Blogging My Biology Class 20080822

Biology, Eighth Edition, by Campbell & Reece, et al.

Biology, Eighth Edition, by Campbell & Reece, et al.

My notes and thoughts from Biology 111, for Friday, August 22, 2008. The entire series can be found here.

This morning’s lecture was teh awesome.

Doc started with some announcements, a reminder to get a composition book and a folder for lab, and a reminder about the Science Club. There is a 2hr canoe paddle on the New River and a shore clean up thing on September the 6th. After my English class I stopped by the Doc’s office and gave him the $2 for membership, though obviously I can’t do the canoe thing, for physical reasons. If I’m free that day, I may see if I can just meet the club at the clean-up site.

Does membership in the Science Club make me an official Science Geek now? I mean, I’ve even paid the dues and all! I’d like to be part of the Official Science Geek Club. I mean, that’s part of the benefits package, right? Plus, Science Geeks have the hottest chic … uh… I mean that means nothing to me because I’m married.

Ok, on to the lecture, y’all quit distracting me with the pleasures and temptations of the flesh:

(Continued Below the Fold)

Doc started out by going over the levels of biological organization that we ended with on Wednesday, and laid out that we’d be covering the bottom levels mostly in Bio 111, and why. Seeing as how you have to understand the basics of the building blocks before you can really start to understand the higher levels, it makes sense that we’re going to be spending our time at the levels of cells and their constituent parts (molecules, atoms, subatomic particles). We’ll be skipping up to the Population level in the last unit of the course.

Bio 112 will focus on the upper levels.

For anyone not familiar who might be reading this, here’s what we’re talking about, from the top level down. Each level consists of members of the next lower level. It’s pretty straightforward.

Biosphere
…..Ecosystems
….. …..Communities
….. ….. …..Populations
….. ….. ….. …..Organisms
….. ….. ….. ….. …..Organ Systems
….. ….. ….. ….. ….. …..Organs
….. ….. ….. ….. ….. ….. …..Tissues
….. ….. ….. ….. ….. ….. ….. …..Cells
———————————————-
….. ….. ….. ….. ….. ….. ….. ….. …..Molecules
….. ….. ….. ….. ….. ….. ….. ….. ….. …..Atoms
….. ….. ….. ….. ….. ….. ….. ….. ….. ….. …..Subatomic Particles

So doc drew a analogy between Bio 111 and the foundation of a house. It takes months to put in the foundation, and it’s critical to get it right, because the rest of the house, while quick and easy to put up in comparison, requires a good foundation.

So, why are we dealing with cells?

“]Salmonella typhimurium by AJC1 @ Flickr

Color-enhanced scanning electron micrograph showing Salmonella typhimurium (red) invading cultured human cells. Credit: Rocky Mountain Laboratories, NIAID, NIH

Cells are the basic structural and functional units of life.

Structural —-> All living things are made up of cells
Functional —> All the Unity of Life functions occur at the cellular level

So then he posed the question of why are cells alive and why are their constituent parts (molecules) not alive? (Hence the line in the organization level diagram above.)

Emergent Properties

The properties of a level of biological organization not present in lower levels, resulting from the interactions of their constituent parts. Emergent Properties are in most cases unexpected, and not predicted from knowledge of the properties of the lower level parts.

EX 1: Water
Water is made up of hydrogen and oxygen, two flammable gases
But water, as a result of the interaction of hydrogen and oxygen is a non-flammable liquid (at room temperatures)

EX 2: Sodium Chloride
Sodium is a highly reactive explosive silvery metal
Chlorine is a toxic gas
Table salt is vitally necessary for life

EX 3: Tree
Carbon Dioxide gas and liquid water interact to form a 500 kilo tree.

(Note: The question was posed by Doc: “Where does a seed get all the stuff to make a tree?” I was surprised that I’d never really thought about where the wood comes from. Obviously not the soil, as Doc pointed out, or the tree would be in the middle of a big hole. Where does all that stuff come from? CO2 and water.)

So then we came back to The Diversity and Unity of Life

Signature of Charles Darwin from Wikimedia Commons

Signature of Charles Darwin from Wikimedia Commons

1859 (I wanted to yell out the significance of this date when he wrote it on the board and left it hanging there all alone.)

