Chapter 4

Types of Tissue

There are four types of tissue in the human body connective, muscle, nervous, and epithelial tissue.

Connective Tissue

Of the connective tissue there are four types, loose fibrous, dense fibrous, cartilage and bone, and blood. An example of loose connective tissue is areolar tissue that supports the epithelium and organs. Dense connective tissue can be found in ligaments and tendons that connect bone to bone or muscle to bone. Next is cartilage and bone. Cartilage is found in the nose, knee, in between vertebrae, and also the ears as well as other places. Bone, well there are compact and spongy. Compact bone makes up the shaft of long bones made up of cylindrical structures called osteons. While spongy bone structure appears more open, and irregular is for support strength.

Fluid Connective Tissues

Blood has multiple formed elements in it. Red blood cells, which is the carrier of oxygen. White blood cells fight disease and infection by either engulfing the pathogen or producing antibodies. Lymph is fluid derived from tissue fluid that is then carried to lymph nodes for further processing.

Muscular Tissue

Muscle fibers are made up from actin and myosin filaments, which are types of protein filaments. There are types of muscles, skeletal, smooth and cardiac. Skeletal muscles are just as the name implies, they work with the skeleton to allow voluntary locomotion. They have a striated cell structure with multiple nuclei. Smooth muscle is found in the walls of blood vessels and internal organs and are not under voluntary control like skeletal muscles. They have no striations and are spindle shaped cells with a single nucleus. Cardiac muscle is the third type, and is only found in the walls of heart. And have a combination of striated cells with a single nucleus per cell.

http://cal.vet.upenn.edu/histo/muscle/muscle.html

Nervous Tissue

Nerve tissue is comprised of nerve cells called neurons, and neuroglia (which are the cells that nourish and support the neurons). Neurons consist of dendrites (which receives impulses from sensory receptors or other neurons), a cell body (which contains the nucleus and cytoplasm), and an axon (which is an extension that conducts impulses). The neuroglia out number neurons nine to one in the brain and can communicate with each other as well as with the neurons. There are different cell types of neuroglia; microglia will engulf cellular debris and bacteria. Astrocytes provide nutrients and hormones. Oligodendrocytes form a type of sheath made of myelin to surround fibers in the brain and spinal cord.

http://www.valleyhealth.com/images/image_popup/r7_neuron.jpg

Epithelia Tissue

Simply put epithelia tissue protects by forming a layer of tightly packed cells to form a continuous layer. Examples of this are the skin, the lining of and the covering of body cavities.

There are five distinct types of epithelia, simple, pseudostratified columnar, transitional, stratified, and glandular. Each has a different role to either carry out secretions, absorption, excretion, and filtration. Simple has three types, squamous epithelium is found in the lining of blood vessels and the lining of the lungs used as protection. The second type or cuboidal epithelium is found in the lining of kidneys and various glands to absorb molecules. The third type of simple epithelium is columnar which is found in the lining of the small intestine and oviducts to absorb nutrients. Pseudostratified columnar epithelium is found in the lining of the trachea and is lined with cilia is coated with mucus that sweeps foreign debris away from the lungs. Stratified squamous is found in the nose, mouth, esophagus, anal canal, and vagina for protection. And lastly, glandular epithelium such as sweat glands, mammary glands, and glands in the pancreas.

http://cal.vet.upenn.edu/histo/epithelium/epithelium.html

Cell Junctions

There are three types of cell junctions between epithelia cells. Gap junctions that allow molecules and signals to pass between cells. There are adhesion junctions that allow cells to bend and stretch. And there are also tight zipper like connections between cells.

Integumentary System

Organs that contain two or more accessory organs is called an Integumentary System. The skin is such a system with the accessory organs hair, sweat glands, sebaceous glands, nails, and oil glands. The regions of the skin consist of the epidermis layer, where stem cells create new epithelial cells, and the dermis layer, which contains all of the accessory organs as well as nerve endings, blood vessels, and sensory receptors. The skin helps our whole body to maintain homeostasis by protecting underlying tissue and helping regulate body temperature.

