This site was originally created for my kids and their cousins, because we did science together. We eventually added more friends and I ended up having science classes for five years. I am no longer adding to the site (since 2014), but will leave it up for others' use. (I do post to facebook occasionally if I come across something to share.) =)

Please do not email, asking me to post your website link, or to review something to put on my site. Any resources posted on this site are things I had found on my own during my regular searching for material I needed at the time, and liked it well enough to post here. There have never been any affiliates on my site, and as it is no longer active, would not be worthwhile at this point.
Thank you!

Balancing Chemical Equations

I just had to share!  A new favorite video!  (Another being this one on Unit Conversions)

I would suggest setting aside about 25 minutes and have paper and pencil handy.  After the first few when you get the hang of it, pause the video and write out each new equation.  Pause often to study the equation and see if you can figure out what the next step should be.  Follow along and write it out as you go.  =)

►Check out Tyler DeWitt's YouTube channel for more videos.  See his playlists, especially the one on Unit Conversions.

This video is now linked and/or embedded in the Chemistry post, and Biology Module 5 Part A and Part B.

Chemistry 101 Tab


I needed a place to save some links and notes for myself so that I would remember what things I'd come across, so I decided to share even though it's not very thorough.

See top for the tab!  =)

Colored Fire!! =)

An exciting activity to test for elements!!
http://chemistry.about.com/od/funfireprojects/a/coloredfire.htm

Let your students do a little research (with direction as needed) on the colors each will produce (John Hudson Tiner's Exploring the World with Chemistry, ch 5, will help if you have it). Or just show them the website. 
Might want to first see what materials you're able to obtain, and which elements your child has learned, then go from there. 


--Chemistry 101 (Wes Olson), chapter 6 mentions when elements are exposed to fire, their gases give off a distinct "fingerprint" of color. 

--We will be reading Tiner's ch. 5 along w/ Chem 101, ch. 3 because of the scientists mentioned and what they discovered. This will be a good time for us to do this experiment!   And watch some Periodic Videos as well!!  http://periodicvideos.com/

(I also want to be learning some of the elements ahead of Chem 101 because he introduces them almost all at once, and because, well, I just don't want to wait, lol.)

More tips about colored fire here: http://chemistry.about.com/cs/howtos/a/aa052703a.htm

We will probably just sprinkle the substance on the fire, but from something with a long handle. 

You can also have your child to do a lab report on this.  Have him fill out the initial part of a lab report, including materials, his predictions, etc (make a chart), then fill in what actually happened and if he had better results for some substances than others, and why he thought that happened.
If you're not sure how to do a lab report, instead of copying one person's method, the best way to learn something is to google and compare several samples so that you know what you want.  =)


Any ideas or thoughts on this experiment?


Biology 101, Chapter 7, The 6th Day – Biology History, Cells, Genetics [post 3/3]

Spud-Doodles!
Blog Posts for Chapter 7:
• Post 1/3 Cells
• Post 2/3 - DNA
• Post 3/3 - Genetics


In Addition to Biology 101:
• Apologia Biology Exp. 8.1, Making Your Own Earlobe Pedigree
• Apologia Biology Exp. 8.2, A Dihybrid Cross
• Apologia Biology Exp. 8.3, Sex-Linked Genetic Traits
• Build-a-Spud Workshop using these Spud Genes.
My directions, and thanks to Mr. McClung for the original idea and directions.
• Extra Punnett Square worksheets in class - some choices are here and here.

Other Study Links:
► Pass the Genes, Please - Help the Melonheads pass their genes on to their little Melvin.
► Genetics Practice Problems - Answer questions about genotypes (such as bb, Bb, or B and b, or b and b, etc), and fill in Punnett squares.  (Put the male genes at the top of the Punnett square, and the female genes on the left.)
►Listen to more about Gregor Mendel's experiments at this link from HippoCampus.org.  There are five segments, numbered at the top.
This link will only be available until June 24, 2014.  =(



Naturally after learning how meiosis provides the way for 
us to all be so different, now we learn about genetics! =)



Genetics



a. Mendel's Experiments

Self-pollination - when a plant pollinates itself.  Usually, the stamen that holds the pollen (in the anther) must be taller than the pistil (where the stigma is) so that the pollen can fall to the stigma.  Sometimes this is not necessary as you can see in a video below. 
Flower dissection from last year.

