Roundup: Genetics and Review

Finals are next week (it’s crazy how fast the semester has gone!) and the AP Bio team has been working hard at finishing up our genetics unit and beginning review. We jumped right in after a relaxing Thanksgiving break with a class discussion about Cracking the Code of Life, a PBS documentary we watched about the progress we have made in genetic research. The movie talked a lot about the human genome project, which was an effort to map the entire human genome using new technology. Instead of talking only about the science of genetics, we got more into ethics and our opinions about DNA technology. We came up with some discussion questions to guide our talk, they were:

·     1) Is it possible/ethical that the U.S. would ever have a DNA database of citizens available to doctors or researchers?

·     2) Is it smart to genetically test people- should the president be tested? Do we want to and should we know if others or we have a disorder?

·     3) If parents could choose a child’s DNA, what would be the social consequences?

Each of us wrote blog posts about our thoughts on the film – here’s what Bharathi had to say on the prospect of parents choosing their child’s DNA:

"There has been a lot of controversy on this subject. I believe that parents should not be able to choose their baby’s DNA because it will make everyone perfect. The world is based on imperfections and imperfections are what create diversity and uniqueness in our lives." 

Abi shared her thoughts on the ethics of DNA technology, speaking about the medical records in Iceland, which were public to researchers:

“…There is an ethical issue with as to whether the family history from everyone was appropriate to release to the public. Personally, I think that if the DNA can help scientists figure out how genetic illnesses work, looking at an entire population’s DNA is acceptable.”

Finally, Shauna shared her opinion on whether she would like to know about possible genetic disorders:

"If there was a chance I could have a gene such as a cancer gene, I would want to know in order to do what I could to prevent it. I think it is better to know and be prepared than for it to just happen.” 

Whether we want to know all of this new genetic information or not, advancement in DNA technology is happening! This became clear later in the week, when we split up into groups and researched emerging DNA technology in fields such as medicine, pharmaceuticals, forensics, the environment, and agriculture. The presentations were very interesting – I had no idea of the breadth of subjects that DNA could be applied to, and I had no idea of the number of technological advancements that have been made recently. The information in our genome has the power to cure diseases, congeal copper, catch criminals, and even yummier cucumbers! One of the most interesting tidbits I learned was during the agriculture presentation, when Simran shared that researchers at UC Davis have found a way to genetically engineer and “domesticate” wild cucumbers. When each of 9 genes in the cucumber is turned off, the bitter taste characteristic of wild cucumbers disappears.

This past week, we focused on our genetics symposium, where individuals and small groups delved into various genetic disorders. We learned about the internal, external, psychological and biochemical characteristics of everything from Celiac disease (which affects about 1 in 100 people) to Progeria (which affects 1 in 3-5 million). Since genetics encompasses so many other topics that we have studied, our genetics symposium ended being a great review of things like cell signaling, cell structure, and meiosis/mitosis.  Both Amanda’s Voicethread (on Angelman’s Syndrome) and Rebecca’s Voicethread (on Hemophilia) are posted on their blogs, so check them out!

Thanks for reading and wish us luck on our final!

Picture from:

Gruepig. Pickling Cucumbers. Digital image. Wikimedia Commons. MediaWiki, 12 Nov. 2005. Web. 12 Dec. 2014.

2 Week Biology Sum-Up!

Over the past two weeks, AP Biology has been action-packed. We have managed to squeeze in three chapters (give or take), an extra credit assignment. and an educational, outdoor fieldtrip!

The three chapters covered genetics, DNA replication, and protein synthesis. Genetics was more of a review of Mendel’s laws and punnett squares. I feel that genetics is the most interesting portion of biology because genetics and genes is what make our society diverse. DNA replication is interesting because in learning DNA replication my class and I could “connect the dots” about how DNA replication is the precursor for mitosis. In going in depth into DNA replication, I was able to grasp a better understanding of both concepts. Lastly, protein synthesis is where RNA is produced and used in order to code for specific proteins. This is important because through cell signaling, our bodies can produce the necessary proteins to keep the functionality of our bodies.

