Mid-Year Course Evaluation (Dr. H's class only)

Please take some time over break to complete the following course survey for Dr. H's class.

Click here to take survey

Please be honest; the survey is completely anonymous, and the more honest you are, the better able I will be to modify the course/teaching techniques to help you.

Thanks, and enjoy your break.

Immune System via Zelda and FFXII (or XIII...I really don't know)

This is pretty much self-explanatory. And awesome.



As soon as I get some more time to poke around the Google results, I will post a few more...science-y ones. Till then, enjoy!

Brain Myths and Other Stuff

Some quick Google searching turned up a bunch of sites with the title "Top X Brain Myths Debunked", with X being anywhere between 10 - 12. Here are links to a couple that were brought up in class.

New wrinkles as you learn something

You only use 10% of your brain

If there are more that we talked about in class that you remember, you can link to them in the comments, or if you can't find anything, let me know and I will look them up.

Here is a link to a game where you can replicate the studies done in split brain patients. Remember, these are patients whose corpus callosum, the thick band of nerves that connects the left and right hemispheres of the cerebrum, has been surgically split to treat epilepsy.

What do I need to know for the test?

Major topics to review (by chapter)

Chapter 11

Local regulation vs paracrine signaling vs hormones
Stages of cell communication
Types of cell surface receptors
Second messengers - what are they, why are they used, examples (Ca⁺⁺, cAMP, IP₃)

Chapter 39

Tropisms (phototropism, gravitropism, thigmotropism)
Early experiments on phototropism (Darwin², Boysen-Jensen, Went
Ethylene = fruit ripening (thought I took this one off)
Short-day vs long-day plants
Red vs far-red light
Photoperiodism

Chapter 45

Hormones vs neurotransmitters vs local regulators
Hypothalamus relationship to ant. pituitary
Selectivity of responses to hormones
Insulin/glucagon system - know this in some detail

Photosynthesis

Respiration PowerPoint

Entropy and Time

Just saw this, and thought I would pass it along. Pretty good review of the second law of thermodynamics.

Favorite quote:

After all, you are a very highly ordered person, I'm assuming. If you are somehow a disordered homogeneous cloud of gas, then please accept my apologies.

I will try to get some more posts up here, maybe not the once-a-week pace of the summer, but something more regular. And maybe there will be some extra credit possible for "comment of the week" or something.

Chapter 7 PowerPoint

Here is the PowerPoint for chapter 7 with text.

Chapter 5 PowerPoint

Summer Assignment: 8.24.10

Malaria, Sea Grapes and Kidney Stones: A Tale of Parasites Lost

Ninja Bat Whispers to Sneak up on Moths

Two interesting posts about evolution this week, highlighting two interactions which drive much of evolution: parasitism and predator-prey. The first article is about a member of the Apicomplexan group. This group contains the human parasite Plasmodium which causes malaria. The particular research highlighted in the post details one particular Apicomplexan named Nephromyces which infects a tiny marine animal called the sea grape. Turns out, the Nephromyces my be protective for the sea grape against kidney stones. So it seems that this parasite and host have formed a mutualistic relationship - this means that they both derive benefits from the interaction. But the story doesn't stop there, as the researchers found a bacteria species living inside the protozoan which may help break down the kidney stones. So there may be two mutalistic relationships here, like some kind of biological Russian doll set.

The second article discusses the biological arms race that often occurs between predator and prey. Predator evolves some technique to hunt its prey...predator evolves a way to evade this hunting technique...predator evolves refined hunting technique...prey evolves refined escape technique...etc,etc. This is evident in many forms, such as camouflage or mimicry, and even seemingly simple adaptations such as fast running speed. In this particular case, moths which are hunted by bats using echolocation have evolved very sensitive ears to pick up the signals and avoid the bats. There is one species of bat, the barbastelle bat, which has evolved a countermeasure to the moth hearing (so a counter-countermeasure, I guess). The barbastelle bat is quiet. Very quiet. Turns out, if we could hear them, bats would be as loud as jackhammers. Little, furry, flying jackhammers that will bite you and give you rabies. I actually really like bats and am looking into enticing some to move into my backyard to help with a mosquito problem. Of course, if they were as loud as jackhammers, i would just keep covering myself in Off whenever I am out there for more than five minutes.

Whenever I hear people talk about how boring biology is, I always think about evolution research, which is constantly showing us that we really have no idea exactly how complex the world around us is.

