Yeast Monohybrid Cross

During the last two weeks, the upper graders worked on their monohybrid yeast cross project. They started by preparing petri dishes with agar, then they cultured the yeast strains, and performed a cross between two heterozygotous (Rr x Rr - R being the dominant allele coding for white yeast, and r the recessive allele coding for red yeast).
Each student has a handout describing the experiment, and they had to answer some genetics questions throughout the project. If you want to see your kid's work, take a look at his/hers science folder. I also gave them a quiz about the basics of genetics on Wednesday so that I can see if there are any misunderstandings that I should address in the next two weeks (my last weeks with them). I am honestly amazed with how smart these kids are! They learn extremely fast, and ask very smart questions. It is a pleasure to work with this group!
Students will be writing a lab report - with introduction, methods, results and discussion sections - next week. We have talked about the structure and purpose of scientific papers, and I will be helping them with their reports next Monday. Below are some pictures of the kids working on this project.

McLaughlin Field trip

As you all know, on November 2nd we went to the McLaughlin reserve to plant the native grass seedlings. Below are some pictures from our field trip.

End of cell biology unit - beginning of Evolution and Genetics

Last week, on Monday, students presented their cell models (photos posted below). They were all very good! I noticed a few misconceptions during the presentations, so we spent a few minutes reviewing some organelles.

Since we had the field trip to McLaughlin the Friday before, I asked students to write two paragraphs about the field trip. The Knoxville area, where we planted the seedlings, has an interested history so I asked the kids to use this restoration project to illustrate John Muir’s quote: “When we try to pick out anything by itself, we find it hitched to everything else in the Universe.”

On Wednesday, I had three “stations” for them. One was focused on microscopy, and the other two were worksheets – origin of life on Earth and development. I was at the microscope station talking to them about the parts of a microscope, showing them how to prepare a wet mount, and helping them prepare a slide with a piece of elodea, and a slide with their cheek cells (picture below). While one student was with me, the others were working on their two worksheets in their classroom, with Chris. This was the last “official” class covering cells. My goal was to have them think about how the first cell evolved, and to get an initial appreciation of development. This was the last “official” class because on Wednesday we will discuss the worksheets (recall that they are due on Wednesday!).

We have covered all concepts of the 7^th grade standards concerning cells:

Cell Biology

1.      All living organisms are composed of cells, from just one to many trillions, whose details usually are visible only through a microscope. As a basis for understanding this concept:

a.       Students know cells function similarly in all living organisms. b. Students know the characteristics that distinguish plant cells from animal cells, including chloroplasts and cell walls.

c.       Students know the nucleus is the repository for genetic information in plant and animal cells.

d.      Students know that mitochondria liberate energy for the work that cells do and that chloroplasts capture sunlight energy for photosynthesis.

e.       Students know cells divide to increase their numbers through a process of mitosis, which results in two daughter cells with identical sets of chromosomes.

f.          Students know that as multicellular organisms develop, their cells differentiate.

Today we started the evolution/genetics unit. I started by having them tell me what they knew about evolution. They mentioned adaptation, human evolution, and inheritance. We had a good discussion about how these terms are related to evolution, and then I provided a definition, and an example of evolution by natural selection. The example was about the peppered moth during the industrial revolution. We had talked about this example before, and I was surprised to hear how many details they remembered! I then talked to them about Darwin - his voyage, and observations about the finches. I briefly mentioned that Darwin wasn’t the only person working on the idea of evolution by natural selection  (talked about Wallace), and we played a natural selection game at the end of class. The purpose of the game was to illustrate evolution by natural selection at two different levels – predator and prey. Each student had a tool (2 had spoons, 2 had forks, and 2 had plastic tweezers); we walked to a patch of grass by the parking lot where I had previously thrown 100 colored toothpicks (25 of each color - green, yellow, blue and orange), and they had 5 minutes to find, and get toothpicks using their tools. Before leaving the classroom, I asked them to predict the results.  As predicted, colors that could camouflage with the background (yellow toothpicks were blending in with fallen leaves, and green toothpicks are hard to see in the grass) were the most successful at surviving since only 8/50 were found. Orange and blue toothpicks were more easy to spot – 28/50 were found.We spent the last few minutes of class discussing how this game is relevant to evolution by natural selection. 

