Our Little Friends, Greg and Olga (That poor poor girl!)

Greg and Olga were worried about starting a family because they both had some diseases in their families. They decided to visit a genetic counselor to find out the chances of the diseases showing up in any future children.

Part I: Pedigree Construction

1. I constructed a pedigree for Greg and Olga. Here is what it would look like...

Greg and Olga's Pedigree

Part II: Autosomal Dominant Traits

1) Do autosomal dominant disorders skip generations? 

• Autosomal dominant disorders do not skip generations. 

2) Could Greg or his mother be carriers of the gene that causes myotonic dystrophy?

• No, Greg and his mother don't have the disorder therefore they can not possibly be carriers.

3) Is there a possibility that Greg’s aunt or uncle is homozygous for the myotonic dystrophy (MD) gene?

• No, there is not a possibility. Greg's grandmother would have also had to to be homozygous for the MD gene. You know that she is not homozygous because her husband did not have MD and only two of their four children have the disorder. Therefore Greg's grandmother, aunt, and uncle are all heterozygous.

4) Symptoms of myotonic dystrophy sometimes don’t show up until after age fifty. What is the possibility that Greg’s cousin has inherited the MD gene?

• Well, the good news is, Greg's cousin has a 50% chance of not inheriting the Mytonic Dystrophy gene. The bad news is, she has a 50% chance of inheriting it.

5)What is the possibility that Greg and Olga’s children could inherit the MD gene?

• Happy news for Greg and Olga! There is no chance that their future kids will inherit the MD gene. Neither Greg nor Olga have it so there is a 0% chance of their kids having it. Congrats you guys!

Part III: Autosomal Recessive Traits

1) What are the hallmarks of an autosomal recessive trait?

            -This is what I know:

• The traits are found in the siblings of the person that is affected, but not in the parents or the children of that person (it skips generations).
• Females and males are equally likely to be affected
• It has been found that the recurrence risk for an unborn child of the affected sibling is 25%
• The trait, to the blind eye, may appear as an isolated event in smaller families with only a few children
• The parents of the affected children could possibly be there own "kin". The more rare the trait is in the general population, the more probable it is that inbreeding was involved.

2) What does consanguineous mean? Why is this concept especially important when discussing recessive genetic disorders?

• Consanguineous is a term to describe being related by blood or family. This is important when discussing these genetic disorders because consanguineous mating causes a higher risk of passing the ressesive disorder. 

3) What is it about the inheritance pattern of factor VIII deficiency seen in Greg and Olga’s pedigree that point toward it not being an autosomal recessive trait?

• The inheritance pattern of Factor VIII deficiency points more toward it being a sex-linked trait instead of autosomal recessive, because it is only seen in males on the pedigree.

Part IV: Sex-Linked Inheritance 

1) What are the characteristics of X-linked recessive inheritance?

• Males are more likely to be affected than females
• All the affected males in a family are related by their mothers
• The trait is usually passed down from an affected grandfather to his daughter, who then carries the trait and passes it on to 50% of her sons.
• The trait is never passed directly from father to son 

2) Why does a son never inherit his father’s defective X chromosome?

• A son will always be lucky enough to never inherit his father's defective X chromosome because he inherits Y from his father, not X

3) What is required for a woman to display a sex-linked recessive trait?

• The woman must be homozygous for the sex-linked recessive trait in order to display it.

4) Return to the pedigree drawn earlier for Greg and Olga; mark those persons who are carriers of the factor VIII deficiency gene.

• The people now labeled with the orange dot in the pedigree, are carriers of the factor VII deficiency gene.

5) What is the chance that Olga carries the gene for factor VIII deficiency? Calculate the probability that she will pass it to her offspring. Will male children be affected in a different way than female children?

• There is a 50% chance that Olga has the gene for Factor VIII deficiency. If she does, than there is also a 50% chance that she will pass it on to her children (so half of her children will probably have the gene as well) The male and female children will both be affected in the same way because they both have the same chance of inheriting it.

6) What is the chance that Greg carries the factor VIII gene? Can he pass the gene on to his sons? His daughters? How will each be affected?

• Sadly, it is a 100% guaranteed that Greg carries the factor VIII gene. He can not pass this on to his sons because they inherit the Y chromosome from him- not the X chromosome. Greg can pass the gene onto his daughter, who will then be a carrier and could pass it onto her children.

To get to the website about Greg and Olga, click here- http://www.sciencecases.org/sickness_and_health/sickness_and_health.asp 

Please Let This Raise My Grade For Data Analysis! :)

Yeah It's a Really Big Word!

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Our Photosynthesis "Dry Lab"! Oh The Excitement! :)

So I guess this week we went backwards.(Actually this last week- I forgot to post this. Oops) Instead of doing an experiment and writing down the observations, Mr. Ludwig gave us a set of observations and we had to write the procedure that went along with this experiment given. I was very confused at first but then I looked at other blogs and worked on it with a friend so this is our (mine and Chapin's) Photosynthesis "Dry Lab." Enjoy!



Materials

• Distilled Water
• Bromothymol Blue (BTB)
• Aquarium Snail
• Elodea
• Large Test Tubes
• Light
• Dark Space

Procedure

1. Put 15 ml of water and 15 drops of  BTB in a large test tube and let it sit for 3 hours under light. Record your observations.
2. Put 15 ml of water, 15 drops of BTB, and an aquarium snail in a large test tube and let it sit for 3 hours under light. Record your observations.
3. Put 15 ml of water, 15 drops of BTB, and a elodea (funny plant) in a large test tube and let it sit for 3 hours under light. Record your observations.
4. Put 15ml of water, 15 drops of BTB, an aquarium snail, and an elodea in a large test tube in the light for 3 hours. Record your observations.
5. Repeat Step 4 procedure but put it in the dark for three hours and let it sit. Record your observations.