(Source)


Cross pollination is more common than self-pollination.
Cross-pollination - when pollen is delivered from a flower to a different plant.  This happens frequently with bees, or when the wind blows the pollen, or by other means.

(1) Pollination, Plants, and Insects - Cross-Pollination





(2) Plant Reproduction: Methods of Pollination - Self-pollination





(3) Mendel Single Trait Experiments
Gregor Mendel used pea plants because they do not lend themselves to cross-pollination naturally.  Gregor Mendel did this by hand.
Genes are made up of segments of DNA found on larger pieces of DNA called chromosomes.








b. Terminology

(4) Genotype (Terminology)
Genotype is the combination of alleles an organism has.  Genotype is the "type o' genes" you have (TT, Tt, or tt). It is your genotype that determines you phenotype (which is the trait you can actually see).




You need to know this terminology:

Genes vs. Alleles
(uh-LEELs) hear pronunciation
A gene is a section of DNA that codes for a particular trait.
A gene comes in alleles (choices) that are different forms of a particular trait.
There are hundreds of genes on each chromosome!

Alleles are different versions of the same type of gene.

The gene for hair color can have blond alleles, brown alleles, etc, and the gene for eye color can have green alleles, blue alleles, brown alleles, etc.  Plants can be tall or short.  Flowers can be different colors.  Lots of different alleles for any particular type of gene.


We're all allele different.  =)


Allele vs. Trait

Alleles make up a trait.  The "blue eye" trait will contain the alleles b and b (one contributed from each parent).  The "brown eye" trait will contain the alleles B and B, or B and b. (B is dominant over b, so even though b can be present, B will make a person have brown eyes.)
Two alleles make up the blue eye trait [bb] or brown eye trait [BB or Bb].



Dominant vs. Recessive
Alleles can be dominant or recessive.  If you receive one allele for brown eyes and one for blue eyes (one from each parent - Bb), you will have brown eyes since brown eyes are dominant over blue eyes.  Tall plants are dominant over short.
So when both dominant and recessive alleles are present, a dominant allele will always be seen over a recessive allele.

Recessive alleles (blue eyes, etc.) can be seen in a person if there are only recessive alleles for that trait present on your DNA.  [bb]

Dominant alleles are always represented by a capital letter, and recessive alleles are represented by a lowercase letter. [Bb or BB]



Homozygous vs. Heterozygous
(home-oh-ZY-gus, het-er-oh-ZY-gus) Hear pronunciations here and here.
Alleles can be expressed in two different ways.  For each trait, you always have an allele from your Mom and an allele from your Dad, so there are two alleles present for each particular trait.  Your Mom and Dad got an allele from each of their parents for each particular trait.  Your children will have one allele from you and one from your spouse for each trait. 

Homozygous alleles are the same.  Homo means same; zygous comes from zygote, which is the initial cell formed when two gamete cells are joined.  (one from each parent)
So homozygous alleles will either be represented with two capital letters, or two lowercase letters.
TT can mean a tall plant, which is dominant, and tt can mean a short plant, which is recessive.

Heterozygous alleles are different.  (Different versions of the same type of gene)
Heterozygous alleles will be represented with one capital letter and one lowercase letter.
Bb means there is one allele for brown hair present and one allele for blond hair present.  But since brown is dominant, the person having these alleles will have brown hair.  This person may later have a child with brown or blond hair, depending on which allele is contributed from the other parent.

►So if a genotype is homozygous, we know the letters of the genotype are the same, and either they are both capital or both lowercase.  
If a genotype is heterozygous, there is one capital and one lowercase letter. 


Heterozygous and homozygous are adjectives.
Heterozygote and homozygote are nouns.



                                              This cracks me up!! =D                                 (source)



Genotype vs. Phenotype
--If you are asked to give the genotype, you will give the letters to represent the alleles.
BB, Bb, or bb, etc.
Genotype is the alleles inside you.
--If you are asked for the phenotype, you will use words to explain a visible characteristic.
Green eyes, a tall plant, a purple flower, etc.
Phenotype is what you see.

♦A genotype that is homozygous dominant means the letters are the same, and they are capital.  BB, TT, etc.
♦A genotype that is homozygous recessive means the letters are the same, and they are lowercase.  bb, tt, etc.
♦A genotype that is heterozygous means the letters are different, and there is one dominant allele (capital) and one recessive allele (lowercase).  Bb, Tt, etc.



