Self and Unit Evaluation

1.  What were the three aspects of the assignments I've submitted that I am most proud of?

Preparation, review, concept. Although I think the final product was not fully representative of these aspects. The course required the pulling together of varied assignments of different formats which I feel was a learning experience in many areas.

2.  What two aspects of my submitted assignments do I believe could have used some improvement?

Preparedness, word processing familiarity are the two aspects that  detracted from focus in other areas. 

3.  What do I believe my overall grade should be for this unit? 

I think I met the basic requirements. Overall I'd say B.

4.  How could I perform better in the next unit?

Being more familiar with the format should give me more of a flow with the material.

     At what moment during this unit did you feel most engaged with the course?

    This was a little surprising to me but it was working with the lab model. For me it more of  a relaxed way of approaching the       topic.   

   At what moment unit did you feel most distanced from the course?
     I was a little overwhelmed in the beginning.  
   

     What action that anyone (teacher or student) took during this unit that find most affirming and helpful?
     Everyone at the learning center was extremely helpful. 
 
     What action that anyone (teacher or student) took during this unit did you find most puzzling or confusing?
     I think it was little difficult starting out because of my own apprehension. 
 
What about this unit surprised you the most? (This could be something about your own reactions to the course, something         that someone did, or anything else that occurs to you.) 
        The use of a blog site. The versatility in visual presentation. 

www.foxnews.com

To Grow or Not to Grow

Can growing of genetically  modified crops coexist with non genetically modified crops and what are the potential dangers. Some scientists say that not enough testing has been done and the affects are often cumulative. Biotech corporations suggest that the differences are minimal. However, some in the scientific and environmental community have different conclusion. One such explanation stated that organisms created from gene-splicing are different in their genetic make up and interact to their surroundings differently on a cellular level. The genes  behave in a way like a virus. "The foreign gene acts independently of cellular controls, uncorrelated with the other genes".  

In reference to controlling contamination "the official advise of  the UK is that there should be a separation of 50 meters".  There are just as many differing opinions. Certain governments and biotech corporations believe with the proper controls contamination can be minimized. A study made in Mexico discovered GM corn contamination as far as several hundreds of miles. "Mexico doesn't allow genetically modified cultivation" and has concerns over biodiversity and preserving it's "unique strains of maize".  Some opponents of  genetically modified crops say it should never be allowed to be cultivated on a large scale.

One ecologist provided five reasons why genetically modified crops should not be grown. His issues were consumer choice, potential health risk, the loss of small scale farming, corporate control of food supply, and environmental issues. Regards to consumer choice, some say consumers don't want to eat genetically altered food. One incident that caused alarm was the finding of corn taco shells that contained genetically altered corn made for livestock. The proponents of engineered foods believe it is safe, but many scientists, environmental activists, and some farmers think more studies should be done. The risks are said to be allergic reactions. "Genetic modification frequently use proteins from organisms that have never before been an integral part of the human food chain". Antibiotic resistance can also occur because of the alteration. And  the threat of cross pollination. Genetically modified crops are often dominant and there is a concern of pharmaceutically altered crop contaminating non-gentically modified crop as in Texas when a vaccine for pigs with a stomach disease was mixed. In some studies the use of modified crops required more pesticide and herbicide use that traditional crops. In effect some crops because of their genetic characteristics become more like weeds. The reduction of biodiversity, greater use of pesticides and herbicides is a concern among environmentalist. In years we've see the reduction of small scale farming. If the crops require harsher pesticides due to their resistance this can impact our ecosystem. In some tests the "pest resistant crops failed to deliver". Because genetically modified crops share different evolutionary paths when introduced into an environment it can contaminate the existing plants.  Growing modified crops require that the seeds be purchased from the biotech company that supplies them and often times the cost is greater than conventional seeds with the hope of a greater yield. The proponents against genetically modified crops seem to say  that the dangers outweigh any of the benefits

I think it is a difficult issue, and the topic is broader than it suggests. I tend to agree that there are too  many ways for contamination to occur. The long term effects are not yet known. I do agree that it's worth looking into more because it deals with areas of health on an individual and global scale and the sustainability of food supply and the food chain is also linked to our ecology. I can see the concern, alterations on a cellular level comprises many variables.  

