Friday, January 20, 2012

Major Plant Division

Bryophytes:
The three phyla of bryophytes are mosses, liverworts, and hornworts. In the life cycles of bryophytes, the gametophyte is the dominant generation. Their gametophytes are generally only one or a few cells thick and because of this, it places all cells close to water and dissolved minerals. Most bryophytes lack conducting tissues that can distribute water and organic compounds within thick tissues. Some bryophytes have specialized tissues that function in water and solute condition. They have cell walls that lack the lignin coating on the outside and because of this their structure is not as great. The absence of lignin limits the height of bryophytes.

Pteridophytes:
They are seedless vascular plants. Lycophyta and Peterophyta are the two phyla of modern seedless vascular plants. Most pteridophytes have true roots with lignified vascular tissue. Plants that are in the pteridophytes category include horsetails and ferns. The sperm of ferns and all other seedless vascular plants are flagellated and must swim through a film of water to reach eggs. Because of this, seedless vascular plants are most common in damp areas.

Gymnosperms:
Gymnosperms lack the ovaries in which angiosperm ovules and seeds develop. Instead, Gymnosperm ovules and seeds develop on the scales of cones. The Mesozoic era was the age of gymnosperms. These four phylas are grouped as gymnosperms, gingko, cycads, gnetophytes, and conifers. The most familiar group of gymnosperms is the conifers because of the cones that they have.

Angiosperms:
They are better known as flowering plants. They are also vascular seed plants that produce the reproductive structures called flowers and fruits. All angiosperms are placed in a single phylum, this phylum is called phylum Anthophyta. The flower is an angiosperm structure specialized for reproduction. Sepals, petals, stamens, and carpels are the structures that basically make up the flower. Insects and animals transfer pollen from one flower to a another flower's female sex organ. This life cycle of angiosperms proves to be a highly refined version of the alternations of generations which is shared between most plants.

SOURCES: CAMPBELL BIOLOGY BOOK AND IMAGES FROM GOOGLE.

Exemplars of Phyla of Protozoas

Phylum Rhizopoda (Amoebas)
Entamoeba histolytica-
Are unicellular and use pseudopodia to move and to feed. The pseudopodia may bulge anywhere on the cell's surface. When an amoeba moves, it extends a pseudopodia and anchors it's tip and then more cytoplasm will stream into the pseudopodium. Their cytoskeleton conssts of microtububles and microfilaments. Some amoebas live inside a protein shell that they secrete. Amoebas are found in freshwater and marine environments are are also found in soils. They spread by contaiminated drinking water, food, or utensils.


Mycetozoa:
Dictyostelids-
-Used as examples of cellular communication and differentiation. They also provide insights into how multicellular organisms develop. Mycetozoa basically translates to fungus animals. Slime molds have structures that maximize exposure to their food sources and they also have complex life cycles that contribute to survival in changing habitats. Plasmodial slime molds are brightly yellow or orange pigment. The plasmodium engulfs food particles by phagocytosis.

Euglenozoa:
Kinetoplastics-
They are symbiotic and are pathogenic to some of their hosts. For example one of their species Trypanosoma cause African sleeping sickness, through the bite of a tsetse fly. They are characterized by an anterior pocket where the flagella emerges. They sometimes have two flagella. The cytoskeleton of kinetoplastids is primarily made up of microtubules.

Aleolata:
Dinoflagellata-
They have small membrane-bound cavities under the cell's surface. They are the most abundant in the aquatic area where phytoplankton thrive. They provide the foundation of most marine and mant freshwater organism's food. They are heterotrophic. Most are unicellular. One dangerous dinoflagellate is called Pfiesteria pisciacida is carnivorous. When the dinoflagellate blooms it's toxin stuns finish and it feeds on the prey's body fluids.

Stramenopila:
Oomycota-
Include the water molds, white rusts, and downy milkdews. Most water molds are decomposers that grow as cottony masses on dead algae and animals, but mainly in fresh water. Some are parasitic and grow on the skin and gills of fish, but they only attack when the tissue is injured or some sort. Phytophthora infesans causes late potato blight, which is what happened during the potato famine. Watermolds and their relatives have cell walls made of cellulose. These are not really related to fungi. Some of these organisms are unicellular, and some have hyphae and are conecytic.

