Crunch Time

[caption id="attachment_927" align="alignleft" width="300"] By Ano Lobb. @healthyrx[/caption]

The title fits this post in so many ways. First, this edition of the week in review covers two weeks of material (9/24-10/5). Second, It includes all of the students who had not made a submission to the weekly reporter. That means this edition contains five distinct contributions. Finally, you are privy to an excellent account of all of the stress everyone endured while finishing up their INCREDIBLE genetics projects. The students have so much to offer that I am just going to go ahead and shut up. This week you can thank Shiyan Shoyoye, Yaa Ofori Marfoh, Kaliah McGirt, Jarrett Bumidang, and Niya Carrington for their contributions.



Shiyan Begins:

This week in AP Bio was definitely an  experience! It was crunch time before our genetic disease campaigns were due, and I’m sure everyone in the class was trying to finish up presentations and campaigns. Fortunately for us, Mr. Kite allowed us to take any extra time we had in class to do so.

Besides our scrambling to do a project that we’ve had weeks to execute, a major factor in our week was our intro into Genetics. The Cell Cycle tracks the life of a cell all the way from the time it divides until it gets to what appears to be full circle and divides (AGAIN!). We also learned that mitosis is similar to a xerox machine because one cell enters, and two identical cells come out. Mitosis occurs in essentially all somatic cells EXCEPT gametes. We were given a great mnemonic to remember the steps in Mitosis: IPMAT-C!

What regulates all of these steps that go into the cell cycle and mitosis?

WEEEELLLL, there are “checkpoints” that cells must pass before they are allowed to go into the next cycle, and these gates represent quality control. If there’s something wrong with the cell, then the cell goes to phase G0 until the problem’s been fixed. If it’s too far gone, well, you know the deal… Cyclin-dependent kinase, a protein found inside of a cell, allows the cell to progress in the cell cycle (or in other words, grow) when it binds to M-cyclin. Sometimes, cells can tell when it’s not a great idea to divide. For example, if microtubules don’t bind to the kinetochore during anaphase, that signals the cell to stop growing. Cells also stop growth when they have filled a specific area.

When cells lose control, it means that one form of the cycle has gone awry, whether a broken DNA reproduces, or a faulty somatic cell continuously divided. This creates cancerous cells that are either benign (mild, not cancerous), or malignant [cancerous tumor(s)].

Yaa Continues: 

During the week of September 24, the students in Lab 207 had one main goal: Getting their genetic disorder projects completed in time to present. Though we took notes and had class, we students spent majority of the week stressing about approaching the deadline of our quarterly projects–Mr. Kite’s constant reminder of this deadline was like a ticking time bomb for me. This stressing consisted of extremely late nights working without sleep, venting and complaining to each other, and bragging about our ideas and intentions for our projects (this was done by the lucky few who managed to finish early and relax for the rest of the week). Working on our projects aside, the week in class also focused on some new topics: cell signalling, and an introduction to cell division with the cell cycle and mitosis.

Monday’s class began with Mr. Kite’s declaration that we’d be conducting an experiment to introduce us to cell signalling. In the experiment, we were to use 2-types of yeast alpha and “a” and monitor how they reproduced (then i’m guessing we were going to link our observations to cell signaling). However, to our dismay, many of our experiments yielded no concrete results that would help us understand this new concept because we could hardly see the yeast cells. My group in particular had trouble discerning air bubbles from the yeast cells we were supposed to locate. But no matter, with Mr. Kite’s help we did find some (and we were able to at least show our other classmates what we were all trying to find). So although the experiment did not go as well as planned, it served as a pretty decent introduction to cell signalling.

As the rest of the week followed, we learned about the cell cycle which is basically the life of a cell from the time its first formed (from a parent cell) to the time it divides into two daughter cells. We learned about the two main phases of the cycle: Interphase and M-phase which is Mitosis. Mitosis consists of 5 steps and is the way plant and animal cells multiply. In mitosis, 2 exact copies of a parent cell are formed. After making sure the steps of Mitosis was drilled into each and everyone of our heads, we moved on to ways in which the cell cycle is controlled (“checkpoints” to maintain order) and how that control may be hindered (continuous growing, leading to cancer). Lastly, we learned about the Alternation of Generations which is basically the processes an organism uses to maintain a consistent number of chromosomes. They alternate between diploid and haploid. We rounded up the alternation of generations concept with one main lesson: Mitosis produces exact copies of cells (the organism gets bigger and its cells go from haploid to diploid, while meiosis cuts genetic material in half (diploid to haploid).