Reference:

http://www.bio-intergrity.org/health-risks/health-risks-ge-foods.htm

http://online.sfsu.edu/~rone/GEessays/WhatisGE.html

Dragon-Punnett Square Lab

Meiosis division results in  daughter cells that are not identical and the resulting offspring can manifest different phenotype. Meiosis creates genetic diversity. During fertilization depending on  cell makeup the offspring can vary from the parent because of a recessive gene. In the diagram of the dragons genetic makeup the letters can match up but if there is a recessive trait it will show up in the phenotype although the genotype is similar. How the alleles interact affects the appearance of the offspring. The alleles constitute the genotype and the genotype expresses the phenotype.  

The Punnett square was developed by R C Punnett an English Biologist. It is used to help determine ways that alleles combine. A cell carries two alleles for each trait. One from the mother  and another from the father. Each has two alleles for each trait. A homozygote has two identical alleles and a hetrozygote has two different alleles for a gene.  A dominant allele is shown as uppercase letters and the recessive in lowercase letters. Homozygous dominant is a genotype that is shown in the square as LL, homozygous receptive is ll, and hetrozygous is Ll. Dihybrid cross is when two traits are being considered and monohybrid is when one is being considered.

http;//genome.gsc.riken.go.jp/hgmis/posters/chromosomes/faqs.html

Genetics Compendium

Early Fetal Development

Fertilization-occurs when a sperm makes it's way through the corona radiata where the acrosomal membrane digests through the zona pellucida and binds to and fuses with the egg's plasma membrane. When the sperm enters the egg, and the sperm nucleus joins with the egg nucleus to form a zygote.

Processes required for development are cleavage when the zygote divides by mitiotic divisions. Each cell has the full amount of chromosones (23 pairs). The mass of cells now called a morula increases in size and the inner cell mass becomes present to become a blastocyst. Identical twins are formed when if the morula splits. Fraternal twins are formed by two separate eggs and sperm.The blastocyst implants in the uterus and is then called an embryo. Embryo experiences growth, increase in size; morphogenisis where the embryo assumes different shapes; and differentiation when the cells start to specialize in function and structure.

Extraembyonic membranes- are outside the embryo and consist of the chorion, the fetal half of the future placenta that gets nourishment from mom, and rids waste from fetus. The allantois develops into placenta arteries, veins, and bladder.The umbilical arteries and veins exchange blood. The yolk sac is where blood cell formation and blood vessels form. And the amnion is the fluid that cushions and protects the fetus from temperature extremes and shock.

Gestation period-is 280 days normally, from start of last menstrual period to the expected date of delivery. It's in the first week of gestation that the blastocyst implants into the uterus, clinically known as pregnancy.

Embryonic development-

2nd week of gestation, HCG is secreted by the chorion and affects the corpus luteum which secretes hormones that ends the menstrual cycle and is also the hormone to determine pregnancy. The inner cell mass becomes an embryonic disc in a process called gastrulation. The yolk sac forms the first sight of blood vessel formation, the amniotic cavity fills with amniotic fluid and the cells of the inner mass differentiate into 3 primary germ layers: ectoderm, mesoderm, and endoderm. 

3rd week, nervous system and circulatory system start to develop including the heart

4th and 5th week, the body stalk becomes the future umbilical cord that connects the embryo to the chorion, the future placenta. The allantois becomes the umbilical artery and veins. At this time limb buds appear, the head enlarges: and the eyes, ears, and nose appear.

6th-8th week,embryo starts to resemble a human, reflexes develop.

Fetal developement- After 2 months the embryo becomes a fetus.

3rd-4th month, the head becomes larger in proportion to the rest of the body, and the fingernails, nipples, eyelashes, eyebrows, and hair on the head appear. Cartilage begins to be replaced by bone. Fetal sex can be seen on ultrasound and the heartbeat can be heard with a stethoscope on mom's abdomen.