Chlorophyta:
Chlamydomonas-
They are the simplest of the chlorophytes and are biflagellated unicells. However, they resemble the gametes and zoospores of more complex chlorophytes. In addition to unicellular chlorophytes, there are colonial species as well as many multicellular filamentous forms that contribute to the stringy masses known to be called as pond scum. Most green algae have complex life historites with both sexual and asexual reproduction. Nearly all of them reproduce sexually by the way of biflagellated gametes.

Rhodophyta:
Also known as red algae. They lack flagella and they are usually red because they have an accessory pigment known as phycoerythrin. Red algae evolved from cyanobacteria by primary endosymbiosis. Not all of rhodophytes are red because in deep water they are almost black and at moderate depths they are bright red, in shallow water they appear to be greenish in color. They are the most abundant large algae in the warm tropical oceans. The phycobilins and other accessory pigments allow some organisms to absorb light wavelengths.

Sporozoa:
The Sporozoa are parasitic protozoans that lack locomotor organs. They have no cilia, no flagella, and no pseudopods. They are usually intracellular parasites. The Sporozoa is a very large and diverse class with at least four subclasses and many thousands of species. Malaria is one of the most important sporozoan disease. Coccidiosis, which affects poultry and cattle is another. Some sporozoans live primarily in the blood cells, while others, like live in the epithelial cells lining the intestine. They have complicated life cycles involving two hosts, which includes a sexual and asexual stage.

Parabasalids-
They lack mirochondria. The best known species is Trichomonas vaginalis, they live in the vagina of human females. They infect the vaginal lining when acidity levels of the vagina are changed. Sometimes these infections can have to males too in the urethas. They have both flagellas and an undulating membrane which helps them move within the reproductive and urinary parts of human hosts.

Ciliophora-
Most live as solitary cells in fresh water. Cilia are relatively short and are associated with a submembrane system of microtubules that can coordinate the movement of the cilia. Some ciliates are completely covered by rows of cilia, while some others have fewer rows of them.They have a unique feature, they have a presense of two types of nuclei, a large macronucleus and usually several tiny micronuclei. Ciliates generally reproduce by binary fission rather than undergoing mitotic division. They also go through conjugaton.



SOURCES: campbell biology book, images from google images, wikipedia images.
http://waynesword.palomar.edu/trnov01b.htm
http://oceanlink.info/biodiversity/seaweeds/Rhodophyta.html

Cell Poem

Cell cell cell have you any walls.
If so if so you are a plant cell.
Don't be discouraged if you dont have walls.
It's alright because you're an animal cell.

Prokaryotes and eukaryotes,
all bounded by a plasma membrane.
Eukaryote eukaryote you have a true nucleus
Yes yes prokaryotes are different
Becausee cause they hold their DNA in the nucleiod.

All goes well when ribosomes build's a cell's protein.
They take care of the metabolism changes in the body.
The same goes for the endoplasmic reticulum
One side is smooth the other side is rough
Don't be afraid remembering them is tough.
The smooth ER provides synthesis of lipids
The rough ER provides synthesis of secretory proteins.

The golgic apparatus finishes and sorts.
Ends up shipping cell products to all parts.
Lysosomes are digestve compartments.
One process known as phagocytosis.
Cell cell cell
why are you so complex
the cell membrane has glycoproteins
and a bilayer.
The cell is fluid and moves all about
This is the end of our cell poem
Don't be discouraged there's more to learn.
The cell is a complex part of the body.

Wednesday, January 18, 2012

Prion Vs. Protist Vs. Bacteria Vs. Virus

Prion:
Viroids and prions are infectious agents even simpler than viruses. A prion is a protein, they appear to cause a number of degenerative brain diseases, including scrapie in sheep, the "made cow disease" and Creutzfeldt-Jacob disease in humans. A prion is a misfolded form of a protein normally present in brain cells. When the prion gets into a cell containing the normal form of the protein, the prion converts the normal protein to the prion version. Because of this we can see that prions always calls chain reactions that increase the prion number. The hypothesis of how a prion propagate is this: when a prion contacts a normal "twin" it may induce the normal protein to assume the abnormal shape. This may continue until prions go to dangerous levels such as causing cellular malfunction and soon degeneration of the brain.