Cardiovascular System

Which contains the heart and blood vessels, transports blood, nutrients, gases, and wastes; while maintaining pH and fluid balances. Helps control temperature by distributing heat and also helps defend against pathogens.

http://www.besthealth.com/besthealth/bodyguide/reftext/images/8747.jpg

Lymphatic and Immune Systems

Contains lymphatic vessels, lymph nodes, spleen and other lymphatic organs. It helps control body fluid levels with the cardiovascular system. Helps in the storage of lymphocytes and white blood cells that produce antibodies.

Digestive System

The simplest way to explain such a complicated system is the ingestion/digestion of food, absorption of nutrients, and the elimination of waste byproducts.

http://www.zoomschool.com/subjects/anatomy/digestive/color.GIF

Respiratory System

Is the system where gases are exchanged and pH balance of the blood is maintained through the exchange of gases.

http://images.google.com/imgres?imgurl=http://t3.pacific.edu/teams/M007305/respiratorydetail.gif&imgrefurl=http://t3.pacific.edu/teams/M007305/respiratorysystem.html&h=430&w=425&sz=64&tbnid=9DnclDmJRONWxM:&tbnh=126&tbnw=125&prev=/images%3Fq%3Drespiratory%2Bsystem%26um%3D1&start=1&sa=X&oi=images&ct=image&cd=1

Urinary System

Contains the kidneys, bladder, and the tubes that carry urine, a waste product. The system helps maintain the pH and salt/water balances in the blood.

Skeletal System

Helps support the body, helps the body move, provides protection for the body, stores minerals, and produces red blood cells in the bone marrow.

http://www.contmediausa.com/shop/app/products/Human3D/Images/BS000A.jpg

Muscular System

Works in conjunction with the skeletal system to help the body move and maintain posture. Muscle contraction creates heat for the body. And smooth muscle helps organs work. While cardiac muscle pumps blood.

Nervous System

Basically consists of the brain, spinal cord, and all nerves. This allows us to respond in a variety of ways to external and internal stimulus. This is also how the brain communicates with the rest of the body to regulate body functions.

Endocrine System

The nervous and endocrine systems work together to regulate the rest of the bodies systems. The endocrine system does this chemically through the blood stream by releasing hormones.

http://scienceblogs.com/clock/2006/06/bio101_lecture_6_physiology_re.php

Reproductive System

Differ from male to female in humans but basically male and female produce and supply gametes, and produce gender specific hormones. The female also carries, gives birth, and nurtures the offspring.

Homeostasis

Homeostasis is maintained when all of the human body systems are working together in concert with each other.

Negative and Positive Feedback

Negative and positive feedbacks are the processes in which the body uses internal and external stimuli to maintain the body.

Sources:

Human Biology 10^th Edition by Sylvia S. Mader

http://cal.vet.upenn.edu/histo/muscle/muscle.html

http://www.valleyhealth.com/images/image_popup/r7_neuron.jpg

http://cal.vet.upenn.edu/histo/epithelium/epithelium.html

http://www.besthealth.com/besthealth/bodyguide/reftext/images/8747.jpg

http://www.zoomschool.com/subjects/anatomy/digestive/color.GIF

http://images.google.com/imgres?imgurl=http://t3.pacific.edu/teams/M007305/respiratorydetail.gif&imgrefurl=http://t3.pacific.edu/teams/M007305/respiratorysystem.html&h=430&w=425&sz=64&tbnid=9DnclDmJRONWxM:&tbnh=126&tbnw=125&prev=/images%3Fq%3Drespiratory%2Bsystem%26um%3D1&start=1&sa=X&oi=images&ct=image&cd=1

http://www.contmediausa.com/shop/app/products/Human3D/Images/BS000A.jpg

http://scienceblogs.com/clock/2006/06/bio101_lecture_6_physiology_re.php

Unit I Ethical Paper

GMO’s: Environmental Boon or Bane?