This is an aggregation of cheek cells. You can see the nucleus in most of the cells.

Cell Biology continuation

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During the first part of science class today, we talked about plant cells. I asked students to think about what structures studied so far (in animal plants) might be found in plant cells. They mentioned cell membrane, nucleus, nucleolus, rough endoplasmic reticulum, and smooth endoplasmic reticulum. I talked about the cell wall, vacuole, chloroplast, mitochondria, and plasmodesmata. We made a drawing of a plant cell with labels and descriptions. I then assigned their cell model homework (due next Monday, November 5^th). We have 3 students working on animal cell models, and 3 working on plant cell models. They will present their models on Monday. I gave them printed instructions for this project (will send parents an electronic version), and they are encouraged to use their drawings from class, and reliable Internet sources (feel free to ask me for references if you don’t know much about the subject) when working on this.

After the break, we talked about DNA – chromosomes, and structure of DNA. My goal was to provide basic, introductory information about transcription and translation so that we could play the “genetic Frankenstein game”. This game can be used for an active, interactive introduction to genes, transcription and translation. Kids are assigned a few physical traits, and asked to build a piece of DNA coding for the assigned traits (codes were provided to students on a handout that is in their science binder that should go home this week). At the end of the game, kids translate the sequences into a Frankenstein drawing. Unfortunately, we were running out of time, and I feel like most concepts weren’t clear. I will spend more time on this activity next week.

A quick note: we will eventually talk about evolution of life on Earth and have a discussion about cells from an evolutionary perspective.

Katrin had enough time to finish a piece of the DNA molecule for the genetic Frankenstein game.

Cell Biology

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This week my focus was on cells. We started by discussing functions of cells, and then started summarizing the structure of an animal cell. I was drawing on the board and having kids draw with me on a paper that will be kept in they science folder (I am not sure if all parents know, but each student has a science folder with all the work that they have been doing). We started with the cell membrane (lipid bilayer with proteins embedded), its functions (protection and regulation) and structure. We also talked about the nucleus; we talked about DNA and RNA (briefly, will talk more about their functions in the near future), the endoplasmic reticulum (rough and smooth), mitochondria, golgi apparatus, lysosome, vesicles, centrioles, and cytoskeleton.

The kids were really interested in the names and functions of the organelles. On Monday, Luke asked about the size of cells (why they can’t be huge), so on Wednesday we talked about diffusion (passive transport of molecules across membrane). We played a game outside – two kids were oxygen molecules, three were the plasma membrane, and two were mitochondria – we then had a discussion about the amount of energy required for diffusion in small vs. large cells. We ended the class with a you tube video (tour of the cell) and I gave the kids the link to a website that summarizes the structures and functions of cells. Next week I will assign a homework project; I will have each student build a model of a cell (plant or animal). They will have one week to work on this, and the link I provided could be helpful for this assignment. I will provide more information about this project next week.

At the very end of class, we talked about the restoration project. We are going to McLaughlin next Friday. Anybody is welcome to join us. We have about 60 seedlings to transplant.

The following standards were covered this week:

7^th grade Life Sciences

Cell Biology

1.      All living organisms are composed of cells, from just one to many trillions, whose details usually are visible only through a microscope. As a basis for understanding this concept:

a.       Students know cells function similarly in all living organisms. b.  Students know the characteristics that distinguish plant cells from animal cells,

including chloroplasts and cell walls.

c.       Students know the nucleus is the repository for genetic information.

d.      Students know that mitochondria liberate energy for the work that cells do.

Next week we will talk about plant cells, and if we have time I will start talking about cell division and differentiation. I will have a summary of the restoration project for kids to read in the car (it will take us a little over 2 hours to get to McLaughlin). 

Below are two pictures of the kids playing the diffusion game:

Becca, Julia, and Katrin were representing the cell membrane.

Garnet was an oxygem molecule looking for mitochondira.