Summer Assignment: 8.17.10

Bacteria Can Have a "Sense of Smell"

Not really all that surprising that bacteria can "smell," or simply detect airborne chemicals. Smell is directly related to taste, as anyone who has tried to eat their favorite meal with a cold can attest to. The only difference in smell and taste is how the chemicals are delivered to the receptors: direct contact for taste and airborne for smell.

The interesting part of the research, to me at least, was the fact that the bacteria respond to different "smells." Ammonia, for example, triggers the formation of a biofilm.

Biofilm is a major cause of infection on medical implants such as heart valves, artificial hips and even breast implants. Also known as 'biofouling' it costs the marine industry millions every year, slowing ships down and wasting precious fuel. But it also has its advantages. Certain biofilms thrive on petroleum oil and can be used to clean up an oil spill.

Algebra and Circuit Breakers
Lots of great points in this post about the current state of math and science education/knowledge. There is a general lack of understanding about math and science in the general public, and I do not just mean that people don't know what DNA stands for, of how to factor a polynomial. It is more important to understand math and science as processes, ways of thinking about and solving a problem, rather than a set of facts to be memorized. I think that this is very nicely illustrated in the linked post by the story of the circuit breakers.

How often do we hear people say "Oh, I'm not a math person, you figure out what the tip should be for lunch"...what if someone said "Oh, I'm not much of a reading person, you tell me what the menu says." Those two statements are really not that different, yet one is OK, and the other signifies a breakdown in the educational system. Why is that? Why is it socially acceptable (and in some cases preferable) to be "not a math/science person" while not being a language person is unheard of. Not knowing how to critically think, weigh evidence and draw a logical, evidence-based conclusion is as integral to math and science education as knowing the difference between verbs and nouns are to language education.

And don't tell me that basic reading is a fundamental life skill while finding percentages is not. The current economic situation has been partly blamed on people's misunderstanding of basic math. And anyway, my point is not about math and science factual knowledge, but using the skills gained in studying them to navigate life.

[The] skills you learn in math go well beyond learning to plug numbers into the quadratic formula. Math is about systematic thinking, and systematic thinking is what built human civilization. Without the ability to think systematically, we'd all be stuck huddling in caves, hoping the lions didn't eat too many of us tonight.

And yes, I am treating math and science as one here, as the author of the post does. One of the other major problems with education is the compartmentalization of learning. This isn't math class, why are we talking about numbers? This is [class x] not [class y], why are we talking about [topic from class x]??? Because everything is connected, and seeing those connections is the hallmark of an educated mind.

Hopefully, if I have done my job as an educator, after taking AP Biology, you will begin to see and appreciate those connections.

Summer Assignment: 8.10.10

Pees and Carrots

Sustainable fertilizer may be easier than we think. This is actually a much bigger issue than it seems, since the current practice of using fossil fuels to create fertilizers for industrial farming means that we use 10 Calories of energy for every 1 Calorie of food produced. This is obviously not a sustainable practice for very long. The question is though, will people be willing to pee on their salads before eating them?

Using Blue Whales' Perfect Pitch to Drive People Insane

FINALLY!! Biology has a mad scientist. Too long only chemists and physicists were allowed to hatch mad schemes to take over the world.

I have only to gather a pod of blue whales in the harbor of some Pacific coastal town and make them direct their song landward. The synchronized infrasonic hum, deafening yet inaudible, has the potential to cause anything from high blood pressure to incipient madness in the townspeople. At the very least, it'll produce a hum that some people can hear and others can't, which would be unbearably annoying.

Summer Assignment: 8.3.10

More links than usual this week, each one to a slightly longer article...but they are all about sex!















[Image: mating sand wasps, Alex Wild]


Gonna Have a Fungal Good Time

When Love Shocks

Water Strider Blues

Darwin, Sex and Dada

I don't have much to say about these posts, just pick one or two to read over and let us all know what you found interesting.

Summer Assignment: 7.27.10

How Key Enzyme Repairs Sun-Damaged DNA

Maybe the first step in a sunscreen/sun burn lotion that heals DNA mutations. Though in the past, the trip from gene to marketable treatment has been very long.

World's Largest Rat Discovered

13 pound rats? Yeah, I am glad they are extinct.

Comic-Con: Zombies in the Eye of the Beholder

There are two very discreet types of zombies - fast (I am Legend, 28 Days Later) and slow (Zombieland, Night of the Living Dead). It seems rare that someone will enjoy zombies from both sides of the fence.