At last the week came to an end with the moment we all waited for: Project Presentations. I must say, I had no idea why my fellow classmates were practically pulling their hair out over their projects; they were presented wonderfully. From podcasts, to model PSAs and documentary trailers, we were all experts on our topics and we created exceptional awareness campaigns. I think its safe to say we left Mr. Kite incredibly proud and in awe of how far we went with the requirements he gave us. In fact, we were all in awe of each others projects. Though we were all nervous about our projects, I must say, our sleep deprived nights did our projects some good. They were just brilliant!

Well this brings my report of the past week to an end. Thanks for reading!

Kaliah Adds:

This week in biology we talked about the cell cycle, mitosis, and we put the finishing touches on our genetics projects. The cell cycle tracks the life of a cell as it divides. Mitosis which is a part of the cell cycle and is like a copier because one cell enters and two identical daughter cells come out. We also talked about local and long distance signaling. Local signaling is when one cell is close to the cell and is activated which activates it’s neighbor cell but when the next cell is activated the other cell is  turned off to save energy. Long distance signaling is the same concept but the cells aren’t right next to each other they are a good ways away.

Jarrett Contributes:

The week of September 24th was quiet eventful. We reviewed cell signaling, a topic we learned the week before, and took a quiz to test our comprehension of the topic. We also learned about mitosis, the process of reproducing our own cells with the same exact set of DNA. In order to further understand and ensure our comprehension of the topic, the class was broken into groups and was instructed to build models of the process. After learning what mitosis was, we discussed HeLa cells. HeLa cells, as we learned in class, originated from Henrietta Lack’s tumor on her cervix. The cells continued to reproduce and essentially “never died.” These cells are important to science and research, but we were told to go in groups to discuss and choose what we believed was the significance of HeLa cells. Finally, we closed the week by presenting our quarter projects. Throughout the entire week, most students had been stressed and worried for this day. We were granted time in class throughout the week to work on our projects. Each group presented their projects to help the class understand, learn more about, and raise awareness for a specific genetic disorder of their choosing. Each group succeeded in surpassing expectations and produced products that were beyond the thinkable. The class left for the weekend stress-free and relaxed, looking forward to the weekend.

Niya Concludes:

This week in AP Biology we learned about the meiosis process and how it differsfrom mitosis. We built models of the meiosis cycle and helped each other to understandwhat happens during meiosis and the products that we get from meiosis. We got theunderstanding of crossing over and the different ways that daughter cells vary with thedifferent strands of DNA. We also got to split up into groups and learn about MRSA andthe effects that it has on the environment with the improper disposal and the over use ofantibiotics that is causing organisms to become resistant to it. In the groups we got toidentify the problem, think of things that contributed to this problem, and ways that wecould decrease the issue.To review over the video “Mendel and His Laws” we broke up into groups andeach group took a section of slides from a PowerPoint to thoroughly explain to the classhow Mendel came up with his theories and the work he did with the pea plants. The classlearned about the crossing over of genetic information and how Mendel could use thedominant and recessive alleles to figure out what traits the offspring from each generationwould inherit. This class discussion helped majority of the class to understand Mendel’swork better.This week we had to learn how to multiply and add alleles together to get thepercentage of the possible genotypes for each offspring. A long with this we used thepunnett squares to help us determine the genotypes. Even though this was a littlechallenging for some at the end of the class period pretty much everybody got the hang ofit. On the last day of the week we just reviewed over the video “Complex Inheritance”and talked about our new vocabulary. After that we were allowed to work on unfinishedclass work for the end of the nine weeks.

This is undoubtedly the longest blog post I have put up. If you've made it thus far I salute you. Thanks for reading!