Entries Categorized as 'Biology'

How the Immune System Works

October 9, 2014

Awesome video by Kurzgesagt explaining “Why You Are Still Alive“.

Citing this post: Urbano, L., 2014. How the Immune System Works, Retrieved April 27th, 2017, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Sumac Berry Juice

July 25, 2014

Sumac berries.

A bunch of sumac berries on the branch.

Ripe, bright-purple sumac berries are quite astringent. Steep a ripe bunch in a quart or two of hot water for a few hours (or cold water for a day) and the result is a tart tea. Add a third of a cup of sugar to make a delicious juice. (Note: Poison sumac is not found in Missouri, but it has been identified in adjacent, eastern states, so be careful.)

Citing this post: Urbano, L., 2014. Sumac Berry Juice, Retrieved April 27th, 2017, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Dandelion Season

May 8, 2014

Preparing the flowers for frying.

Preparing the flowers for frying.

The last two weeks have been peak dandelion season here in eastern Missouri, so I’ve been experimenting with the culinary uses of the flowers.

Dipped in batter and fried, the flower heads did not taste like much. Probably too much seasoning and too much batter. It was good advice to cut off as much of the green outer covering (the sepals) because they are bitter. However, if you cut too close to the base of the petals they fall out all over the place, which is good if you want to collect just the petals.

Dandelion flower fritter.

Dandelion flower fritter.

Collecting the petals only is great if you’re trying to make dandelion wine (I’m adapting the second recipe from here), except that I’m only using petals (2 quarts). I keep the same amount of sugar (3 lbs), oranges (4), water (1 gallon), and yeast (winemaker’s). This is the appropriate timing for this project since we just covered the differences between aerobic respiration and fermentation.

Two quarts (about 4 liters) of dandelion flowers for making a gallon of wine.

Two quarts (about 4 liters) of dandelion flowers for making a gallon of wine.

Citing this post: Urbano, L., 2014. Dandelion Season, Retrieved April 27th, 2017, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

The Eggs have Arrived

April 14, 2014

After waiting an eternity (about two weeks) the Middle School business’ eggs have arrived.

Eight eggs in their packing.

Eight eggs in their packing.

We set up the incubator downstairs in the pre-school/Kindergarden classroom so Mrs. D’s kids will have the chance of monitoring them. The little kids will be responsible for turning the eggs, while the middle schoolers have set up a data logger and a couple temperature probes to keep track of the temperature in the incubator.

The incubator was provided by Ms. Mertz. It’s put together out of plywood with a 75 W incandescent light bulb as the heat source. Unfortunately there is a significant thermal gradient and although we salvaged a couple of computer fans for the purpose we did not get around to installing them –and more importantly testing them– in the incubator before the eggs arrived.

We’ll see how it goes.

Citing this post: Urbano, L., 2014. The Eggs have Arrived, Retrieved April 27th, 2017, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Radiolab: The Extinction of the Dinosaurs

March 31, 2014

RadioLab has an excellent podcast featuring Jay Melosh, a geophysicist who specializes in impact craters, and who advocates the hypothesis that the entire extinction event that killed off the dinosaurs at the boundary between the Cretaceous and Tertiary (the K-T boundary) took place over a period of two hours. The asteroid impact vaporized the crust of the Earth where it hit (near the Yucatan peninsula) and blasted this rock gas into space. There it cooled down to create little glass particles that reentered the atmosphere. On reentry the glass burned up, but there was so much of it that it raised the temperature of the atmosphere by several hundred degrees Celsius. Anything near the surface (mostly the dinosaurs) was cooked, but anything living just beneath the surface could have survived.

Citing this post: Urbano, L., 2014. Radiolab: The Extinction of the Dinosaurs, Retrieved April 27th, 2017, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

DNA Models and Games

February 20, 2014

The DNA strand in this board game splits as players end up on different paths based on their choices in the game.

The DNA strand in this board game splits as players end up on different paths based on their choices in the game.

Ms. Mertz’s class is studying DNA–replication, translation, transcription, etc.–and she gave them the option of making a model or creating a game to test each others knowledge. There were some interesting projects:

A DNA strand modeled with the bases represented by colored marshmallows. Toothpicks connect the marshmallows along the backbone of the helices, while  Twizzlers are used to show the bonding across the two DNA strands.

A DNA strand modeled with the bases represented by colored marshmallows. Toothpicks connect the marshmallows along the backbone of the helices, while Twizzlers are used to show the bonding across the two DNA strands.