(If your water doesn't turn blue after 15 drops of BTB keep putting drops in until it turns blue)


Observations:
Water plus BTB is blue-green.
         Water is neutral. It changes to the color of the substance that is put in it.


Water plus BTB and an Aquarium Snail is yellow in light.
          Animals respire (breath) and they let Carbon Dioxide out. Carbon dioxide in water produces carbonic acid. When there is acid in BTB and water it turns to yellow.


Water plus BTB plus elodea is blue-green in light.
          Green plants respire. Then they photosynthesize and use the Carbon Dioxide. The plant keeps the water from acid it stays a neutral at the blue green color.


Water plus BTB plus a snail plus elodea is blue-green in light.
          The plant and snail respire. But the plant photosynthesizes and uses the Carbon Dioxide so it turns to blue green and there is no carbonic acid.

Water plus BTB plus a snail plus elodea is yellow in dark.
          The snail and plant respire. Since there is no light the plant can't photosynthesize. The carbon dioxide is still in the water so it stays an acid and the color stays yellow.


Conclusion:
When BTB is added to water it turns yellow because Carbon Dioxide and water mixed together make a carbonic acid. It stays blue with just water because water is a neutral.

Photosynthesis

This is the poster that Sierra, Chapin, and I made on Photosynthesis and how plants make the magic happen.

A Little Something About What You Need

     So I am sure you have heard a lot about carbs and how they are awful for you.  You probably especially hear this from those people whose main desire in life is to be super skinny. I bet your thinking, "But all the delicious food has carbs in it! Am I not supposed to be eating anything that tastes good?" That's a disappointing thought! Well have no fear! I am hear to tell you all about these bad boys that they call carbs.
     Carbohydrates (the more technical term for carbs) are a macromolecule. Carbohydrates are used as an immediate energy source in living things but they also give structure to a variety of organisms. Most carbohydrates have the ratio of 1:2:1 for carbon to hydrogen to oxygen.

     Glucose is an example of a carbohydrate, but not just any carbohydrate, a monosaccharide to be specific. A monosaccharide is a simple sugar that canot be broken down by hydrolysis. Monosaccharides have this crazy name because "monos" means single and "sacchar" means sugar. Get it? It's made of only one single sugar; they are a simple sugar. Yeah, well now that you hopefully got that down I can tell you that these simple sugars can have a backbone of three to seven carbons. The molecular formula is some multiple of CH2O. Which means...that with every carbon item it is bonded to a H and a -OH molecule. However, this is not always true, there are a few exceptions. This is just the basic formula. Glucose has six carbon atoms and therefor called a hexose. its molecular formula is C6H12O6. Ribose, on the other hand, is made up of five carbon atoms and therefore called a pentos. But usually these monosaccharaides dont stay that way for long.

     When two monosaccharides combine in a dehydration reaction  you get a disaccharide. For example when you combine glucose and fructose (two monosaccharides) you get the disaccharide of sucrose, also known as table sugar.  Sucrose is the form of sugar that is transported in plants. Another disaccharide, lactose, is made when glucose and galactose are combined. I'm sure you have heard of a few people who are lactose intolerant. This means that that person cannot break down the lactose disaccharide.
     Polysaccharides are the next step up. Polysaccharides are polymers(macromolecule consisting of covalently bonded monomers) of monosaccharides or a bunch of monosaccharides combined together. These carbs can also be called complex carbohydrates.  Some types of polysaccharides are used as short-term energy storage. These can be used as storage because they are not soluble and they are bigger than sugar. because of their large size they can't pass through the plasma membrane. When you need energy the pollysaccharide is broken down to release its sugar molecules.

These are polysaccharides that are found in  plant cells

     So in other words these carbs are not some awful things that you should steer clear from. You actually do need them. Just make sure you are not consuming too much more than you need.

Oh The Joy of Fluid Mosaic Models

   A fluid mosaic model is a model for the plasma membrane based on the changing location and pattern of protein molecules in a fluid phospholipid bilayer. The proteins in the model are just scattered about the membrane. This model was introduced in1972 by S. Singer and G. Nicolson.
   The plasma membrane separates what is inside the cell and what is outside. It controls what enters and exits to help the cell maintain a steady internal environment.
   There are many complex structures that make this what it is.

   The microfilamants help the cytosceketon to maintain its shape, but still allow some cells to move.
   The phospholopids make up the cell membrane. The are made of two major parts: the head and the tail. The head is the polar/hygrophillic phosphate groups. The tail shows the nonpolar/hydrophobic fatty acid chains of phosphate. The heads of the phospholipid face where the water is found, to the inside and the outside of the cell. The phospholipid tails face towards each other in between the heads.
   A glycolipid is a lipid that has sugar attached to it. This serves as a marker for cell recognition and provides energy.
Cholesterol  helps by stiffening and making the membrane stronger. This helps control the fluidity.
 
   Proteins!
There are many different kinds of proteins.
Channel proteins assist with the passage of different molecules through the membrane. They contain a channel that allows molecules to simply move from one place to another.
Carrier proteins also help with moving things across the membrane. They combined themselves with a substance and assist it in moving across the membrane. By transporting potassium and sodium ions across the cell membrane of a nerve it makes nerve conduction possible.
Cell recognition proteins  are glycoproteins. These help the body in recognizing when it is being invaded by pathogens(a disease-causing agent) so it can react with an immune reaction. If we didn't have these pathogens would be able to invade our body without restrictions.