Genetically modified food is on our grocery shelves and more and more acreage every year all over the world is dedicated to crops grown with genetically modified seeds. There is a huge controversy regarding the environmental and health issues involved with these foodstuffs. There are scientists who weigh in on both sides of the issue as well as ones that present the facts as they currently are using available studies and data without taking a side one way or the other. There are other more ideological and political issues involved in the controversy, such as lack of clear labeling laws, control of the patents on seeds by a few large corporations, world hunger, and food distribution issues that I won’t address here in the interests of brevity.

Anti-GMO organizations and activists have several main criticisms of GM food. One: that cross-pollination, or ‘outcrossing’ of conventionally grown crops – particularly organically grown crops – from the pollen of modified plants is problematic and can’t be controlled because it happens when the wind blows or is carried by insects from plant to plant. There is an article in a current Fortune magazine talking about a strain of genetically modified rice that everyone in the US had agreed they didn’t want to grow because their customers in Europe and Asia wouldn’t buy it. Crops that had been planted were destroyed. Yet recent tests done on several crops have shown that the genetic marker of that GM rice is showing up in crops that weren’t planted with those seeds, giving credence to the concerns that once put into fields, there is no controlling where these organisms can and will end up. Industry sources don’t give credence to this concern. The stance seems to be that it is natural for pollens to travel and that it will only enhance other crops genetic structures and shouldn’t be a concern.

Two: that despite claims of decreasing pesticide use on varieties bred for pest-resistance, more herbicides are actually being used than before. While the GM industry doesn’t necessarily deny that the use of broad spectrum herbicides has increased, they do refute that these herbicides are highly toxic to humans, citing a study by the Environmental Defense Fund saying that they are among the least hazardous of the chemicals in their database. They also say that if using these GM crops causes broader use of herbicides, but reduces the only claimed alternative of excessive cultivation, which isn’t sustainable because of soil erosion, then ultimately it’s more environmentally friendly.

Three: insects and weeds could ultimately mutate and become resistant to the introduced genes put there to resist them in the first place. Problems with some Canadian growers that have found herbicide tolerant volunteer plants are cited as an example of this concern. The GM industry says this claim is false and that in fact biotech crops have always worked to make sure this type of resistance can’t happen and say that the resistant plants that have been observed were from conventional crops, not bioengineered ones.

This is just three of at least a dozen or more points and counter-points that can be found in researching GMO’s. The list also contains concerns that GMO’s aren’t safe, that they can’t solve world hunger, that they are making their way into our ‘human gut’ creating the possibility of causing potential health problems. The industry refutes, cites scientific studies, or just says the claims are false in each case. It is difficult to make an intelligent decision about whether genetically modified food is indeed a danger. In the final analysis, in the absence of actual proof that they’re NOT dangerous in a multiplicity of ways, it would only seem prudent to be extremely careful about the continued propagation of these types of crops. It would seem, however, that the genie is out of the bottle. If even half of what the anti-GMO groups say proves to be accurate, we’ve already contaminated our environment and it will be difficult to dial it back. The ‘mutant rice’ article in Fortune is ample enough evidence of that.

Genetics Lab

In the first picture I had to change around the genotype to phenotype to match the second dragon to the first. The second dragon actually started out with 4 legs, red body, and no horns.

In the second picture we see the flies that I had to cross two heterozygous flies with a dominant long winged trait to get offspring with a 1:2:1 ratio. One offspring will be homozygous dominant with long winged traits, that is two alleles for long wings. Two will be heterozygous with one allele for long wings and another with short wings. The last offspring will be homozygous recessive with two alleles for short wings and will in fact physically have short wings, even though the parents and all other siblings have long wings. An easy tool to use for genetic traits is a Punnett square.