On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, by Charles Darwin

Doc talked about Darwin’s voyage on the Beagle briefly, then dove in head first. (As an aside, I kept an ear out for groans or clucking tongues, but didn’t notice anything untoward.)

Descent with Modification

–All organisms are related by descent from a common ancestor —> explains the unity of life.

–Populations change over time as they adapt to new or changing environments through the process of Natural Selection —> explains the diversity of life.

“Descent with Modification is the only idea that explains both of these characteristics of life.”

Doc then put up a table regarding generations of our ancestries:

Generation – Ancestors
1 ….. ….. ….. ….. 2 <—– 6,000,000,000 people on earth now
2 ….. ….. ….. ….. 4
3 ….. ….. ….. ….. 8
4 ….. ….. ….. ….. 16
5 ….. ….. ….. ….. 32
6 ….. ….. ….. ….. 64
7 ….. ….. ….. ….. 128
8 ….. ….. ….. ….. 256
9 ….. ….. ….. ….. 512
10….. ….. ….. ….. 1024

So the question was, “why were there fewer people on earth two hundred years ago (about generation 10) than there are now? Why weren’t there 1024 * 6B?”

The answer of course is that we share ancestors. There were some ooos and aaaas at the impact of the numbers when it dawned on people that 1024 people were in their family tree in one generation just 200 years ago. I’m the family armchair genealogist, so I had that moment years ago, but I remember it well.

To illustrate Descent with Modification, Doc drew a graph similar to the following:

Extant Species

and explained that each red dot was a species.

Then he filled in the ancestry tree thus:

Heredity Tree

Then he boxed in all the extant species, and explained that the reason that all life have cells and DNA and metabolism is because of heredity from the common ancestor.

Heredity From a Common Ancestor

And then explained that DNA replication is not perfect, and that errors occur and adaptation to the environment takes advantage of that to produce speciation:

Descent with Modification

So if a line of heredity develops trait X, its descendants will have trait X, and if another line develops trait Q, its descendants will have trait Q.

The lecture was straightforward and easy to follow, I imagine even for someone who doesn’t hang around a bunch of Science Geeks. Good day, for sure.

From whence came the art:

The first image is of our textbook, Biology, Eighth Edition, by Campbell & Reese et al.

The image of the electron micrograph is titled Salmonella typhimurium, uploaded by AJC1, Original Credit: Rocky Mountain Laboratories, NIAID, NIH.

The image of Charles Darwin’s signature is from Wikimedia Commons and is licensed under the GNU Free Documentation License.

All graph images are created by me, and licensed under the Creative Commons Attribution-Noncommercial-Share Alike 2.0 license. They are clickable for larger versions at my Flickr page.

7 Responses to “Blogging My Biology Class 20080822”

  1. Lou FCD Says:

    I’ve submitted this post to this week’s Tangled Bank

  2. Beth Says:

    Lou, are you familiar with BioEd OnLine?

    (am hoping my html works and that that doesn’t come out garbled!)

    Anyway, it’s a biology teacher/student resource site. I highly recommend it.

  3. Lou FCD Says:

    Thank you Beth. Your link works fine.

  4. biancs Says:

    I wonder if he will go over the 20 year study of E-COLI where over 40,000 generations several lines developed the ability to metabolize citrate. Oh and it is about time you de-redneckified yourself with a proper haircut.

  5. Lou FCD Says:

    I’m sure it’ll be mentioned along the way, biancs. I’d been reading about that, and it’s frackin’ amazing.

    It’s a really nice example of descent with modification.

  6. Blogging My Biology Class 20080825 « Crowded Head, Cozy Bed Says:

    […] We began Monday’s lecture where we left off on Friday (which is always a good place to start). Doc put the tree of life back up on the white board, and we did a quick review of what we went over on Friday regarding inheritance and emergence. […]

  7. Tangled Bank #112 « Science Notes Says:

    […] Lou, FCD says I’ve decided to blog my Biology 111 class, which began Monday this past week. Here’s one of the better episodes: ” Blogging biology class.” […]


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