Investigating Independent Assorment

INVESTIGATING INDEPENDENT ASSORTMENT: CONSIDERING MORE THAN ONE GENE AT A TIME

Mendel observed the effects of independent assortment when he carried out his dihybrid crosses. When he crossed two plants that bred true for different versions of two traits, the first-generation offspring all displayed the same phenotype (the dominant phenotype for both traits). However, when these plants were crossed, the second-generation offspring included four different phenotypes.

Mendel carefully recorded the numbers of phenotypes among the offspring of many dihybrid crosses. He found that certain combinations of phenotypes among the second-generation offspring occur in a 9:3:3:1 ratio, on the average. We now know that this pattern occurs because genes on pairs of homologous chromosomes are sorted out for distribution into one gamete or another independently of gene pairs of other chromosomes.

Activity

In this activity, you will first access the meiosis tutorial provided by the University of California, Santa Barbara. The tutorial demonstrates the random assortment of chromosomes into gametes. Next you will complete a tutorial quiz about independent assortment. This is part of The Biology Project from the University of Arizona.

Part 1.

Use your browser to go to the meiosis tutorial at

http://www.sumanasinc.com/webcontent/animations/content/independentassortment.html

Use the tutorial to learn how to determine which allele combinations are possible in two or even three trait crosses.

Part 2.

Use your browser to go to the independent assortment tutorial at

http://www.biology.arizona.edu/mendelian_genetics/problem_sets/dihybrid_cross/dihybrid_cross.html

Go through questions 1-9 of the tutorial. If you answer any question incorrectly, review the tutorial material and try again.

When you have completed this much of the tutorial, answer the questions below:

1. What type of gametes will be produced by a plant of genotype AaBb?

The type that will be produced are AB, Ab, aB, ab.

2. What type of gametes will be produced by a plant of genotype aabb?

The type that will be produced is ab.

3. List all the genotypes you would find among the offspring of an AaBb x aabb test cross.

All the genotypes that I found among the offspring are AaBa, Aabb, aaBb and aabb.

4. What is the expected phenotypic ratio of the offspring of an AaBb x aabb test cross? Show the punnett square you would use for predicting the outcomes

.

 

5.What are the genotypic and phenotypic ratios from a AaBb x Aabb mating? Show the punnett square you would use for predicting the outcomes.

6. List all possible gametes from a trihybrid individual whose genotype is RrSsTt.

All the possible gametes from a trihybrid individual whose genotype is RrSsTt are RST, Rst, STr, and rst.

Onion Root Tips Mitosis

Describe the mitosis what the phases looked like. 

ONION ROOT TIPS AND THE CELL CYCLE

In this activity, you will calculate the lengths of the various phases of the cell cycle in an onion root tip. First you will view some slides and graphics of onion root tips provided by the Molecular Expressions Photo Gallery. Then you will complete the online activity provided by the Biology Project at the University of Arizona.

Part 1.

Use your browser to go to Molecular Expressions Photo Gallery: Mitosis

http://www.microscopy.fsu.edu/micro/gallery/mitosis/mitosis.html

Notice in the micrograph at the top of the page that there are cells in a variety of stages. View the onion slides in this section, then click on "mitosis" in the sentence "Learn the steps in mitosis ... " This will take you to a Java tutorial.  Keep in mind what you have learned here as you proceed to the second part of the activity.

Part 2.

Use your browser to go to Online Onion Root Tips at

http://www.biology.arizona.edu/cell_bio/activities/cell_cycle/assignment.html

Begin by reading the description of the five major cell phases. You will need to keep this information in mind during the activity.

Make a copy of the data sheet that appears on the second page. You will need it to answer the questions.

Proceed through the activity, identifying the phase for each cell you are shown. Pay attention to the hints if you misidentify a cell at first.

When you have completed the activity, answer the following questions:

1. What percent of cells were in interphase?

The percent of cells that were in the interphase stages was 56%.

2. What percent were in mitosis?

The percent that was in mitosis was 44%.

3. Which phase of mitosis takes the longest?

The phase that take the longest is prophase.

4. During which stage is the nucleolus visible as a dark spot?

The stage that the nucleolus is visible as a dark spot is interphase.

5. How can you recognize a cell in metaphase?

You can recognize that a cell is in the metaphase stage by knowing that the chromosomes are attached to the kinetochore microtubules begin to align in one phase.

So below are some pictures of other cells that I looked at through the microscope.

 

Stem Cells Webquest

Stem Cells

Research using stem cells is a controversial and often misunderstood area of modern scientific research. In this exercise you will visit the official National Institutes of Health (NIH) website on stem cell information to gain a greater understanding of the fundamentals of this topic.

Activity:

Go to the NIH site on stem cells: http://stemcells.nih.gov/index.asp and click on the Info Center link “Stem Cell Basics.”  Starting with the “Introduction” section, read the information presented.