5th-7th month, movement can be felt, eyelids open. The baby can survive if it is born at the end of this period.

8th-9th month, full term babies have the best chance to survive and premature babies can suffer from respiratory distress syndrome, jaundice, and infections.

Genes/Chromosones in Inheritance

Every cell has 46 chromosomes. a chromosome has two sister chromatids held together by a centromere. Chromosomes  are paired, males have XY and females have XX. 

The Cell Cycle- consists of interphase, 90percent of the cycle and cell division. There are 3 stages in interphase: G1stage the cell doubles, S stage it replicates. and G2 the cell breaks down proteins for cell division.  There are 2 types of cell division, Mitosis and meiosis, and 2 stages mitotic and cytokinesis.

Mitosis-when the parent cell divides into two daughter cells that are identical to the parent cell through the process of prophase, metaphase, anaphase, and telophase. 

Meiosis-when cell divides into four daughter cells that are not identical. Spermatogenisis and oogenisis involve meiosis.

Chromosome inheritance-A chromosome carries genetic information in a certain order. When nondisjunction occurs it results in  trisomy, 24 chromosomes or monosomy 22 chromosomes. Nondisjunction can result in too many or too few sex chromosomes. Example is Turner Syndrome were only one chromosome is apparent. Certain syndromes can be traced to chromosome structure changes. The kinds of changes include<>

DNA/genes in cell metabolism

DNA is a found in the nucleus of the cell and stores gene information, can replicate, and undergo mutation. It has a double helix and is comprised of a series of nucleotides. The phosphate and sugar molecules are the backbone of the paired bases. Replication occurs creating two identical molecules. RNA are made up of sugar ribose and assists DNA in protein synthesis. Three types of RNA assist in the process: rRNA found in ribosomes, mRNA which act as messengers, and tRNA which tranfers amino acids to ribosomes. Protein synthesis requires transcription when a copy is made and translation that occurs when a codons from MRNA match up to a sequence of amino acids.

Cellular basis for cancer

Cancer develops in various stages and is a cellular disease. The cells replicate divide unlimited times. Cacinogenisis  starts with initiation when the cell starts to divide, promotion when the tumor develops, and progression when the cells mutate and starts to invade other cells.

Recombinant DNA- Genetically modified form of DNA created by the insertion of DNA into an "existing organismal genome.  A restriction enzyme is used to fuse a human DNA with a plasmid DNA. Another enzyme DNA ligase seals the opening and the rDNA molecule is ready. Bacteria take up the plasmid.  when plasmid replicate it becomes a clone. The resulting bacteria can also result  in becoming a product.

Cell Compendium

Cells

Basic Characteristics of Life-

  Share common structure of organization 

  Take materials and energy from the environment

  Reproduce

  Growth and Development

  Interact with environment through stimuli

  Evolve

Molecules of Life 

Pairing of two or more atoms creates a molecule. When different atoms combine it creates a compound. There are 4 types of organic molecules: 

1. Proteins- Composed of amino acids they support structure and functioning of cells. It is within the skin hair and nails such as keratin and collagen. In enzymes they create specific chemical reactions. When in the plasma membrane they help to transport materials in and out of the cell. Hormones and antibodies also consist of proteins. Certain proteins also help in muscle contraction.

2. Carbohydrates- Are sugars that function in the storage and transport of short - term energy.They have a 2:1 ratio of hydrogen to oxygen similar to water. They are the main energy source for the human body. The process of metabolism releases energy. There are 2 types: Simple carbohyrates are called monosaccharides. Examples are fructose,

glucose, galactose. "When humans eat starch, glucose is absorbed into the bloodstream. Once absorbed, the human body distributes glucose to the areas where it is needed for energy".Complex carbohydrates are polysaccharrides consisting of long chain simple sugars. 

3. Lipids - Functions in storing of energy, signaling pathways, insulating the body, and forming of cell membrane. A high energy source not water soluble. It includes cholesterol, sterol, glycerides and fatty acids which are neutral and don't carry a charge. Phosholipids are different in molecular structure, having phosphate and nitrogen. They are polar and form the cell membranes. Steroids differ by having 4 fused carbon rings. Testosterone, estrogen, and cortisol are important to reproduction and metabolism.      