Summer Assignment: 7.20.10

Great comments last weeks, Keep them coming. Be sure to read other students comments as well as the post. You can also get points for responding to/commenting on a student comment as well as the linked articles.

Only one link this week, because it is a longer article, so the other two I had for this week about why high-heeled shoes are bad and shrimp on Prozac will wait till next week.

How Microbes Defend and Define Us

AN article about my favorite gross-out medical procedure - fecal transplant.

Dr. Khoruts mixed a small sample of her husband’s stool with saline solution and delivered it into her colon. Writing in the Journal of Clinical Gastroenterology last month, Dr. Khoruts and his colleagues reported that her diarrhea vanished in a day. Her Clostridium difficile infection disappeared as well and has not returned since.

It's not really completely about that, it is more about recent advances in our understanding of the bacteria that live in and on our body. Bacterial cells outnumber human cells by about 10 to 1, and scientists are just beginning to understand the roles they play. Current research highlighted here using DNA sequence analysis is uncovering a surprising amount of uniqueness to each person's bacterial load. Each "environment" on the human body has its own set of microbes, and each person may have all or part of the population.

There is even variability within one person:

Only 17 percent of the species living on one person’s left hand also live on the right one.

That number is very interesting, just based on the number of times our right and left hands come in contact. (As I read that sentence, I noticed that my hands were on top of each other and immediately moved them away from each other. Didn't want right-hand-bacteria on my left hand, I guess.)

The article also goes into current evidence for a link between microbe exposure as a baby and health later in life.

[M]any diseases are accompanied by dramatic changes in the makeup of our inner ecosystems. The Imperial College team that discovered microbes in the lungs, for example, also discovered that people with asthma have a different collection of microbes than healthy people.

All of this research may be leading to potential new treatment options for many diseases: the use of probiotics, or helpful bacteria. Just not the ones found in a container of yogurt. Those "probiotics" don't really do much for you.

I am going to stop here, before this becomes a skepticism/critical thinking/evidence-based decision making post. I am sure there will be at least one of those this summer.

Summer Assignment: 7.13.10

Hello and welcome to the official start of the AP Biology Summer Assignment. I know that I told most of you that the first post would be up last week, but a number of factors made it impossible for me to get anything up here. This will be the first post that you can earn points for, and from now until the end of the summer, they should be up once a week. Your comments will be moderated, which means that I will read them first before they show up on the blog, so don't worry if your comment does not show up immediately, it just means that I am not at the computer and have not read through all the comments yet.

Any questions or concerns can be emailed to me, or posted in the comments. On to the links for the week...

The proton shrinks in size

Not exactly biology-related, and it is only 0.00000000000003 millimeters, but that is a 4% difference, and any change in one of the three basic particles of an atom should be pretty big news.

Pohl and his team have a come up with a smaller number by using a cousin of the electron, known as the muon. Muons are about 200 times heavier than electrons, making them more sensitive to the proton's size. To measure the proton radius using the muon, Pohl and his colleagues fired muons from a particle accelerator at a cloud of hydrogen. Hydrogen nuclei each consist of a single proton, orbited by an electron. Sometimes a muon replaces an electron and orbits around a proton. Using lasers, the team measured relevant muonic energy levels with extremely high accuracy and found that the proton was around 4% smaller than previously thought.

Could be something to keep track of...though one researcher quoted in the story does seem to think that this new result could also be an error.


"Sinister Motion" may influence soccer referees

Or, just an excuse to post something about the World Cup. Once again, the third-place match ended up being much more entertaining than the final. The Dutch obviously knew they had to play physical to counter Spain's offensive capabilities. They seemed willing to take as many yellow cards as they needed to get the game to penalty kicks..,not sure it was the best strategy, and I'm still not sure why this was not given a straight red.



Why you should never arm wrestle a saber-tooth tiger.

To be honest, I only clicked through to this story because of the headline, but it is fairly interesting. Because of their oval-shaped cross section, saber-tooth cats had relatively weaker canine teeth than do modern cats, who have conical-shaped teeth. This was made up for by their stronger forelimbs.

Despite their vulnerable canines, prominent muscle attachment scars on sabertooth limb bones suggest the cat was powerfully built. Saber-toothed cats may have used their muscular arms to immobilize prey and protect their teeth from fracture, she explained.