Week 29
2/26-3/1
Agenda 2/26
HW - Descent with Modification Assessment Thurs, 2/29
Homology Lab
Agenda 2/27
HW - Descent with Modification Assessment Thurs, 2/29
Homology Lab Debrief: Discuss & Record
Relationships Visible in Homology
See Canvas for slide deck (make a copy and share with your group)
Get one notes paper per person in your group!
Break
Beginning Target (1) | Approaching Target (2) | Meeting Target (3) | Exceeding Target (4) |
Student identifies the incorrect common ancestor with flawed or invalid reasoning. Incorrect order of species AND flawed reasoning. OR incorrect order but reasoning may have some accuracy (similarities are correct, but doesn’t know how to identify them/explain them). | Student identifies correct species as common ancestor BUT with incorrect, flawed or invalid reasoning. Identifies the next species most similar to common ancestor with no reason given. And same for the remaining species. Correct order, but invalid, flawed, or incorrect reasoning. | Student identifies correct species is the oldest based on the most number of sequence differences from the other species OR it being the oldest. Identifies the next species because it has only one change in the second codon, OR is the second oldest fossil. Third species is next, and has three changes from the common ancestor. Other 3 species are the youngest because they are most different from the common ancestor, but two are more closely related. | Student identifies correct species (Ant) is the oldest based on the most number of sequence differences from the other species AND it being the oldest. Identifies the next species (Fly) because it has only one change in the fourth codon, AND is the second oldest fossil. Third species (Frog) is next, and has three changes from the common ancestor. Two of the species remaining are more related (Bat and Whale) and are the youngest because they are most different from the common ancestor. They have the same change in the sixth nucleotide (GCG becomes GCC), so they are more closely related to each other than to the youngest species (Human). |
Summative Assessment
Please put your phone in phone holder on DND, airplane or off.
Desks into rows.
Need a pencil/eraser.
Hold on to test, do not turn in.
Agenda 2/29
HW - None
We need to talk about where you and I and all that other life out there came from.
Unit’s gonna have 2 parts:
Quick notes (30min, tops)
Come up and grab and glue into notebook
All about where all that life that evolves comes about
Cells! The smallest unit of life.
A cell is a self-contained living thing.
Contains DNA
Performs metabolism
Does reproduction
DNA’s job:
Instruction book
What a cell looks like and does is pre-written
Metabolism:
Moving, getting and storing Energy, keeping stable
Reproduction:
Make (a) descendent(s)
Pop quiz:
What biomolecule determines how / if a cell can reproduce and do cellular respiration?
Pop quiz:
What biomolecule determines how / if a cell can reproduce and do cellular respiration?
DNA encodes everything
Some living things are only made of one cell
E.g. this is an amoeba - one cell!
E.g. this is slime mold - ditto!
The living things you know of are made of multiple cells - multicellular
Humans:
Males have ~36 trillion
Females have ~28 trillion
Brains have ~80 billion (~0.3%)
Every single one of those cells…
Contains DNA (in a nucleus)
Performs metabolism (like respiration)
Performs reproduction
Question: are all the cells in the hooman the same?
?????
Question: are all the cells in the hooman the same?
No - different cells have different shapes, functions, abilities…
BUT
You’ve all likely seen images like this, that this is what cells look like.
It’s a lie.
Cells don’t look like this.
BUT
It’s a useful reference point.
Let’s sketch out a fake cell in your body real fast.
Nucleus w/ DNA
Mitochondria
Cytoplasm
II. Reproduction: Cloning Life
What do you cells and bacteria have in common when it comes to reproduction?
Cloning.
Cloning is all about making a copy
A cell will copy its DNA, copy what is inside of its cytoplasm, and split in two
Congratulations - you have two copies of the same* cell
Why clone cells?
Because it works and it’s FAST.
If you survive, that means nature hasn’t selected against you.
So why not make a copy of your wonderful, successful self?
Why clone cells?
Because it lets you become multicellular and complicated.
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Seems rational.
Is there any downside to this way of reproducing?
Seems rational.
Is there any downside to this way of reproducing?
Yeah - you might work now, but if the environment changes, your bebe’s bebes x.x
III. Sex
Recently evolved about a billion years ago.
Instead of cloning cells to make a descendent…
You combine two sex cells.
They develop into your descendent.
How’s it work?
Each sex cell only has HALF its parent’s DNA.
The offspring will have a UNIQUE combination of DNA.
Question:
How does sexual reproduction help solve cloning’s problem?
Seems rational.
How does sexual reproduction help solve cloning’s problem?
If every bebe is different, there’s a chance SOMETHING will have DNA & traits that let it survive
These notes are introductory
We’re going to explore all of this in more detail between now and spring break.
But first.
Why do cells divide?
Cellular Division
Diagram together
Amoeba Sisters - Cell Cycle (9:19)