Use the site’s glossary to find definitions for these important terms:

Cell-based therapies- is the treatment in which stem cells are induced to differentiate into the specific cell type required to repair damaged or destroyed cells or tissues.
Differentiation- the process whereby an unspecialized embryonic cells acquires the features of a specialized cell such as a heart, liber, or muscle cell. Differentiation is controlled by the interaction of a cell's genes with the physical and chemical conditions outside the cell, usually through signaling pathways involving proteins embedded in the cell surface.
Embryonic stem cell line- embryonic stem cells, which have been cultured under in vitro conditions that allow proliferation without differentiation from months to years.
Proliferation- expansion of the number of cells by the continuous division of single cells into two identical daughter cells.
Plasticity-
Pluripotent- the state of a single cell that is capable of differentiating into all tissues of an organism, but not alone capable of sustaining of organismal development.  

Use this site and/or other resources to figure out the basics of what stem cells are. Be able to answer these questions:

1. What are the unique properties of all stem cells?  Explain in your own words what each property means.

So the unique properties of all stem cells are they're capable of dividing and renewing themselves for long periods, they're unspecialized, they can rise to specialized cell type.

2. What are the two main kinds of stem cells used by researchers?  What are the major differences between the two types in terms of their sources and usefulness to researchers?  Give examples of possible uses for each type of stem cell.

The two main kinds of stem cells used by researchers are embryonic stem cells and non embryonic stem cells. The major difference between the two are their different abilities in the number and the type of cells they can become.

3. List some of the diseases that scientists think may be treated using stem cell research and suggest how stem cells might be used to treat each disease.

Three diseases that scientist think may be treated using stem cell research are diabetes, heart disease, stroke, spinal cord injury, and parkinson disease.

4. What are the necessary characteristics that laboratory-manipulated stem cells will need to have in order to be successfully used in cell-based therapies (what will stem cells need to be able to do)?

The necessary characteristics that laboratory-manipulated stem cell will need to have in order to be successfully used in cell based therapies are to create a significant amounts of tissue and they have to be able to survive after they have been transplanted in the receiver.
 

Genetics

If you click on this link you will find some definitions that we learned in the process of getting an understanding of genetics. 

Bladder Cancer

Biology Investigation: Cell Cycle Control, Mitosis, and Cancer



Instructions:

Topic Presentation:

Supplementary Resources:

“Crash Course: Biology” Videos:

Videos By Paul Anderson:

Additional questions to answer:

Things you should make sure you understand:

Instructions:

• Open the presentation.
• Watch the embedded video clips and move through the embedded content.
• Answer the “Questions to answer” at the end of the presentation.
• Make sure you understand the “Things you should make sure you understand”.
• Write down any questions that you have about the material.

Topic Presentation:

click here

Supplementary Resources:

“Crash Course: Biology” Videos:

Mitosis- Splitting Up is Complicated: Biology #12

Videos By Paul Anderson:

“Cell Cycle, Mitosis and Meiosis”

Additional questions to answer:

1. Why does a multicellular organism need to control and coordinate cell division?  What might be the consequences of uncontrolled cell division in a multicellular organism?
2. What does it mean when we say that there are several “checkpoints” that occur during the cell cycle?
3. Give an example of an external signal that regulates cell division and explain how it works.
4. Compare and contrast the functions of proto-oncogenes and tumor suppressor genes.  Give an example of each and explain why mutations in these genes can lead to cancer.

Things you should make sure you understand:

(feel free to ask questions about them in class and/or carry out your own research project)

• The relationship between cancer and cell division.
• How cancer develops in an organism.
• How cancer is treated, and how those treatments affect cancer cells.

-Resources and presentations for this investigation were compiled by Mr. Knuffke so thank him if you run across him online!

Bladder Cancer

So the relationship between cancer and cell division, but both cancer and cell division separate in a very uncontrolled way.

Bladder cancer forms in the tissue of the bladder. The cancer will start in the cells of the inner lining of the bladder. Smoking is supposedly responsible for about half of bladder cancer cases in the USA.

Bladder cancer is treated by surgery- transurethral resection bladder tumor, particle cystectomy and this would be for the early stages. For the later stages it would be a different types of surgery and that would be radical cystectomy. 

Factors for Bladder Cancer

• Age
• Bladder Defects
• Cancer Therapies
• Chronic inflammation of the bladder
• Ethnic Background
• Exposure to certain chemicals
• Family history
• Gender
• Having had bladder cancer before
• Smoking

Symptoms of Bladder Cancer

• Hematuria
• More frequent urinations than usual
• Urinary tract infection
• Sudden urge to urinate
• Pain when urinating
• Pain in the pelvis
• Back pain
• Bone pain
• Unexplained weight loss
• Swelling of the legs

So there are four stages of bladder cancer. In stage one the cancer is in the inner lining of the bladder but it hasn't quite yet invaded the bladder wall. In stage two the cancer has invaded the bladder wall. In stage three the cancer has gone through the bladder wall and has spread to the surrounding tissue. In women this could be the vagina or uterus and for the men it could be the prostate. So in the fourth stage the cancer has already spread to the lymph nodes and other organs such as the liver bones or lungs.