The extra credit assignment was to extract DNA from a strawberry using hose hold ingredients. I worked in a group of three with Bharathi Chinnakotla and Jennifer Parascandolo. The experiment is shown on all three of our blogs. Their links are: https://bharathisbioblog.wordpress.com/2014/11/26/strawberry-dna-extraction/ and https://biologybloggerr.wordpress.com/2014/12/01/strawberry-dna-extraction. This experiment really opened my eyes on how easy it is to extract DNA from a strawberry and that aspect really interested me. As Jennifer stated, "Me and my partners screamed of happiness because we thought we were not going to be able to do the project." The joy we felt lifting the DNA up was that of no other. We felt smart and capable of doing such an intricate experiment. Bharathi states that the experiment could have been improved if we "placed the DNA under a microscope."

The outdoor field trip encompassed within this two week period, was at the bay front park in Palo Alto. This field trip, although educational, was very fun as well. My class and I collected data on many aspects of the soil found at the bay front that could be used in order to better the environment there and improve the lives of the species.

Works cited

All pictures taken by Jennifer

Parascandolo and myself.

Saving the Bay

On Wednesday November 19, 2014, the AP Bio Rockstars made their first trip to the Palo Alto Baylands to work with Save the Bay. Students collected soil data and calculated biodiversity using Simpson's Biodiversity Index. The data collected will be shared with Save the Bay and added to the data collected by classes and groups around the bay. 

Here's more about the experience!

Created with Padlet

Meiosis in Motion Roundup

In my AP Biology class, we learned about cell signaling, mitosis, and meiosis in the previous unit. We had a project on each so that we could understand the material better. For cell signaling, we had a project where we made a digital presentation on the effects of Ebola on the signaling pathway. For mitosis, the class split in half, and one group made a three dimensional diagram of mitosis in a plant cell and the other made a three dimensional diagram in an animal cell. For meiosis, we individually made a moving presentation of the process in an animal cell. This project was by far the most challenging but the most beneficial.

We were allowed to work individually or with a partner, and the goal was to create a project to watch a cell divide. After completing the project, each student embedded the video into a blog post, including a summary of meiosis and their thoughts on the project.

Summary of Meiosis

In case you do not know what meiosis is, Bharathi Chinnakotla gives a precise summary in her blog post! She says,

"Meiosis is a type of cell division that is crucial for sexual reproduction because it creates variation and genetic diversity. In this type of cell division, one diploid cell undergoes two divisions to create four haploid cells. The two divisions that take place in meiosis are meiosis 1 and meiosis 2."

 This is Allie Coon's summarizes Meiosis I:

"In prophase I, homologous chromosomes (a pair of two sets of sister chromatids that carry different versions of the same genetic information) pair up and exchange genetic information by “crossing-over.” This is a very important step in meiosis, as this step allows for increased genetic diversity of the offspring. The rest of meiosis continues very much like mitosis does: the rest of prophase I sees the dissolution of the nuclear envelope and the formation of spindle fibers, while metaphase I includes pairs homologous chromosomes lining up along the metaphase plate. During anaphase I, these homologous chromosomes are pulled apart from one another, and two distinct cells are formed through telophase and cytokinesis."

Shauna O'Donoghue explains Meiosis II:

"In meiosis II, prophase II is the first step. In both cells the spindle forms and the chromosomes, made of two chromatids, move towards the center. In metaphase II the spindle fibers are lengthening and the chromosomes are in the middle at the metaphase plate. Next in anaphase II the spindle fibers begin to shorten and the chromatids move towards opposite poles in both cells. Lastly in telophase and cytokinesis II the two cells form haploid daughter cells leaving a total of four cells."

Amazing Project Videos

After summarizing Meiosis, each AP Bio Rockstar embedded her project into the post.

Here's Amanda Reshke and Simone Condé's project:

Here's Simran Lubana's video:

Comments and Thoughts

After posting the video, we made comments and shared our opinions on the project.

Rebecca Zheng commented: 

"For this project, the most challenging part was using Play Dough to create the phases of meiosis. The dough was often crmbly and difficult to mold, so some of the shapes we desired to create did not turn out as neat as we had hoped. However, because this project was incredibly hands-on, I think I was able to get a much better understanding of each phase of meiosis. Doing a project like this immerses me into a project far more than reading text from a book can. Overall, though this project was difficult, the challenge helped me understand and remember the process of meiosis much better."   

Elina Vanuska included a short reflection: 

"This project was very challenging because it required complete knowledge of what is occurring during meiosis and the skill and creativity to make a stop motion. The visual aspect of the project allows people to understand the topic easier, however this stop-motion was very difficult to create in the very short amount of time Nicole and I had to create it. However, with that being said, it was a good way to cover meiosis in a visual manner where we can actually see what is happening and I now have a better understanding of meiosis."

