic cells (that could use the excess oxygen to produce energy for the cell) invaded others, later evolving to be mitochondria.
• Meanwhile the same thing occurred with the organisms that were photosynthesizing, with those prokaryotes evolving into chloroplasts.– The biological concept of one thing invading/taking-in
another is called endosymbiosis.
Endosymbiosis
• In short:– There are lots of bacteria on early Earth.– Oxygen levels rise considerably.– Small aerobic bacteria invade larger anaerobic bacteria
(which have nuclei developing) – endosymbiosis.– Together, along with the formation of the nucleus, the
eukaryotic cell evolves.– The smaller aerobic bacteria become today’s
mitochondria (with a similar process leading to chloroplasts).
Classifying Life
• Remember that classifying life is very difficult.• We went over the eight different
characteristics something must have to be considered alive.– There’s still room for “weirdness.”
• To start with, not even everything uses oxygen.– Aerobic: using oxygen– Anaerobic: not using oxygen
Carl Linnaeus
• Developed the system of classification we use (KPCOFGS) around 1735.
• Has since been revised to include Domain and now all sorts of other levels of classification.
http://gap.entclub.org/taxonomists/Linnaeus/Carolus_Linnaeus.jpg
The Diversity of Life
http://scepticon.files.wordpress.com/2009/02/phylogenetictreeoflife.jpg
PROKARYOTES
EUKARYOTES
Prokaryotes
• The vast majority of prokaryotes are unicellular.– They only have one cell.– For our purposes we will consider them all to be
unicellular.– And now, a photo gallery of some lovely
prokaryotes!
Eukaryotes
• Eukaryotes can be either unicellular or multicellular.– Remember, as long as it has a nucleus it’s a
eukaryote.• Like eu!
– Plants, animals, and fungi are all eukaryotic, along with a BUNCH of other stuff.
– Eukaryotes can look very different from one another.
– Eukaryote photo gallery!
The Diversity of Life
http://scepticon.files.wordpress.com/2009/02/phylogenetictreeoflife.jpg
PROKARYOTES
EUKARYOTES
Water Bear (micro-animal!)
http://thecontaminated.com/wp-content/uploads/2009/04/tardigrade-water-bear.jpg
Tree of Life
• There is an ambitious website called the Tree of Life Project.
• Its aim is to create a virtual tree of life connecting all known forms of life.– Kinda difficult. Just sayin’…
• Right now, you can trace a path from the roots of the tree (the broadest category of life) to the ends of the branches of the tree (the narrowest categories of life).
• You can also go from the roots all the way out to humans, and that’s your job for this little activity.
The Path from Our Roots
• Eukaryotes– Animals• Bilateria (animals with bilateral symmetry)
– Deuterostomia (animals that developed along a certain pattern)» Chordata (animals with backbones)
• Craniata (animals with skulls)• Vertebrata (animals with spines)
• Gnathostomata (vertebrates with jaws)• Sarcopterygii
The Path from Our Roots
• Sarcopterygii (Lobe-finned fish and land vertebrates)– Terrestrial vertebrates (land animals with
backbones)• Amniota (egg-based)
– Synapsida (mammals)» Therapsida (mammals)
• Mammalia (mammals)• Eutheria (placental mammals)
• Primates• Catarrhini (Humans, apes, Old-World
Monkeys)
The Path from Our Roots
• Catarrhini– Hominidae (humans, great apes) (brace
yourselves)• Homo (brace yourselves - humans)
– Homo sapiens
Levels of Organization
• In multicellular organisms, cells tend to become specialized as they grow.– They do different jobs.– Stem cells are not yet specialized, but can become
virtually any kind of cell – they can differentiate.• Between the cell and the complete organism
are several levels of organization.• Now it’s your turn to use the BioScale.
Levels of Organization
• Using your whiteboards (and partners), fill in the missing space in the BioScale below:– (Draw it in your notebooks too)
Organism
CellsOrganelles
Not to scale…
Moving upward from cells…
• A group of cells that has a common job is called a tissue.
• There are four major tissue types in the body:– Epithelial (linings and membranes, barriers)– Connective (structures and holds things)– Muscle– Nerve
Epithelial Tissue
http://www.stegen.k12.mo.us/tchrpges/sghs/ksulkowski/images/10_Simple_Squamous_Apical_Epithelial_Tissue.jpg
Connective Tissue
http://www.carlalbert.edu/dwann/tissue_images/connective%20tissue,%20loose,%20areolar.jpg
Muscular Tissue
http://2.bp.blogspot.com/_v2GFIISzHOU/R7lRf2YflXI/AAAAAAAAAC8/V9Qdc86FSrc/s400/Muscular%2BTissue.jpg
Levels of Organization
• Acting out the levels of organization– Class bonding!
• Some of you will be tissues.
Moving up from tissues…
• A group of at least two or more different types of tissues working together is called an organ.
• Examples of organs include:– Heart– Brain– Liver– Spleen– Stomach
Trivia Question!
• What’s the biggest organ in the body?– The skin.
• Your skin is your largest organ, and it has several different kinds of tissues in it:– Outside of skin (epidermis) – epithelial tissue.– Inside of skin (dermis) – connective tissue.• “Hey, your epidermis is showing!”
Levels of Organization
• Acting out the levels of organization– Class bonding!
• Some of you will be tissues.– Now those of you that were tissues were an organ
– the skin!
Moving up from organs…
• A group of at least two or more different types of organs working together is called…– An organ system!
• Examples of human organ systems include:– Nervous system (nerves)– Endocrine system (hormones)– Circulatory system (arteries, veins, capillaries)– Muscular System (muscles)
BioScaleOrganism
Organ SystemsOrgansTissues
CellsOrganelles
Organic MoleculesCompounds
AtomsSubatomic Particles
Levels of Organization
• Acting out the levels of organization– Class bonding!
• We will all be an organ system.– Some of us are epithelial tissue (epidermis)– Some of us are connective tissue (dermis)– Some of are adipose tissue (subcutaneous layer)
• With our powers combined, we become the integumentary system (your skin, hair, and other stuff).
Let’s have some closure…
• Draw in your notebook a diagram, pyramid, concept map, (whatever you want) that would represent how organisms, organ systems, organs, tissues, and cells all relate.– Here’s a start:
Organism