Genotypes vs. Gametes vs. Zygotes
Genotypes:  TT, Tt, or tt, or PP, Pp, or pp.  Same letters.
Gametes:  TP, Tp, tP, tp.  Different alleles form a gamete (sperm or egg)
Zygotes:  Form when 2 gametes fuse during reproduction.

To clarify differences, here is an Example:
Gene - eye color
Allele - B or b
Genotype - BB, Bb, or bb
Trait or Phenotype - brown or blue eyes







c. Punnett Squares

(5) Gregor Mendel's Punnett Squares


Example 1
The homozygous bean in this example is homozygous
recessive
because the letters are lowercase.


 Example 2


(6) Introduction to Heredity - Heredity and classical genetics; dominant and recessive traits; heterozygous and homozygous genotypes.




Filling in a simple Punnett Square is just showing the different genotypes that 
are possible from the alleles of both parents through the process of meiosis.  


Now go back and read all the terminology definitions again.
I think you'll understand them better now.  =)



    Practice #1:
Pass the Genes, Please - Help the Melonheads pass their genes on to their little Melvin.
Genetics Practice Problems -
   Do the first 2 sections:
• "Monohybrid Cross" (comparing only one allele from each parent), and
• "TestCross" (crossing an unknown genotype and a homozygous recessive [dd] genotype to determine what the unknown genotype is.)
Read carefully!  You will see in TestCross, the first question tells you the female dog is deaf [dd], but you will see that the owner isn't sure if the hearing male dog is DD or Dd.
--Answer questions about genotypes (such as bb, Bb, or B and b, or b and b, etc), and fill in Punnett squares.  (Put the male genes at the top of the Punnett square, and the female genes on the left.)

►Remember, this is a computer, so it will want things in a certain order.
When you check your answers, DO NOT CHECK THE BOX that says "prevent this page from creating additional dialog."  This will cause the program to stop telling you whether an answer is correct or not.  And if you refresh your page, it will remove all previously done answers. =(







d. More Complex Crosses 

monohybrid cross - a cross between two individuals, concentrating only on one definable trait
dihybrid cross - a cross between two individuals, concentrating on two definable traits (this gives four possibilities)

If one were talking about the two traits of color of a plant -- purple or white, and the height of a plant -- tall or short, there would be four possibilities.
(1) A Tall Purple plant
(2) A Tall white plant
(3) A short Purple plant
(4) A short white plant

This would involve a dihybrid cross that concentrates on two definable traits.
The possibilities listed above would be these gametes:  TP, Tp, tP, tp.

►These ↑ are not genotypes; they are gametes.  
Genotypes are TT, Tt, or tt, or PP, Pp, or pp.  (Same letters.)


(7) Biology - Punnett Squares - simple (monohybrid cross) to more complex (dihybrid cross).  And I like that his use of the correct terminology will get you more familiar with it.

►At 5:45, he is talking about a "standard 9:3:3:1 ratio." 
You can see that the gametes across the top and on the side of the Punnett square are the same.  In a dihybrid cross (4x4 Punnett square) with mom and dad having identical gametes, this will always result in 9 offspring that are the same, two sets of 3 that are each the same, and one in the bottom right corner that is unique.  And if you write the mom's and dad's gametes in the same order, you will see this exact pattern on your grid.




(8) Dihybrid - Dihybrid Cross, meaning comparing not one, but two traits.

At 5:30, also note that three of the pups are carriers for a spotted and/or red coat.
Pup #2 is a carrier for a spotted coat, pup #3 is a carrier for a red coat, and pup #4 is a carrier for both a spotted and a red coat.
If any of these dogs mates with a dog who is homozygous recessive (ss or bb) for these particular traits, they can pass on these recessive traits to some of their pups.




(9) Punnett Square Fun - dihybrid crosses; independent assortment; incomplete dominance; co-dominance and multiple alleles.