The quiz questions in this board game are visible to all the players, which allows for more in-depth discussion of the answers.

The quiz questions in this board game are visible to all the players, which allows for more in-depth discussion of the answers.

Helicase (the cotton ball) splits the DNA double helix.

Helicase (the cotton ball) splits the DNA double helix.

Ms. Mertz helps a student with their research project on cloning.

Ms. Mertz helps a student with their research project on cloning.

The study of DNA and heredity offer great opportunities to study probability. In this case, a player has to traverse 80 squares by rolls of a single dice, and then answer a question from a card. If they get the wrong answer they do not advance, but if they pull a Go to Jail card they have to go back to Jail. If there are 20 cards and two of them send you back to Jail, what's the probability of anyone finishing the game?

The study of DNA and heredity offer great opportunities to study probability. In this case, a player has to traverse 80 squares by rolls of a single dice, and then answer a question from a card. If they get the wrong answer they do not advance, but if they pull a Go to Jail card they have to go back to Jail. If there are 20 cards and two of them send you back to Jail, what’s the probability of anyone finishing the game?

Citing this post: Urbano, L., 2014. DNA Models and Games, Retrieved April 27th, 2017, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Blueberries in the Snow

February 19, 2014

Dr. Sansone and a parent volunteer, transplant blueberry bushes into the partly frozen ground.

Dr. Sansone and a parent volunteer, transplant blueberry bushes into the partly frozen ground.

Last weekend was not the optimum time for transplanting berry bushes. The top five centimeters of the soil was still frozen, and the air temperature was below zero Celsius with a cold breeze on top of it. However, we needed to get fourteen blueberry bushes moved, and, with a lot of help from some parents and a couple students, we were able to get the bushes and enough soil laid out to give them a good chance of success when the soil warms up.

Raspberry mounds protected by straw await warmer weather.

Raspberry mounds protected by straw await warmer weather.

Citing this post: Urbano, L., 2014. Blueberries in the Snow, Retrieved April 27th, 2017, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

DNA Visualization

February 13, 2014

Screen capture from R.M's code.

Screen capture from R.M’s code.

Another interesting project that came out of the Creativity Interim was a VPython program that uses the DNA Writer translation table to convert text into a DNA sequence that is represented as a series of colored spheres in a helix.

The code, by R.M. with some help from myself, is below. It’s pretty rough but works.

dna_translator.py

from visual import *
import string

xaxis = curve(pos=[(0,0),(10,0)])

inp = raw_input("enter text: ")
inp = inp.upper()


t_table={}



t_table['0']="ATA"
t_table['1']="TCT"
t_table['2']="GCG"
t_table['3']="GTG"
t_table['4']="AGA"
t_table['5']="CGC"
t_table['6']="ATT"
t_table['7']="ACC"
t_table['8']="AGG"
t_table['9']="CAA"
t_table['start']="TTG"
t_table['stop']="TAA"
t_table['A']="ACT"
t_table['B']="CAT"
t_table['C']="TCA"
t_table['D']="TAC"
t_table['E']="CTA"
t_table['F']="GCT"
t_table['G']="GTC"
t_table['H']="CGT"
t_table['I']="CTG"
t_table['J']="TGC"
t_table['K']="TCG"
t_table['L']="ATC"
t_table['M']="ACA"
t_table['N']="CTC"
t_table['O']="TGT"
t_table['P']="GAG"
t_table['Q']="TAT"
t_table['R']="CAC"
t_table['S']="TGA"
t_table['T']="TAG"
t_table['U']="GAT"
t_table['V']="GTA"
t_table['W']="ATG"
t_table['X']="AGT"
t_table['Y']="GAC"
t_table['Z']="GCA"
t_table[' ']="AGC"
t_table['.']="ACG"

dna=""

for i in inp:
    
    dna=dna+t_table[i]
print dna

m=0
r=3.0
f=0.5
n=0.0
dn=1.5


start_pos = 1
for i in dna:
    rate(10)
    n+=dn
    m+=1
    x = n
    y=r*sin(f*n)
    z=r*cos(f*n)
    a=sphere(pos=(x,y,z))
    #print x, y, z
    if (i == "A"):
        a.color=color.blue
    elif (i== "G"):
        a.color=color.red
    elif (i== "C"):
        a.color=color.green

Citing this post: Urbano, L., 2014. DNA Visualization, Retrieved April 27th, 2017, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

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