Friday, November 14, 2008
If you missed the segment when it aired, you can go to the link below to watch it:
I am very proud of my father...he is a real hero!
Euglena (only label the nucleus, chloroplast, flagellum and eyespot/photoreceptor)
They are too cute....and even cuter under the microscope!
Have a great weekend!
Wednesday, November 12, 2008
The Smallest Page on the Web
A-Z Microscope History
Any work not completed in class should be finished at home! :)
Sunday, November 2, 2008
Brandon, Period 6
Adam, Period 1
Timmy, Period 1
Kevin, Period 2
Kwame, Period 6
Sierra, Period 4
Alex, Period 2
Great job, everyone!!
Thursday, October 16, 2008
Book socks and the covers from the Media Center are not acceptable, as neither are designed for the larger sized textbooks that you have been given. So, instead, you should cover your textbook with either a paper grocery bag or a shopping bag from your favorite store! And, heck.....they're free!
If you do not know how to cover your textbook in this manner, I have photocopied directions to show you how (also found on the student links page at www.ShellysScienceSpot.com) and have linked the video below to help you out.
Have a wonderful weekend....and make those covers strong! Your textbook must remain covered all year long! (oooh, that rhymes) :)
Wednesday, October 8, 2008
Check out the video and tell me what you think. I'm getting lonely here without any comments from my students (the comment on the Simpsons video was from my friend!).
Enjoy your day off!
Saturday, October 4, 2008
In an effort to prevent both her and Isador from taking these unannounced vacations, I immediately turtle-proofed room 241A and purchased a baby gate from Target. Now Isador can join his big sister again in stretching their turtle legs in our classroom!
Tuesday, September 23, 2008
Here's a question for you.....and I want to see your responses (is anyone reading this out there?): which gas, when produced, enabled the "Homer-fish" to make their way out of the water and evolve into terrestrial (land-dwelling) animals?
Thursday, September 11, 2008
This week, we covered the Scientific Method....the systematic process in which we search for solutions to problems. Can you recall the steps of the Scientific Method in order?
- State the problem/Ask the question. What are you looking to solve?
- Gather information on the topic. Research the subject of your investigation (ask a professional, use the internet, go to the library)
- Form a hypothesis. Propose a solution to the problem.
- Experiment. Carry out a plan to test your hypothesis.
- Record and analyze data. Organize the information that you gathered in data tables or diagrams, and create graphs to visually represent your results.
- Form a conclusion. What can you conclude from your experiment? Was your hypothesis correct? What could you improve about the experiment?
In an experiment that you are looking to discover how effective something is, two test groups must be studied. One group will be the variable group, or the group that receives the factor that you are testing. The other group is the control, the group in which the variable is not altered. The control is used as a benchmark to measure the variable's effect.
Let's take a look at the following experiment that was designed to see how important rich soil is to the growth of a plant:
A student hypothesized that plants grown in poor soil will not develop as well as plants grown in good soil.
Both test groups must develop with the same conditions: same variety of plant seeds used, same amount of water used, both exposed to the same amount of sunlight, etc.
Only one factor can be different between the two groups; in this experiment, the type of soil used would differ. Only one variable can be tested at a time, or you will not be able to determine what caused the observed results. In this experiment, the variable was the type of soil used. The student was then able to conclude that plants grown in good soil grow taller than plants grown in poor soil. If the student had changed other conditions between the two groups, he may not be able to determine which factor actually produced taller plants.
We will end this week with a Scientific Method quiz and a review of appropriate laboratory behavior. Next week will begin with the characteristics of living things and the beginning of our unit on Evolution.
Enjoy your weekend.....create stunning lab safety posters over the weekend.....and rest up. Next week will be packed with learning!
Tuesday, September 2, 2008
This year will see some changes for us all - you will be adjusting to life in the Middle School, and we teachers will be getting used to the new bell schedule (the students are not the only ones who will be checking their schedules to see where they have to go!). However, just like with everything else, we will get used to these changes and wonder why we ever thought that they would be challenging!
Hopefully, your new locker will not be giving you any trouble....but just in case it is, either ask a nearby teacher for help or watch the video posted below to help you navigate through the unlocking process:
I hope that your first day in the Middle School went very well. I am very excited to start this new school year with you! Please remember that your teachers are always there for you if you have any questions or need to talk about anything.
Have a wonderful and successful 2008-09 academic year!
