UNIT TWO, DAY 6
AP BIO
11/5/14
OPENER
• Complete the survey found here:
• http://goo.gl/CiU6sH
• You have 10 minutes. If you need a device, come
get an iPad
• Also: take out your HW to turn in.
AGENDA
• Mini-Lecture: What all Life Shares
• New LT
• Starting point for speciation. . .
• Introduction to Speciation
• New LT
• What is a Species?
• How do new species arise?
• Pair Work:
• Reproductive Barriers
• Gallery Walk: Reproductive Barriers
NEW LT #1
• I can identify and describe processes and features
shared by all life, and explain how these processes
and features support the idea of common ancestry
for all organisms
• Quick blast of info: this mini-lecture, and the video
on the website. That’s it.
THE DOMAINS OF LIFE
• All living things can be divided into three groups,
called DOMAINS.
Common
Ancestor
Bacteria
Archaea
Eukarya
COMMON FEATURES OF ALL THREE
DOMAINS
• The Code of Life
• DNA/RNA as carriers of
genetic information
• DNA bases: A, T, C and G
• RNA bases: A, U, C and G
• Universal Genetic
Code:
• Base order=information
stored in DNA/RNA
• What the order “means”
is always the same
COMMON FEATURES, CONT.
• The Central Dogma of Molecular Biology:
• Transcription:
• Information in DNA copied into RNA
• Translation:
• RNA information used to make a protein
• Ribosomes—found in ALL cells
• Traits: ALL of our traits, visible or not, are in some way
determined by a protein
COMMON FEATURES, CONT.
• Shared Metabolic Pathways:
• A metabolic pathway is a series of chemical reactions
• Purposes: producing energy, making something, breaking
something down
• Photosynthesis
• Synthesis of sugars using light energy
• Cellular Respiration:
• Glycolysis: extracting energy from glucose (simple sugar)
• Energy carrier:
• Adenosine Triphosphate: ATP
WHAT DOES THIS TELL US?
• ALL life shares a common ancestor with these traits:
• DNA/RNA based genetics
• Central Dogma
• Simple metabolic pathways/ATP
• If this WASN’T true, what would we see?
• Different strategies, in different life forms, for:
• Storing genetic info
• Turning that info into traits
• Getting energy
• THERE ARE NO ALTERNATIVE STRATEGIES IN DIFFERENT
FORMS OF LIFE.
BREAK
NEW LT #2
• I can explain the mechanisms of speciation
• Supporting targets:
• I can define the biological species concept
• I can describe the importance of reproductive barriers in
speciation
• I can distinguish between pre and post-zygotic
reproductive barriers
• I can identify and describe the seven types of reproductive
barriers
• I can give example of speciation that resulted from each
type of barrier
SPECIATION
• The Biological Species Concept:
• Defines a species as a group of organisms that can will
breed and produce offspring in nature
• Speciation: an evolutionary process that produces
one or more new species from an existing species
• What conditions lead to speciation?
• Reproductive Isolation: some barrier that prevents members
of a population of the same species from breeding
• Evolution
• Two kinds of barriers:
• Pre-zygotic: prevents mating, or formation of a zygote
• Post-zygotic: mating happens, offspring no ok
SPECIATION, VISUALLY
NEED 4 AT A TABLE/TWO AT
SMALL TABLE
MAKE IT HAPPEN SCIENTISTS!!
MINI-POSTER
TYPES OF BARRIERS
1.
2.
3.
4.
5.
6.
7.
Habitat Isolation
Temporal Isolation
Mechanical Isolation
Behavioral Isolation
Reduced Hybrid Viability
Reduced Hybrid Fertility
Hybrid Breakdown
Do: Work with a partner
to complete the miniposter assignment
Use: Book (Section 24.1),
Internet
Time: 30 minutes
Finish early: start (or finish)
your homework.
GALLERY WALK
• The posters made by your classmates will provide
you with information about the different types of
reproductive barriers.
• Task:
• Move to each table, look at poster
• Take notes
• If you have a question, write it on a sticky note and stick in
on the poster
• Rotate after three minutes
• You need to know ALL of these.
HW
• New wrinkle:
• ASKING QUESTIONS is now part of your HW
• Questions you generate will be (hopefully) ANSWERED in
class
• If I use/answer your question=extra credit in 20% grade