Blood Types
Type AB blood is the universal recipient -- it can receive from types O, A, B, or AB.
Type O blood is the universal donor -- it can donate to types O, A, B, or AB.
So Melanie with type B blood or Kathy with type A blood can both donate to Jill with type AB blood.
But Jill cannot donate to either Melanie or Kathy.
Valerie with type O blood can donate to all three girls, but cannot receive from either of them.
(This is a simple explanation and does not include Rh)




(10) A Beginner's Guide to Punnett Squares - actually pretty fast, so a good review.
►At 06:50 --he shows a mistake that one might make with dihybrid crosses.  Watch out! =)




    Practice #2:
► Genetics Practice Problems 
Read and Do the 3rd and 4th sections:
• "Incomplete Dominance" (when two dominant traits blend), and
• "Dyhibrid Cross" (comparing not one, but two traits, resulting in 4 possibilities.)
Read carefully!  
--Answer questions about genotypes (such as bb, Bb, or B and b, or b and b, etc), and fill in Punnett squares.  (Put the male genes at the top of the Punnett square, and the female genes on the left.)

►Remember, this is a computer, so it will want things in a certain order.
When you check your answers, DO NOT CHECK THE BOX that says "prevent this page from creating additional dialog."  This will cause the program to stop telling you whether an answer is correct or not.  And if you refresh your page, it will remove all previously done answers. =(







e.  Pedigrees 

(11) Pedigree Instructions, Part 1





(12) Pedigree Worksheet, Part 2








f.  Sex-Linked Genetic Traits 

autosomes - chromosomes that do not determine the sex of the individual
sex chromosomes - chromosomes that determine the sex of the individual

Remember, humans have 23 homologous pairs of chromosomes.  Only one pair is the sex chromosomes; the other 22 are autosomes.

The female XX pair of chromosomes are perfectly homologous.  The male XY pair of chromosomes are not perfectly homologous.  There are fewer genes on the male's Y chromosome than there are on the X.
Sex-linked characteristics are not written in the same way you have learned so far because we need to distinguish that the Y chromosome does not have certain traits that can only exist on the X chromosomes of
males and females.
So we write both the X's for the female with the allele as a superscript, and only the X chromosome of the male (and not the Y) will have a superscript.  A superscript is written like an exponent, like this: X¹X² and X³Y, but instead of numbers the allele is either a capital or lowercase letter. 


(13) Sex-Linked Traits





(14) Sex-Linked Genes





(15) Chromosomes Crossing Over - Linked Genes








g. More about Genetics 

(16) Polygenetic Inheritance 
Around 1 minute, notice he says IF melanin production were controlled by one gene...





(17) Co-dominance - Incomplete Dominance





(18) Recessive Single Gene Disorders (cystic fibrosis, sickle-cell anemia)




There are at least five means by which genetic abnormalities occur.
1.  autosomal inheritance 
2.  sex-linked inheritance
3.  mutation
4.  changes in chromosome structure
5.  changes in chromosome number

None are truly beneficial.


Biology 101, Chapter 7, The 6th Day – Biology History, Cells, Genetics [post 2/3]

We made DNA! =)
Blog Posts for Chapter 7:
• Post 1/3 Cells
• Post 2/3 - DNA
• Post 3/3 - Genetics

In addition to Biology 101:
• Apologia Biology Exp 7.1, DNA Extraction
Here are instructions if you don't have an Apologia Biology book, and a video.
• Have Your DNA and Eat it Too! (click the pdf links), Our class has done this twice (diff students), so even tho I have 3 new kids, I have 3 who have already done this so we aren't doing it this year.

Other Study Links
 DNA Extraction Virtual Lab.




2. DNA

Four criteria for life:
If something fails to meet even ONE of these, it is not alive.
  1. All life forms contain DNA.
  2. All life forms can take energy from their surroundings and convert it to usable energy for themselves.
  3. All life forms can sense and respond to changes.
  4. All life forms reproduce.
DNA - deoxyribonucleic acidHear pronunciation.  Click on the little speaker.


Apologia Biology Experiment 7.1, DNA Extraction
My previous biology class did this experiment about 3½ years ago.  (See our results)
If you don't have an Apologia Biology book, here are instructions (with explanations of why), and a video below.  (I always like to look at several sources to get a good idea of how and why to do things.)
(1) Pea DNA Extraction


►And just for fun, you can try this DNA Extraction Virtual Lab.
►Read how another blogger's class did this experiment.  Her posts are always fun to read! =)

Of course this DNA is in clumps, or we would never be able to see anything.
In fact, it takes a powerful microscope to even be able to see the chromosomes, which are long strands of DNA in the nucleus that are coiled up and compacted.  See image. (source)



(2) DNA Structure
Note that A and T are linked together, and C and G are linked together.  These letters represent the names for the nucleuotides in DNA.  In DNA, Adenine always links to Thymine, and Cytosine always links to Guanine.
Apples in a Tree, Car in the Garage.  A-T, C-G




How proteins are made from DNA
All the writing below and three videos make up this section.