Tuesday, July 29, 2008
Drum roll, please........
www.ShellysScienceSpot.com is ready for business (well, with just a few more pages to complete)!
Take a look at it and tell me what you think...do you like it? Should I add something to it?
I'm wondering if anyone is checking in over the summer to check this blog, and hoping that if you are, that your summer is going really well! Before we realize it, Labor Day will be here, to be followed by the first day of school! Enjoy the gorgeous weather while it lasts!
Thursday, July 24, 2008
Friday, May 16, 2008
This weekend, all of my little Geneticists will be busy completing the Bikini Bottom Genetics Take Home Test. Since the test is to be completed at home, I do expect for you to use your resources - your notebook, this blog, the internet, your textbook....whatever you need to do your best on the test. In this post, I will include reminders to several key concepts about Genetics, probability and Punnett Squares. Make sure that you read each question on the test carefully, check your work and do the best that you can!
Vocab to help you with the test (also found on your yellow vocabulary sheet):
- Allele - an alternate form of a gene. For our study of Genetics in 7th grade, we are only working with genes that have two alleles for each trait (humans are much more complex than this, though). Represented using letters (ex: H, h, B, b, T, t)
- Homozygous - genotype in which the two alleles in the pair are identical (ex: HH, hh). Also known as a purebred.
- Heterozygous - genotype in which the two alleles in the pair are different from one another (ex: Hh). Also known as a hybrid.
- Phenotype - the physical characteristic displayed by the trait (ex: brown hair, blue eyes). Can be observed.
- Genotype - the actual genetic makeup of the organism (allele pairs). Not always able to be observed. (ex: BB, Bb, bb)
- Dominant - form of the trait that is always expressed. Represented using uppercase letter (ex: H, B, T)
- Recessive - form of the trait that is only expressed when paired with another recessive allele. Can be masked by a dominant allele; represented using lowercase letters (ex: h, b, t)
That's a good review to enable you to work your way through the test if you lost your vocabulary sheet (which, I hope that you didn't!).
Everyone has done such a great job working with the Punnett Squares this week - every Junior Geneticist in Team 7A has been correctly identifying the genotypes of two parents, properly placing them on the outside of the Punnett Square and accurately crossing the parents to find the possible genotypes of their offspring. However, word problems (like the ones on your take home test) are a bit trickier....here are a few steps to get you through them:
2. Identify the genotypes of the parents
3. Write the genotypes of the parents along the top and side of the Punnett Square (one allele along each box)
4. Perform the cross, including two alleles in each box
5. Determine the phenotypes of the offspring's possible outcomes (refer to the question to determine which form of the trait is dominant, and which is recessive)
6. Answer the question
Don't forget that I will be collecting the tests during homeroom on Monday (I will notify your homeroom teacher to collect them and give them to one of my homeroom students as the come around) so that 4th period does not have more time to work on it than 1st period does. I will not be accepting any tests in class Monday or on Tuesday. If the school attendance documents your late arrival, I will be accomodating, however, for all other circumstances, THERE WILL BE NO LATE WORK. Absences on Monday will be handled individually.
Get the test over and done with early, so that if you have any questions you can email me immediately and so that you can enjoy the remainder of your weekend without the test hanging over your head!
Have a great weekend!!! No more rain!! : P
Tuesday, May 6, 2008
Meiosis II (second cell division)
Not only does cell division replace cells that needed for growth and repair, but a special type of cell division is necessary to produce gametes, or reproductive cells. In males, we call these gametes sperm cells, while they are referred to as egg cells in females. Meiosis is the special type of cell division that only produces reproductive cells.
Why do we need a different type of cell division for reproductive cells? Well, consider this: Mitosis produces daughter cells that are identical to the original parent cell, right? If our reproductive cells were produced through mitosis, we would have the same number of chromosomes in our sperm and egg cells as we would every other cell in our body, which, for humans, is 46. If a man and woman, each containing 46 chromosomes in their sperm and egg cells, conceive a child, his sperm cell would combine with her egg cell. So, his 46 + her 46 would = 92 chromosomes in their child! Not good, since each species is supposed to maintain the same number of chromosomes (humans 46, fruit flies 8, etc). Can you imagine if the 96 chromosome child grew up and reproduced on her own, conceiving a child with a 96 chromosome man?? Their child would have 192 chromosomes! It would never end!!!!