4. Nucleic Acid - There are 2 types DNA and RNA. DNA stores genetic info and is like a blueprint that contains instructions for the components of cells, proteins, and RNA molecules. The part of The DNA that carries the instruction is the genes. DNA is able to replicate and transmit the information when a cell reproduces. RNA is involved in protein synthesis. Both are polymers and macromolecules which are made of sugar, a base, and phosphate. Sugar deoxyribose is DNA and RNA contains the sugar ribose. DNA has a helix  and is double stranded and RNA is single stranded without a helix. ATP is a high energy molecule created when adenine and ribose are changed by a regrouping of three phosphates.

Cell Structure and Function

Cells form the structure of living organisms. The cell is the smallest unit of life capable of exhibiting the basic characteristics of life.

The Cell Theory states that all cells come from other cells, all of life is made of cells, and that cells are the basic unit of life. Cells can be different in shape and function. 

The outer shell of the cell is called the plasma membrane it is permeable and regulates what enters and exits the cell. The membrane contains proteins and lipids.Diffusion is a process of molecules equally distributing from high to low areas of concentration. It creates a means for molecules to enter and exit a cell. Osmosis moves water  and a solute across the membrane. Facilitated transport is when a protein is used as a carrier to cross the membrane. Diffusion, osmosis, and facilitated transport are "passive" they don't require energy to facilitate movement. Active transport requires cellular energy, a protein carrier and moves from low to high. Endocytosis is a process that takes in substances through the membrane by creating a "pouch" and exocytosis is the process when a "pouch" is formed to release a substance. Within the membrane is a fluid consisting largely of protein called the cytoplasm where various organelles reside. 

Cell Organelles and Metabolism

Membraned bodies within the cytoplasm with specific design and functions.

1.Endoplasmic reticulum- channels that connect the nucleus to the cell membrane. There are 2 types, rough and smooth. Rough contains ribosomes and smooth do not.

2.Ribosomes- are attached to the endoplasmic reticulum and where RNA synthesize proteins.

3.Gogli apparatus- flat stacked membranes where sugars are converted to starch or bonded to proteins and lipids.

4.Vesicle-a storage sac that can move between organelles by endocytosis or exocytosis.

5.Lysomes- are found in all cells, contain enzymes that break down macromolecules.

6.Mitochondria- where cellular metabolism occur. Converts glucose into ATP molecules in the process of cellular respiration. Cellular respiration is an important metabolic process that releases energy slowly. The process of converting glucose is called glycolysis. 

7.Nucleus-contains DNA information and contained in a double membrane. 

Cytoskeleton- its protein meshing maintains the cells shape and buffers organelles. There are 3 different tubules: microtubules,actin filaments, and intermediate filaments. The centrosome organize center of the microtubes. The cilia and flagella are have micotubes in the center. Their protein projections create movement.   

Tissue Types

Tissue comprises of cells that are specific to its function. There are 4 types:

Connective Tissue 

Fibrous connective tissue are made of fibroblasts that support the internal organs.

Adipose is another connective tissue that stores fat, protects, and insulates. 

Dense fibrous connective tissues is in tendins, ligaments and connect muscle to bone. 

Supportive connective tissue consisting of cartilage is called hyaline cartilage, elastic cartilage is found in the ear, and fibrocartilage is found in knee joints and vertebrae.

Fluid connective tissue include blood:white blood cells and platelets, and lymph that absorb fluids.   

Muscular Tissue

Contain actin and myosin proteins that enable movement.There are 3 types: skeletal muscle which are striated and voluntary with multiple nuclei, smooth muscle can be found along the walls of organs and is involuntary and has a single nuclei, and cardiac muscle which lines the heart is striated and involuntary. 