Part 1: Transcription of DNA
"Synthesis" means the making of or production.  
Cells synthesize, or make, proteins that result in the traits that DNA gives us.  The cell's genes determine what kinds of protein a cell will make, which determines the job of that particular cell. 

(3) Transcription and Translation Overview
polypeptide is a chain of amino acids.  Poly means many.



scribe is someone who writes down a copy. You can see the word scribe in transcribe, and script in transcription. Transcription means to copy or transcribe.  

Something called RNA is what helps make the copy of DNA, which is in the nucleus of the cell.   RNA looks like DNA, but it ends up being only a single strand of nucleotide bases. 

The differences between DNA and RNA are:
►DNA: has nucleotide base pairs of cytosine & guanine, and adenine & thymine.
(Apples in a Tree, Car in the Garage.  A-T, C-G)
►See diagram of DNA strand. (source)  

►RNA: has individual nucleotide bases of cytosine, guanine, adenine, and uracil, but they are not in any particular order yet.  They will match up to corresponding DNA nucleotides so they will be in the correct order for transcription (copying)


►►DNA vs RNA image (source)◄◄ Read below↓

--There are two nucleotides that are different - uracil (in RNA), and thymine (in DNA).
Uracil in RNA will match up to adenine in DNA.  
Adenine in RNA will match up to thymine in DNA, so A-U, and A-T.
(For RNA, remember Apples Under the tree) 

DNA: has deoxyribose (on the "rail" of the "ladder").
RNA: has ribose. 
DNA: is twisted in a double helix of paired nucleotides.
RNA: usually in a single strand of joined nucleotides.

►See diagram of DNA and nucleotides (source).
Only a certain section of DNA will be copied.  As this section of the DNA strand unwinds, individual RNA nucleotides match up to compatible DNA nucleotides and take a "negative snapshot" of the DNA code.  
For example, if the DNA has a nucleotide of guanine, an individual nucleotide of RNA cytosine will match to it.  If the DNA has a nucleotide of adenine, an individual nucleotide of RNA uracil will match to it.
Before, the RNA nucleotides were individuals, and not in a strand since they had to match up to the DNA in the correct order.  Now they are a "negative" copy of the DNA, and will be used by the ribosome to make a protein.
►This is copying, or transcribing the DNA code. 


Part 2: Translation of DNA
After the RNA "negative" of the DNA is made, the RNA takes this negative out of the nucleus and into the cytoplasm to a ribosome.  Because of this, it is called messenger RNA, or mRNA.  
Near the ribosome is a different kind of RNA called transfer RNA, or tRNA.  This tRNA contains a special sequence of three nucleotides called an anticodon.
(A special sequence of three nucleotides on mRNA is called a codon.)
The codon and anticodon aren't just any three nucleotides, but certain various combinations.

Transfer RNA strands will link to a messenger RNA strand on a ribosome in order to make a protein chain.
Here is how:
The tRNA is already bonded to an amino acid, but only a certain type of amino acid will bond to a certain sequence of three nucleotides in the mRNA.
For example, if the anticodon (a three-nucleotide sequence on tRNA) is made up of guanine, adenine, and adenine, the tRNA is bonded to the amino acid leucine.  This anticodon will only link to a portion of mRNA that has a codon with the sequence of cytosine, uracil, and uracil.  
Each codon (3-nucleotide sequence) on mRNA attracts a specific amino acid. 
So then the tRNA links up to the portion of mRNA that will accept the anticodon that is on the tRNA.