So, how do we maintain a consistent number of chromosomes in our species? The answer is simple: meiosis produces reproductive cells that contain half the number of chromosomes as our regular body cells. This means that human sperm and egg cells each have 23 chromosomes. Let's revisit our example from the previous paragraph.....If a man and woman, each containing 23 chromosomes in their sperm and egg cells, conceive a child, his sperm cell would combine with her egg cell. So, his 23 + her 23 would = 46 chromosomes in their child. Good? You bet!
How is meiotic cell division different than mitotic cell division?
1. Meiosis only produces cells that are to become gametes. All other cells divide by mitosis.
2. In meiosis, the cells divide twice. However, the chromosomes are only copied before the first division. Mitosis includes only one cell division, which always includes chromosome copying.
3. Daughter cells produced by meiosis are haploid (n), meaning that they contain half the number of chromosomes as the parent cell. In humans, this is 23. Mitosis produces diploid (2n) daughter cells, meaning that the cells are identical to the parent. These cells have a double set of chromosomes. In humans, this is 46.
4. Meiosis produces four daughter cells at its completion. Mitosis only produces two.
During Wednesday's class, we will be visiting The Biology Project's Meiosis Tutorial and completing work to learn more about meiotic cell division. Thursday's quiz will focus on identification of the phases of mitosis, as well as the major differences between mitosis and meiosis (as listed above).
Once we finish cell division, we will get into Mendelian genetics and really begin to practice the meat and potatoes of Genetics! I'm excited for some punnett squares....are you?
Monday, May 5, 2008
Today in class, we talked about the cell cycle, and, more specifically, cell division. The cell cycle itself is the entire process through which the cell prepares for division and then actually divides. The entire process of preparation and division takes a long time in adults - anywhere from 18 to 24 hours!
The cell does a lot in preparation for division - it has to duplicate its genetic material (DNA) in order to ensure that its daughter cells are identical to the original cell, and grow to accomodate its expanding contents. This part of the cell cycle, known as interphase, is so important that it occupies the vast majority of the cell cycle. Out of roughly 22 hours, 21 are dedicated to preparing for cell division!
The remaining hour-ish is occupied by cell division, known to us science folk as mitosis. There are four major phases of mitosis through which a cell divides:
Once the cell completes telophase, it is ready to split in two. This is the final stage of the cell cycle, also known as cytokinesis.
This type of cell division occurs in your non-reproductive body cells in order to allow you to grow (the bigger you get, the more cells you contain), develop and repair injuries that you sustain. Cell division is very important!
In an adult, it may seem as though cell division occurs rather slowly....compared to an embryo, it is slow! Remember, adult cells proceed through the cell cycle within 18-24 hours. Embryonic cells, however, divide every 30 minutes! That means that within a half an hour of your conception, you became two whole cells. An hour after you were conceived, you were nothing but 4 cells; after 90 minutes you were 8 cells; within 2 hours you were 16; then 32, then 64; then 128, and so on and so on, until you were born as a multicellular baby with specialized cells! All of that has to happen very quickly!
To revisit the interactive mitosis tutorial, visit the following website:
This week, we will also learn about how a different type of cell division, called meiosis, produces reproductive cells (sperm and egg cells) and how it compares to mitotic cell division.
This week's key terms:
- cell cycle
- asexual reproduction
- binary fission
Have a great week! Sorry, but I have to split! : P
Monday, April 28, 2008
We will start off the unit by learning about cell division. Sound familiar?? If you recall, we first learned about cell division way back in the Bacteria and Viruses Unit when we discussed how bacteria reproduce through a process called binary fission. Cell division occurs in all living things, from uni to multicellular. Cell division enables unicellular organisms (like bacteria and protists) to reproduce, while helping multicellular organisms (like humans) to grow, develop and repair themselves.
Before a cell divides, it must first make sure that each daughter cell will be identical to itself - it does this by making a duplicate copy of its genetic material, DNA. DNA (short for deoxyribonucleic acid) is a chemical that contains all the information needed for an organism's growth and functioning. It is comprised of two strands of molecules that twist around one another, like a twisted ladder. The two strands are connected in the center by chemical rungs. We call this structure a double helix.
DNA is located within the nuclei of eukaryotic cells. Most of the time, DNA looks like loose strands. However, before the cell divides, DNA wraps itself around proteins and forms structures called chromosomes. The chromosome is made of two identical structures called chromatids that are held together in the middle by a centromere. Humans have 46 chromosomes in each of their non-reproductive cells - a number that is consistent throughout the human species. Other species have different chromosomal numbers - fruit flies have 8 chromosomes, dogs have 78 and cats have 38.