Nervous Tissue 

Form a communication network consisting of neurons and neuroglia. Neurons are made of dendrites which receive signals, the cell body, and axon which conducts impulses,

Epithelial Tissue

Forms along the body cavities consisting of tightly packed cells. It is exposed on one side and secured to connective tissue on the other.There are 5 types:

Simple Epithelia

Squamous epithelium has a single layer of cells, found in the lining of the lungs and blood vessels. Cuboidal epithelium also has a single layer and is found in the glands. Columnar epithilium line the digestive tract and oviducts and are columnar in structure. 

Pseudostratified Columnar Epithelium line the windpipe and.

Transitional Epithelium can be found lining the urinary bladder and urethra and can change according to tension.

Stratified Epithelium have layer of cells and can be found in the nose moth esophagus and cervix.

Glandular Epithelium secretes a substance to be move to the blood or ducts.

cellBy Fujoshi on Flickr

www.flickr.com

Conclusion: the making of the model was challenging and provided a better understanding of the parts that work together and why. The most difficult part was figuring how where the pieces should go.

Illustrates DNA transciption, tRNA translation and the role of proteins (amino acid chain).

These are the phases of Mitosis which produce two identical daughter cells.

Double stranded DNA and it's base pairs

This model shows the multiple chromosomes in the nucleus.

Lab-Cell Model

These are the materials used to build my cell model.










Here are the parts of the cell:
cell membrane-the boundary of the cell that contains proteins and lipids
nucleus and nuclear membrane-where the genetic information is stored and the outer sac
endoplasmic reticulm-tubules and sacs where proteins and lipids are synthesized
rough w/ribosomes-where proteins are synthesized
smooth w/ribosomes-where lipids are synthesized
gogli apparatus-flat stacks where sugars convert to starches and or bonded to proteins or lipids
lysomes and vesicle-contains enzymes for digesting macromolecules
mitochondria-facilitates cellular metabolism
Cilia and flagella-projections from cells that create movement

Onion Tip 40x

The Microscope

The micoscope consists of:

Stage: The platform where the specimen is placed

Focus Knob:  Focusing is adjusted by turning the coarse and fine knobs to bring in or sharpen your image

Iris: It controls the amount of light that comes through the slide 

Oculars: These are the lenses that you look through to view your specimen

Objectives: They are the lenses that provide magnification. They rotate on the nosepiece.

Brief History of microscope

.The first microscope was made around 1595. Zacharaias Janssen produced the first compound microscope . The making of the compound microscope advanced the field of Microbiology.It had the magnification of 3x to 9x. Robert Hooke an English Inventor, improved the compound micoscope around 1660 and was credited with "coining the word cork" that he discovered through the microscope. He was also a mathematician and formulated the theory of planetary movement. Anton Van Leeuwenhoek  built simple microscopes and is known as the first person to describe bacteria. He was insipred by the readings of Robert Hooke. In 1873 Ernst Leitz introduced objectives that rotated on a nosepiece. And in 1931 Max Knoll and Ernst Ruska introduced the first electron microscope. 

Microscope User's Guide

 

   Mechanical Adjustments

  

   1.  Turn the condenser knob all the way up

   2.  Turn the fine focus knob to mid range

   3.  Adjust left and right oculars to 64 

   4.  Move blue filter into place

   5.  Rotate the 4x objective into place

   6.  Turn on microscope

   7.  Turn rheostat dial to 10 

   8.  Place specimen on stage and secure stage clips

   9.  Use XY controls to adjust specimen so light is passing through it               (opening the iris provides more light 

       and makes it easier to line-up the specimen)

  10.  * REMEMBER* to close the iris, always do this before looking                     through the oculars.

  11. Raise the stage as high as it can go by turning the coarse focus knob        clockwise

   

    Viewing Adjustments 

    

   12.  Adjust the oculars  in and out until you see one image 

   13.  Looking through the microscope slowly adjust the coarse focus                 until image comes into view

   14.  Use fine focus to create a sharper image

   15.  Now you can center your specimen by using the XY controls again

   16. To view specimen under other objectives 10x, 40x, etc., rotate                objective into place and repeat steps: 13,14,15 * As

          magnification increases, opening the iris slightly might be helpful.