After the tRNA links up to the mRNA, the amino acids on each of the subsequent tRNA anticodons bind together one by one to make a protein. 
►The chain of amino acids that make a protein is called a polypeptide. (poly- means many)

(4) From RNA to Protein Synthesis - how proteins are made



Learn the difference between mRNA codon and tRNA anticodon, and how a chain of amino acids form a protein.  A stop codon is a special codon that signals the stopping point for translation.
Learn which codon is the starting point for Translation (which 3 letters).
(5) Protein Synthesis: Translation Process



And that is how proteins are made from DNA




(6) DNA Double Helix
How one man realizes through studying DNA that only God could have made all this! =)
"Without DNA there is no self-replication, but without self-replication, there is no natural selection. So you can’t use natural selection to explain the origin of DNA without assuming the existence of the very thing you’re trying to explain!"






Two Types of Cell Reproduction:

A) Mitosis - asexual  reproduction of cells

Mitosis is the growth of new cells, either to replace damaged cells like when you have scraped your arm, or for a growing child, or an unborn baby as it grows.
The replicated cells are identical.  Skin cells replicate skin cells; muscle cells replicate muscle cells, etc.
This is asexual (nonsexual) reproduction.

(7) The Cell Cycle and Cancer - how cells multiply by Mitosis











(9) How DNA is Packaged  After DNA that is in the nucleus duplicates itself into identical sister chromatidsthen it coils up into chromosomesThe X shape you may be familiar with.





(10) Mitosis  He says, "having already replicated..." Because before Mitosis begins, the DNA that is in the nucleus must duplicate itself into identical sister chromatids, then coil up into chromosomes.






(11) Mitosis Animation - also G1, S, and G2 that occur during Interphase.






B) Meiosis - the purpose of meiosis is sexual reproduction. 

-All living things have different numbers of chromosomes.  An onion has 16 chromosomes in each cell; a horse has 64 in each cell; and a carp has 104 in each cell.
--Humans have 46 chromosomes in each cell.  The chromosomes are in pairs, so humans have 23 pairs in each cell. 

Meiosis:  
The cool process of meiosis is why all humans do not look alike.  =)
Each pair of chromosomes determines many different traits (hair color, hair texture, curly, straight, etc, just to name a few).  There are hundreds of genes on each chromosome!  When parents have children, they contribute one chromosome from each pair, which "cross over" with each other to form new combinations.  The results of crossing over are random, and give more possibilities for each trait a child will have.  Since there are many, many kinds of traits, the possibility of having a child who doesn't look exactly like a parent is great.


Things to know:
--When a cell's chromosomes come in pairs, it is called a diploid cell.  XX, XX, etc.
--Cells with chromosomes that are not in pairs are called haploid cells.  A haploid cell has only one representative of each chromosome pair.  X, X, etc.
Cells can have 23 pairs of chromosomes, or 23 chromosomes, depending on what phase the cell is in.

Each pair consists of similar types of chromosomes, and therefore they are called homologous chromosome pairs, or homologous pairs.  Homo- means same, but homologous means similar, but not identical.

Each chromosome that is in a pair is attached to its sister chromatid (its duplicated chromosome), giving them their X shape.  Two sets of these make a pair of similar, homologous chromosomes.  XX.
--The 23rd pair of chromosomes are chromosomes that determine sex.  In a female these are both X chromosomes, or XX, but in a male, they are XY.  So in males, the 23rd pair is not homologous.
►See image of Human Chromosomes


Mitosis results in 2  identical diploid daughter cells, 
and meiosis results in 4 genetically different haploid cells.


►►These videos only show a few pairs of chromosomes in the cells, but know that there are 23 pairs, all exchanging information to produce varied traits.

(12) Meiosis - This is why parents can have children who look so different from one another. 








Mitosis results in 2 identical diploid daughter cells, 
and meiosis results in 4 genetically different haploid cells.

So what happens to the extra haploid cells?  In females, randomly, one of the gametes (eggs) takes up most of the cytoplasm and organelles.  As a result, what gets produced are 3 tiny gametes and one large gamete called the egg.  Only the large one will function properly, and that is the one that gets successfully fertilized by the male gamete (sperm).  The others, if fertilized, will quickly degenerate and die.
►The haploid sperm cell and haploid egg cell fuse to form a diploid cell with 23 pairs of chromosomes, totaling 46.
►This diploid cell, now called the zygote, will begin to multiply and produce many cells by mitosis, forming a baby.  =)


(14) Phases of Meiosis  2²³ = 8,388,608 possibilities! WOW!






After you understand meiosis, here is a fun video to watch.  =)
The DNA first coils up into chromosomes (see image).