New biology unit

            Last week we only had science class on Wednesday (I wasn't feeling good on Monday). We spent our time finishing the geology unit and checking on our seedlings for the restoration project. The kids had to finish a geology worksheet, finish their geological timeline, and start extra seeds on germination towels. We are going to McLaughlin on Friday, November 2nd, to plant seedlings at the restoration site.
          On Monday we started an unit about life, and cells. This unit will lead us to genetics. I started the class by asking students to discuss, in groups, what it means to be alive. I asked them to create a list of characteristics that can be used to classify things as living or nonliving. Both groups had common characteristics in their lists, including: movement, cells, evolution and energy. I showed them a few pictures and asked them whether they were looking at living or nonliving things. The class wasn't sure about the classification of seeds, fire and coral reef. We then discussed a few more characteristics of living things (respond to stimuli and have metabolism).
          After this discussion, we had our first "lab". I had a small microscope connected to my computer, and we used it to examine our skins, our clothes, sand, leaves, an ant, Vaca's hair and nose etc. We had fun! Chris took some pictures that I will be adding to this post (bottom).
          Today, Wednesday, we concluded our discussion about characteristics of living things and had a brief discussion about genes and evolution. It was a very interesting discussion - the kids were really involved and actively discussing their thoughts. One of the students asked me why some plants have thorns and I asked them why thorns would be an advantage for the plant. Katrin and Rodrigo talked about protection (of genes), and Garnet was really interested in knowing why/how new traits establish. I told them that mutations are random events, Luke pointed out survival of the fittest and we talked about adaptation.
          On Monday, a few students weren't convinced that seeds are living things so we dissected a bean today. I showed them the embryonic leaves and root. During the last few minutes of class, students looked, under a microscope, at single celled organisms that live in Putah creek.We saw algae and rotifers. Next week we will take a look at cheek cells, plant cells, and some more protists.

Yosemite's Biotic Zones project

 In the last two weeks, students have been learning about the 5 biotic zones found in Yosemite. They spent the first day summarizing their assigned zones and had two sessions to work on the models.

Becca and Garnet worked on the foothill-woodland zone and the lower montane forest. Josh, Luke, and Rodrigo worked on the upper montane forest and on the subalpine forest. Julia and Katrin were responsible for the alpine zone and fire ecology.

Yesterday, Wednesday Oct. 3, students presented their projects to the lower grades.

Here are some pictures of the final projects: 

Geology Friday - Pictures

Here are some pictures of last week's geology Friday session:

Julia, 7th grader, demonstrates how a glacier moves while 3rd-4th graders observe.

3rd-4th graders take a closer look at how glaciers shape landscapes.

5-7th graders present the plate tectonics poster.

Rodrigo presents the plate tectonics poster to 3rd-4th graders.

Teacher Pa helps 3rd-4th graders with the rock cycle activity.

Making mold fossils.

Week 3 - end of the geology unit

This was a science intense week! The upper grades had geology class on Monday, Tuesday and Wednesday, and on Friday they helped teacher David and I teach the material that they have learned in the past two weeks to the lower grades.

On Monday we reviewed the plate tectonics worksheet, and talked about the rock cycle. We did an activity using crayons to illustrate the rock cycle. Students were separated in three groups, each group had 3 crayons of one specific color. The crayons represent different types of rock. Students were told to shave the crayons, and I asked them what part of the rock cycle this action was representing. It was clear that all students knew that the shaving was representing erosion. The next step was to place the crayons' shavings on a piece of aluminum foil - one color at a time, and one layer on top of the other. This resulted in the formation of a sedimentary rock. After all students had a chance to take a look at our model of sedimentary rocks, I closed the aluminum foil, and asked each student to apply pressure to the package. Metamorphic rocks are created when other types of rocks are exposed to heat and pressure. After examining our crayon metamorphic rock, we went to the kitchen and placed our foil in boiling water for about 10 minutes. The melted crayons were allowed to dry until the next day. The boiling part of this project simulates the formation of igneous rocks.