So I ended up using all the videos and presentation you gave us to help us figure out this information, but I just felt like I was able to get a better understanding of it all the with the website Link

Green Human Project

So the company Applied Molecular Evolution is wanting us to create a human that is very energy efficient. This may seem a little difficult but all I plan on doing is comparing the way a human works and the way a plant works. Energy efficient is very important now days with the large amounts of pollutions and growth in population. This experiment can raise some good questions that I will try to answer and solve. Then I will see where I actually go from there.

1. How will light energy be captured? How do plants capture energy and what similar sorts of components would we have to build into our “green human?”  Would photosynthetic humans have to have green skin or could they be some other color? Will additional appendages be required for additional energy-collecting surface area and if so what form should they take? So the human will end up being the color green, since chlorophyll is green and the key ingredient to process of photosynthesis. If we had additional appendages, it could possible be easier for the human to collect some more energy. Since a plant with large leaves is able to collect more sunlight but if we were to lack for the extra arms or legs we could possibly need more light on the skin. So it can absorb and give us the energy we could be lacking. I believe this could make the most logical sense.
2. What sub-cellular structures (organelles) are required for photosynthesis and how does their structure promote the process of photosynthesis? Now this being yet another difficult task of actually being a green human, we would probably have to change our cells to work like a plant cell. By doing so we would need chloroplasts and like plants have, lager vacuoles..
3. How will the energy from energy-carrying molecules be used to create energy-storing molecules like glucose? What types of reactions do plants carry out and what are some of the enzymes that we will need to build into our photosynthetic humans? So as a green human we will need a place to our excess energy. A normal human tends to store all of their extra energy in their fat and if we could think of someone on the green human to store it would be great but instead of it being fat, it would be excess glucose. So thats a whole new problem considering the effects with osmosis so instead we would have to possible store the carbohydrates as glycogen. The way our body will be processing the glucose or sugars and that's where the enzymes come in. So in our body sugars break down in our digestive system quick and easy and since they do so we will not need as much enzymes to break the food down.
4. How will our photosynthetic humans use the energy stores (glucose) that they produce? What are the steps in normal human aerobic respiration that allow for release of energy from glucose? We plan to use the energy as a green human, the same as we do now, but we will produce extra and actually store it for later This is kind of like how you can save some of the solar energy from the panel, that way you have electricity at night. Possibly the green human would need more energy stored to carry out photosynthesis instead of respiration. So other than that it should be the same!
5. What public safety and/or ethical issues will need to be addressed during the completion of this project? Its only logical for there to be problems with an experiment like this for both ethically and safety. Some people wont believe in the idea of doing all of these different tests on humans, while others think it could be great. What if instead of helping global warming, it does the complete opposite. There are a lot of chances to take in this experiment but the outcome can be better then not trying it at all. 

So now that I am done with is Project I can honestly saying it was so bad after all! It's just took a lot of thinking but in the end it was actually kind of fun getting to mess around while being serious, al on the same page. 

PKU Webquest

PHENYLKETONURIA: A METABOLIC DISORDER

Metabolic disorders are genetic diseases that affect the body's ability to perform its normal chemical reactions. Many metabolic disorders result from enzyme defects. Recall that a metabolic pathway is a stepwise sequence of enzyme-mediated reactions. If one enzyme in a metabolic pathway is defective, that enzyme's substrate may accumulate and the pathway may not be completed. This may result in a buildup of harmful substances or a shortage of required molecules.

Activity

In this exercise, you will use the Web links below to gather information about the metabolic disorder phenylketonuria (PKU). Use what you learn to answer the questions at the bottom of the page.

Your Genes, Your Health: Phenylketonuria

http://www.ygyh.org

NSPKU Home Page

http://www.nspku.org

Baby’s First Test (Look up “Classic PKU”)

Newborn Screening in Colorado

Phenylketonuria - The Genetics

http://willroberts.com/pku/

Some possible questions for your research:

1. What enzyme is most commonly defective in people with phenylketonuria?

The enzyme that is most commonly defective in people with phenylketonuria is phenylalanine hydroxylalanine. This is needed to break down an essential amino acid called phenylalanine and foods that contain protein is where this substance is found.

2. What reaction does this enzyme catalyze? (What is the substrate and what product is produced?)
It actually breaks down phenylalanine into tyrosine.
 

3. Describe the symptoms of phenylketonuria.

The symptoms of phenylketonuria are dry, scaly skin (known as eczema), musty or mouse-like body odor, developmental delays, seizures (epilepsy), pale hair or skin, restlessness or fussiness, and smaller than a normal head.

4. What causes the symptoms of PKU, the lack of a substance or the buildup of one? Explain.
The lack of tyrosine causes a build up of PHe and the build of this in other parts puts a stop to the brain developing normally, this also adds to the other symptoms.

5. How common is phenylketonuria? How is it treated?

Phenylketonuria (PKU) appears in every one in ten thousand births. It is treated by being put on a low-protein diet for practically their whole lives