Protist:
Protists are the most diverse of all eukaryotes. Most protists are unicellular. They are found whereever there is water, living as plankton, submerged bottom swellers, or inhabitants of moist soil or the body fluids of other organisms. Protists are the most nutritionally diverse, this includes photoautotrophs, heterotrophs, and mixotrophs. Some algae which is in the protist tree have life cycles with alternating multicellular haploid and diploid generations, this means that haploid gametophytes and diploid sporophytes take turns reproducing one another. . The main groups of Protistan diversity are Diplomonadida, Parabasala, Euglenozoa, Alveolata, Stramenopila, Rhodophyta, Chlorophyta, and Mycetozoa.


Bacteria:
Bacteria have a short generation span and because of this it helps them adjust to changing environments. Since bacteria has a short generation span, new mutations can affect a population's genetic variation quickly. The way a bacteria duplicates and makes new bacteria is by transformation, transduction, and conjugation. In transformation, the DNA enters the cell from the surroundings. In transduction, the bacterial DNA is carried from one cell to the other by phages. Lastly, in conjugation, it is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells.


Virus:
A virus is a small nucleic acid genome enclosed in a protein capsid and sometimes a membranous envelope. The genome that is enclosed in the capsid may be single- or double stranded DNA as well as RNA. The only way for a virus to reproduce is within a host. Viruses use enzymes, ribosomes, and small molecules of host cells to synthesize offspring viruses. For RNA viruses, there is such thing known as retroviruses, that they do is that they use the enzyme reverse transcriptase to synthesize DNA from their RNA template. The DNA can then integrate into the host genome as a proviruses. As for plant viruses, most of them are single stranded RNA viruses. Phages, a type of viruses can undergo the lytic or lysogenic cycle in order to reproduce.




SOURCES: campbell book, biologycorner.com,

Virtual Diffusion Lab


To have the highest rate of diffusion :
Surface area: 6008.89
Volume: 4.00
Surface area/volume ratio: 1500.84
Villi: 50%
Radius: 1X
Cell shape: 10:1
Number of dimples: 20
Dimple % of cell surface area: 1

SOURCES: http://www.mhhe.com/biosci/genbio/biolink/j_explorations/ch02expl.htm

Tuesday, January 17, 2012

Cellular Metabolism Wordle

Wordle: Untitled

The chemistry of life is organized into metabolic pathways. Metabolism is a collection of chemical reactions that occur in an organism. It is aided by enzymes particularly, this is how it follows catabolic pathways or anabolic ones. The difference between the two is that catabolic means to break up while anabolic means to build. Cellular respiration and fermentation are catabolic, energy-yielding pathways. The most important part to remember in these few chapters is that respiration involves glycolysis, the krebs cycle, and the electron transport. Glycolysis and the Krebs cycle supply electrons to the transport chain. The places in which these processes occur is that glycolysis occurs in the cytosol, the krebs cycle in the mitochondrial matrix and the electron transport chain is built into the inner mitochondrial membrane. When there is no oxygen for cellular respiration to occur, fermentation enables some sells to produce ATP without the help of oxygen. One extremely important thing to remember is that ATP is basically the cell's energy shuttle. ATP drives endergonic reactions by the transfer of the phosphate to specific reactants. It comes from ADP and turns into ATP after the phosphate is added in. As for photosynthesis, the organic compounds produced by photosynthesis provide the energy and building material for ecosystems.

SOURCES: Campbell book and wordle.net

Cell Wordle

Wordle: Untitled

The importance of these few chapters is that we know that prokaryotes were the first organisms on Earth. From there we are able to see that the Bacteria and archaea are the two main branches of prokaryote evolution. Nearly all prokaryotes have a cell well external to the plasma membrane. In order to tell if a bacteria is gram-postive and gram-negativem we can do a gram stain. Bacteria differ in the structure of their walls when we try to distinguish between the gram positive and negative.. Prokaryotes can be grouped into four categories according to how they obtain energy and carbon, this is how we have groups like the photoautotrophs, chemoautotrophs, photoheterotrophs, and the chemoheterotrophs. All fungi are heterotrophs and they acquire their energy and nutrients by absorption. The importance on fungi is that ecosystems depend on fungi as decomposers and symbionts. Without fungi and bacteria as decomposers, communities would not have the blessing of chemical recycling.

SOURCES: campbell book and wordle.net