Genetic inheritance is a very important part of why we are the way we are, look the way we look, and even what makes us alike to our parents and siblings. Genes have played a major role in how we have evolved to be what we are today. The theory that we all came from a similar background and have evolved to walk upright, have an opposable thumb, have developed speech and thought patterns, and have a bigger brain are all traits that have been passed down to us over thousands of years. Our great ancestors slowly developed these traits over many generations, and have passed them down to us. There are many types of characteristics and even diseases that we can inherit from our parents such as; attached or unattached earlobes, wavy or straight hair, and short or long fingers. Diseases occur when there is an abnormality in one of the chromosomes of our genetics. Diseases include Tay-Sachs disease, Cystic Fibrosis, and Downs Syndrome. There are inheritances that we get from our sex-linked chromosomes as well such as color blindness. If a father has homozygous alleles for color blindness, and the mother is a carrier then we know that all of the sons will be colorblind. Muscular Dystrophy is also a sex linked inheritance. It is important to have a basic understanding of what these terms mean. A genotype is a trait or characteristic that is written into the genes of the DNA of a living object. An allele is a different form of a gene that shares a same position on a chromosome. Alleles always come in pairs. A phenotype is the actual characteristic that the offspring will have. In the fruit fly lab, the genotypes were for short or long wings. The alleles were either dominant or recessive. Dominant being the trait that is “stronger” or more likely to occur and is always assigned a capital letter. In the fruit fly lab, long wings is the dominant allele and therefore given a capital L. Short wings are a recessive trait and given a lower case l. A recessive trait is one that is still prevalent, but must be paired up with another recessive trait to become a phenotype. An easy way to remember the difference between genotype and phenotype is to remember that a genotype starts with ge and therefore is the genes. Phenotype starts with ph and is the physical traits. A cross is the result that you get from breeding two parent subjects and getting the offspring. The dominant or recessive traits will show up depending on if the parents are homozygous dominant, heterozygous, or homozygous recessive. A homozygous dominant parent will have both dominant alleles, noted by two capital letters such as LL. A heterozygous parent will have both a dominant and a recessive trait noted by a capital and lower case letter Ll. A homozygous recessive will have two recessive traits and is noted by two lower case letters ll. In conclusion, this was a very educational lab that showed a simple and fun way to cross different parents and get offspring, or in the dragon lab, manipulate the genotypes of the dragon to make him just like the other one. We have seen how the different genotypes with their dominant or recessive alleles can change the phenotype of the offspring. I think a good thing to remember is that just because there is a three to one ratio doesn’t mean that if you have four offspring, one will not necessarily be different from the other. They might all be the same or have a half and have mix.

Unit I The Cell Lab

Here is my crude representation of a cell and its major components. With the chromosomes and how a DNA strand replicates and the amino acids it forms in the process to replicate additional DNA strands for cell division.

Ribosomes made out of Playdoh.

Golgi apparatus made out of gummi worms.

Mitochondria made out of candy orange slices.

The nucleus with ribosomes made out of sticky Styrofoam balls.

Vesicles made out of jelly beans.

Lysosomes made out junior mints.

Flagella made out of ribbon.

Chromosomes made out of pipe cleaners.

A close up of the cell with a plastic bag as the lipid membrane, angel hair pasta as the microtubules, Karo syrup as cytoplasm, and red string licorice as endoplasmic reticulum

A better view of the cell with a plastic bag as the lipid membrane, angel hair pasta as the microtubules, Karo syrup as cytoplasm, red string licorice as endoplasmic reticulum and the flagella present.

The next pictures shows mitosis of a cell.

Both cells are in interphase. C = chromatin, I = nucleolus.

Interphase is the "holding" stage or the stage between two successive cell divisions. Some 90 percent of a cell's time in the normal cellular cycle may be spent in interphase. While the name might sound passive, there are a number of processes that occur in interphase. If viewed under a microscope, the cell may appear to be dormant. In actuality however, biochemical activity is high during interphase.