On Tuesday we took a look at the cooled igneous rock, and then we tried a slightly different approach to make fossils (mold and cast) with clay and plaster. I brought small paper cups to the classroom, and asked the kids to make smooth balls of clay to place inside the cups. They placed the clay inside the cup, flattened the top, and applied a small amount of Vaseline on the surface. Each student chose a small plastic animal, and pushed it on the surface of the clay to make a mold. When they were done with their molds, I poured platser in the cup until it was almost filled and the plaster was left to dry. After this project, students were divided into two groups (one group was responsible for preparing posters and presentations for the first and second graders, and the other group was responsible for preparing posters and presentations for the third and fourth graders).

On Wednesday we checked on the fossils and were happy to find out that we were successful with our second approach.  I presented a mini lecture on glaciers that covered the following topics:
- What are glaciers? How are they formed and how do they move?
- How can glaciers shape landscapes? My focus was on plucking, abrasion, and moraine formation.
Students seemed to be very interested in this subject! Most of them didn't know much about glaciers, and they showed a lot of interest in the topic. After my presentation, the two groups prepared a glacier to be used in Friday's geology session, and they had approximately 45 minutes to work on their posters and practice the presentations.

On Friday we had a geology session for the whole school in the morning. There were four half-hour activities. Teacher David helped the older kids work with the first and second graders, and I helped those that were working with the third and fourth graders. You can find a summary of what we did on David's blog (http://grainworldsand.blogspot.com/). I was really happy to see, and hear from David, how the upper graders were knowledgeable about the geological concepts being covered. The students who were working with me in Brittany's class did an EXCELLENT job answering questions and presenting their posters. Unfortunately, we didn't have much time to talk to the 5-7th graders about how to present the information and introduce the activities, so David and I ended up doing most of the talking.

Science Content Standards for California public schools - week 2

Here is a list of the standards that have been introduced during last week's (week 2) activities:

Grade 6 - Focus on Earth Sciences

1.    Plate tectonics accounts for important features of Earth’’s surface and major geologic events. As a basis for understanding this concept:

a.    Students know evidence of plate tectonics is derived from the fit of the continents; the location of earthquakes, volcanoes, and midocean ridges; and the distribution of fossils, rock types, and ancient climatic zones.

b.    Students know Earth is composed of several layers: a cold, brittle lithosphere; a hot, convecting mantle; and a dense, metallic core.

d.    Students know that earthquakes are sudden motions along breaks in the crust called faults and that volcanoes and fissures are locations where magma reaches the surface.

e.    Students know major geologic events, such as earthquakes, volcanic eruptions, and mountain building, result from plate motions.

f.    Students know how to explain major features of California geology (including mountains, faults, volcanoes) in terms of plate tectonics.

Grade 7 - Earth and Life History

4.    Evidence from rocks allows us to understand the evolution of life on Earth. As a basis for understanding this concept:

c.    Students know that the rock cycle includes the formation of new sediment and rocks and that rocks are often found in layers, with the oldest generally on the bottom.

d.    Students know that evidence from geologic layers and radioactive dating indicates Earth is approximately 4.6 billion years old and that life on this planet has existed for more than 3 billion years.

e.    Students know fossils provide evidence of how life and environmental conditions have changed.

Week 2 - geological time line and fossils

      On Monday we talked about the geological time scale and discussed how geologists can learn from fossils. Students were divided in 3 groups, and each group was responsible for learning about certain eras in order to prepare a geological time line poster for their classroom. Students used the following website for their research: http://www.ucmp.berkeley.edu/help/timeform.php . In addition to the time line project, we tried to make fossils (molds and casts) using clay, plastic animals and plaster of paris. Unfortunately the fossil project didn’t turn out as planned, but we will try again!

    On Wednesday, students had approximately 35 minutes to work on their time line poster. During the remaining 40 minutes students worked on a worksheet designed to introduce them to plate tectonics. If you want a copy of the worksheet, please don’t hesitate to contact me. The worksheet was based on the following website: http://www.learner.org/interactives/dynamicearth/index.html . On Monday we will have a discussion about plate tectonics with a focus on the geology of CA. My goal is to have students appreciate geological processes before experiencing Yosemite.

    I was really excited to see our grass seedlings today! Becca and Katrin did a great job watering the soil.  