Additionally, the DNA is very well wrapped around the chromosome's protein core - if you stretch out a single strand of DNA, it measures approximately 2 meters! Even cooler - some sources state that if you line up all of the DNA in all of the cells in your body end-to-end, it can reach from Earth to the Sun and back - 70 times!
All of this is very important for the development of any organism - unicellular organisms reproduce by cell division and therefore need to ensure that their offspring have the same genetic information as themselves. Cell division is very important to you, as a multicellular organism, as well. Each one of us started out as a single fertilized egg cell. Through cell division after cell division, we became multicellular. Cell division enables you to grow - the bigger you get, the more cells you have, to the point where an adult human can have about 100 trillion cells! From one to 100 trillion....amazing!
This week, we will also be sitting for state testing in Language Arts and Math. There is no science component for the 7th grade (though there is one in 8th grade). Testing will take place in the morning, and the afternoons will have an altered schedule so that every class meets at least twice during the week. The schedule is as follows:
- Tuesday: testing until 11:28, periods 3, 4, 5, 6
- Wednesday: testing until 11:48, periods 3, 4, 2, 1
- Thursday: testing until 10:48, periods 3, 4, 5, 6
- Friday: testing until 10:48, periods 3, 4, 2, 1
During the test week, don't forget to stick to these basic guidelines:
- Get plenty of rest the night before (be in bed way before 10pm!).
- Eat a nourishing breakfast the morning of the test.
- Arrive to school on time!
- Read the directions carefully, paying close attention to what the question is asking you to do.
- Stay relaxed and do the best that you can.
Friday, April 18, 2008
Yes, we made it! Hackensack Middle School is officially on Spring Break for one whole week!
I hope that everyone takes the time off to relax, play, sleep late and mentally prepare for the week of NJ ASK testing coming up.
I hope that some of you will be visiting locations outside of Bergen County - if you do, make sure to send me a postcard and make me totally jealous! The furthest I'll be traveling is to Paramus, though I wish that I were laying in that hammock on a powdery soft beach somewhere in the Caribbean. Maybe on the next vacation.......
Have a great Spring Break! When we return, we'll begin our Genetics unit!
See you in 10 days!
Sunday, April 13, 2008
I apologize to all of my students for neglecting to update this blog!!! : (
As you all know, I have been ridiculously busy working on projects for Graduate School (which I am looking forward to using with you kids - you can check out my Charles Darwin project and my U.S. Oil Spills project online.....let me know what you think!) as well as putting together the website for your Unit Project, which is due very soon. You can access the Human Disease Project website here, as well as on homeworknow.com.
Along with the excitement of looking forward to spring break, this week will be a busy one for the 7th grade Life Science students! This week, we will be:
- Reviewing for the Human Body Systems Unit Test
- Taking the Human Body Systems Unit Test
- Preparing our notebooks for collection on Tuesday
- Presenting completed Human Disease Project work
I am truly looking forward to seeing each student's presentation on the disease that he/she chose! Just remember, PowerPoint presentations will be presented off my laptop, so the best way to avoid any last-minute problems is to email me the presentations ahead of time (firstname.lastname@example.org) . One hard copy (paper) of the presentation must be submitted, as well.
Because of the response that they received in class, I included the link to the Optical Illusions used in the Nervous System lesson on Wednesday in the "Favorite Links" section to the right. You can also access it directly by going to http://saintderanged.co.uk/OpticalIllusions.html. My favorite is #8, showing where your blind spot is!
Good luck with your project's finishing touches, review for Tuesday's test on the 10 body systems that we studied, and have a great weekend!
Spring Break, here we come..
Saturday, April 12, 2008
Friday, January 11, 2008
Visit the following websites and complete the Mollusk/Echinoderm chart:
Make sure to finish "It's Hard to Ignore a Squid" based on the information that you read on the websites!
And, most importantly.....dont' forget to do the official "Ms. Tiboldo Snow Preparations" in anticipation of a snow day on Monday! To ensure a snow day, you must:
- Place spoons under your mattress
- Wear your jammies inside out and backwards
- Do the "Snow Dance"
- (Most important) DO YOUR HOMEWORK!!
(wink, wink) See you Tuesday!!