The arrow is pointing to the dark region, which is condensing chromatin.

Prophase is a beautiful menagerie of changes that occur in both the cytoplasm and nucleus of the dividing cell. Many consider prophase (versus interphase) to be the first true step of the mitotic process. In prophase, the chromatin condenses into discrete chromosomes. The nuclear envelope breaks down and spindles form at opposite "poles" of the cell.

Ch = chromosome, S = spindle

In metaphase, the nuclear membrane disappears completely. The spindle fully develops and the chromosomes align at the metaphase plate (a plane that is equally distant from the two spindle poles).

Cell in mid anaphase.

In anaphase, the paired chromosomes (sister chromatids) separate. Spindle fibers attached to the sister chromatids shorten and begin moving them to opposite ends (poles) of the cell. Spindle fibers not connected to chromatids lengthen and elongate the cell. At the end of anaphase, each pole contains a complete compilation of chromosomes.

Cell in early telophase. The arrow points to the formation of a cell plate.

In early telophase, nuclei begin to form at opposite poles. Cytokinesis, the division of the original cell's cytoplasm, also begins. In plants, the cell begins to form a cell wall.

This cell is in late telophase. The arrow is pointing to the cell plate, which divides the cell into two new cells.

In telophase, the chromosomes are cordoned off in distinct new nuclei in the emerging daughter cells. The division of the original cell's cytoplasm is called cytokinesis. It begins prior to the end of mitosis and completes shortly after telophase/mitosis. At the end of cytokinesis, there will be two distinct daughter cells.

This shows the DNA replication sequence

These are the amino acids formed after replication.

AMINO ACID

RNA CODON

ALANINE

GCC, GCA, GCG, GCU

ARGININE

AGA, AGG, CGU, CGA, CGC, CGG

ASPARAGINE

AAC, AAU

ASPARTIC ACID

GAC, GAU

CYSTEINE

UGC, UGU

GLUTAMIC ACID

GAA, GAG

GLUTAMINE

CAA, CAG

GLYCINE

GGA, GGC, GGG, GGU

HISTIDINE

CAC, CAU

ISOLEUCINE

AUA, AUC, AUU

LEUCINE

UUA, UUG, CUA, CUC, CUG, CUU

LYCINE

AAA, AAG

METHIONINE (INITIATION)

AUG

PHENYLALANINE

UUC, UUU

PROLINE

CCA, CCC, CCG, CCU

SERINE

UCA, UCC, UCG, UCU, AGC, AGU

THREONINE

ACA, ACC, ACG, ACU

TRYPTOPHAN

UGG

TYROSINE

UAC, UAU

VALINE

GUA, GUC, GUG, GUU

STOP

UAA, UAG, UGA

Sources:

Human Biology tenth edition, Sylvia S. Mader

http://biology.about.com/od/mitosis/ig/Mitosis-Image-Gallery/index.htm

http://www.ncc.gmu.edu/dna/genetic.htm

http://www.ncc.gmu.edu/dna/makemRNA.htm

http://www.ncc.gmu.edu/dna/nucleic.htm

In conclusion it takes an awful lot of time to display what happens in such a short time and in every cell we have but this is truly life. This lab was a lot of fun although increadable time consuming.

I feel as though I should geta B out of this lab after meeting the criterea below:

• Introduction presents model clearly
• List of cell parts explains how they are represented in the model. There is an understandable and consistent relationship between the model parts and what they are in the cell
• Model includes representation of all the basic parts of a cell listed above. It is easy to understand why each model piece was chosen to represent a certain part of the cell.
• Chromosomes, DNA, mRNA and proteins are represented. Pieces are used that make it easy to see how these molecules function in the cell.
• Description of DNA replication and transcription/translation are presented. They are shown in their entirety and it is easy to follow how each process happens.