Summary of our first science class

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Today in science class, 5^th – 7^th graders summarized the scientific method and made connections between the steps of the scientific method and the skills/type of thinking that they will be using to organize their portfolios. After our discussion about “what scientists do”, we spent some time summarizing a few terms that we will be using over the next 3 months.

1)   Hypothesis: A supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation. An educated guess.

2)   Species: A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.

3)   Native species: a species is defined as native to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention

4)   Alien species: An introduced, neozoon, alien, exoti, non-indigenous, or non-native species, or simply an introduction, is a species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental.

5)   Invasive species: Non-native species that threaten ecosystems, habitats or species.

6)   Restoration: The action of returning something to a former owner, place, or condition

 After defining these terms, my focus was on introducing the concept of intraspecific variation and differential survival. I used dog breeds as an example of within species variation, and the peppered moth story (during the industrial revolution) to illustrate differential survival. I think that students understood the concept! If you talk to them about this at home and notice any misconceptions please let me know!

 During the last 30 minutes, 3^th  -4^th graders joined us to help 5^th -7^th graders plant seeds of 5 CA native bunchgrass species.  Students will monitor seedlings for the next 2 months. On November 2nd, we are going to McLaughlin natural reserve where we will all have the opportunity to plant native grasses at a restoration area. : )   

Unfortunately, I can’t stay at the school past 3 PM to meet you all, but please feel free to contact me at fonseca.carolina9@gmail.com if you have any comment, question or concern.   

First class

Hello!

Next Wednesday, September 5^th, Chris’s students will have their first science class with me. I have two primary goals for the first day:

(1) Review a few concepts, including the scientific method and differences between native, alien, and invasive species.

-->  These concepts will be discussed during a power point presentation summarizing my research. I am currently studying divergent evolution in early traits of development in 3 California native grass species. My research was designed to help an ongoing restoration effort in one of UC Davis’s natural reserves (http://nrs.ucdavis.edu/McL/index.html).

              

                When choosing seeds for a restoration project, scientists and land managers need to ensure that the biological material being used presents: a) local adaptation to the restoration site (for successful establishment of populations), and b) genetic diversity within populations to increase the likelihood that populations will survive under various environmental conditions.

My hope is that by the end of the presentation students will know, and have a clear example of, how scientists (ecologists in particular) approach questions/problems. 

(2) Plant seeds that will be used in the restoration project mentioned above.

        -->   Students will spend the rest of our time together planting seeds of 5 CA native grasses: Festuca idahoensis, Bromus carinatus, Hordeum brachyantherum, Nasella pulchra, and Elymus glaucus. We will plant approximately 300 seeds but only a fraction of those will germinate and survive until November 2^nd, the day in which we will plant the grasses at the McLaughlin reserve. I will post more information about this project before the field trip to the reserve.

Welcome!

             “A human being is a part of the whole called by us universe, a part limited in time and space.  He experiences himself, his thoughts and feeling as something separated from the rest, a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty.”  -- Albert Einstein 

   Welcome to my blog! The purpose of this blog is to inform parents about what I will be doing with the kids in science classes at Peregrine School. To initiate this blog, I would like to introduce myself, and give you a broad summary of what I will be doing at the school in my first year.

     My name is Carol Fonseca, I have a B.S from UC Davis in plant biology, and am currently working towards my M.S in Evolution, Ecology and Conservation biology at Sac. State. I have been teaching (and loving) lower division biology labs for one and a half years and am pleased to have this opportunity to work with kids! My research focus is on applied evolutionary biology. 

     During this school year, I will be working with 5 - 7th graders from September through December, 3rd - 4th graders from January through March, and with 1st - 2nd graders from April through June. I am really excited about the Yosemite field trip, and will spend the first month helping 5 - 7th graders learn about the geology and ecology of Yosemite. After the Yosemite field trip, my focus will be on cell biology, structure and function of organisms.

     In the beginning of 2013, the main project will revolve around vernal pools and I will be working with 3rd to 4th graders. I will finalize the school year working with 1st - 2nd graders on general biology, topics will include plant and animal biodiversity. I will be using the national standards for science throughout the school year.

      Looking forward to meeting everyone soon.