There are so many more amazing projects that I did not include in this blog post, so feel free to check out all the posts made by AP Bio Rockstars and see their masterpieces!

Mitosis and its phases!

This unit, in AP Biology, the class learned about cell communication and reproduction. The class worked hard and endlessly these past few weeks to understand the concepts of communication and reproduction.

One of the topics discussed in this unit was mitosis. The class learned about mitosis and the different phases of mitosis. The team also did a lab on mitosis and the duration of each of the phase. By using the class's knowledge about mitosis and its phases, the class had to come up with a way to figure out how long each phase of mitosis was by looking at onion root cells in a microscope. The AP Bio team had to put on their thinking caps to find solutions to problems.

The AP Bio team decided that the best way to figure out the duration of each phase of mitosis was by counting the total number of cells in view in the onion root slide and divide that number by the number of cells in each of the phases. Then, that number should be multiplied by 24 hours. That number would be the time each cells spends in each phase of mitosis. Another way people approached this problem was by finding the amount of time each phase takes in mitosis by using percentages (i.e. Entire Mitosis process would be 100%)

If you are following the AP Bio Blogs, you may have noticed that the class blogged about the mitosis phase lab. The class included a purpose, introduction, method and data.

Here’s how Shauna approached this lab:

1.  Take three samples of an onion root tip

2.  Take the first sample and focus it on the tip under the microscope

3.  Start by counting the total number of cells (an easy way to accomplish this is to count down and up and then multiply the two numbers to get an approximated value)

4.  Count the number of cells in each phase and record the number

5.  Divide the number of cells in each phase by the total number to get the percent of each one

6.  Next times the percent by 24 to find the total hours spent in each cell

7.  Repeat steps 2-6 with the other two samples
Check out Shauna’s Blog by clicking the link: http://journeythroughbiology.wordpress.com/

Here’s how Allie approached the lab:

1. Set up a slide of an onion root tip under a microscope with x.65 magnification.

2. Focus on a segment of the cell slightly above the tip of the root, and count the number of cells total in the segment.

3. Using the visual cues identified in the introduction, count the number of cells in each phase of the cell cycle (interphase, prophase, metaphase, anaphase, and telophase). Enter these numbers in the data table

4. Divide the number of cells in each stage by the total number of cells in the cell segment to determine the percent of cells that are in each phase of the cycle.

5. Repeat steps 1-4 two more times, using a different onion root tip cell slide each time.6. Calculate the average percent of time spent in each phase and multiply this number by 24 to get the hours spent in each phase of the cell cycle.

Check out Allie's Blog here:http://apbionce.wordpress.com/

The AP Bio team collected data that shows how long each phase of mitosis is:

Check out Rebecca’s data:

Data:

Anaphase: 0.309 hours (~18.54 min)
Interphase: 10.520 hours

Prophase: 5.768 hours

Metaphase 0.927 hours (~55.622 min)

Telophase: 3.091 hours
Time calculated with: 
(Total number of cells in a phase/ Total number of cells)  x 1440 minutes = total time of each phase                     
Data:

# of Cells	I	P	M	A	T	Total
Slide 1	61	33	5	3	27	135
Slide 2	68	23	4	2	3	99

	I	P	M	A	T	Total
Average # of cells	64.5	28	4.5	1.5	15	116.5

Check out Rebecca's Blog: http://biobloggingbecca.wordpress.com/

Check out Simone’s data:

Interphase		Prophase		Metaphase		Anaphase		Telophase		Total
	Trial 1	Trial 2	Trial 1	Trial 2	Trial 1	Trial 2	Trial 1	Trial 2	Trial 1	Trial 2	Trial 1	Trial 2
Number of cells	69	129	17	27	1	1	2	4	1	4	90	165
Percent of cells	77%	78%	19%	16%	1%	0.60%	2%	2.40%	1%	2.40%	100%

Check out Simone's Blog: http://simonesbioblahg.wordpress.com/

Overall, this lab was a lot of fun. At times it was difficult to identify the phases by looking at onion root cells in a microscope. However, by finding the phases in the cells, the class was able to understand what was happening in each of the phases. Also, figuring out how to find out the duration of each phase was challenging, but it made the class think and come up with creative solutions. This lab definitely helped the class better understand mitosis!