Homologous Chromosomes = two versions bearing genes for the same set of characteristics.

Meiosis= type of nuclear division that differs from mitosis in 2 ways: (1) meiosis is gamete-producing process, in which primary germ cells become mature gametes for sexual reproduction, (2) meiosis consists of 2 nuclear divisions, in which the chromosomes divide only once but the cell cytoplasm divides twice, producing four cells (w/ only half the original # of chromosomes making it haploid).

Gametogenesis= the process of forming mature gametes from primary germ cells and involves both meiosis and mitosis.

Maturation process= the final divisions necessary to produce functional ova and spermatozoa.

Meiosis I=
-Interphase: DNA replicates. Homo Chroms. Exchange genetic material through crossing over. They then separate to opposite poles of cell. Each of the 2 resulting cells have half the num. of chromosomes present in diploid stage. However, they do have 2 sister chromatids joined at their centromeres. Chiasmata is the connecting point btw homologous chromosomes.
-Prophase I: Crossing over occurs and spindle forms.
-Metaphase I: Kinetochore from opposite poles attach to homologs.
-Anaphase I: Pairs are pulled apart as Kinetochore shortens.
-Telophase I: separated homologs cluster at opposite poles and nuclear membranes reform. Cytokenesis may occur.

Meiosis II=
-Prophase II: new spindles form and nuclear membranes breakdown.
-Metaphase II: sister chromatids line up. Kinetochore microtubules from opposite poles attach to opposite sides of centromere.
-Anaphase II: centromeres are split and pulled to opposite poles of the cell.
-Telophase II: nuclear membrane forms around 4 clusters. Cytokenesis occurs yielding 4 haploid cells.

Spermatogenesis= gametogenesis in the testis (development of spermatozoa).
-Primordial germ cells= somatic cells that will eventually migrate to the developing gonads and begin to multiply by ordinary mitosis. These cells migrate to the testis and become spermatogonia (diploid) as the multiply by mitosis.
-PGCells (some of them) mature and become primary spermatocytes.
-Meiosis I occurs.
-Two daughter cells (2ndary spermatocytes) are produced.
-Meiosis II occurs.
-The daughter cells (4) that result from the division the 2ndary spermatocytes are called Spermatids.
-Spermatids undergo cytodifferentiation, producing spermatozoa. =Spermiogenesis

Oogenesis: gametogenesis in the ovary.
-Primordial germ cells become oogonia, which increase in mitosis. Some enlarge to become primary oocytes, which undergo meiosis.
-The primary oocytes produce a shell to prevent penetration from other spermatozoon once it has already been penetrated.
-Meiotic Division I:
*synapsis occurs and the homologous chroms (make up a bivalent).
*metaphase occurs. Chroms lined up on a spindle.
*egg reaches Telophase and division is almost complete. One dyad from each bivalent will go to each daughter cell (2ndary oocytes) and one of the daughter cells will retain all the cytoplasm while the rest of the cells are pushed out and become the first polar body.
-Meiotic Division II:
*in the 2ndary oocyte the 2 dyads divide throwing off 2 chromatids in the 2nd polar body, which like the 1st has no cytoplasm and nonfunctional.
*The remaining 2 chromatids still in the egg become a mature ovum and take part in the formation of the female pronucleus. Each mature ovum is haploid.
*the membrane from each (male & female) pronucleus disappears. 2 chroms from each move to spindle and the 1st cleavage division occurs. The chromosomes line up in metaphase. This is the 1st set of a series of mitotic (cleavage divisions) that will occur to produce the new embryo.

Cleavage Patterns

-irregular vs. regular
*irregular= different sizes
-complete (holoblastic (amphibians))
*spiral cleavage (mosaic – cells fit into a predetermined location in the larval body) (all groups showing this type of cleavage belongs to the phyla Protostomia)
*radial cleavage (regulative – cells don’t fit into a predetermined location in the larval body)
-incomplete (meroblastic (birds and reptiles))
*discoidal is when cleavage is restricted to a small disc of cytoplasm on the animal pole because the animal had extreme telolecithal eggs. (Belong to the Deuterostomia in which the mouth is formed from a 2ndary embryonic opening)
-superficial (insects)
*regular=egg cytoplasm is segregated into specific cells called blastomeres occupying discrete positions and having specific developmental fates.

~Spiral Cleavage:
*Nemertea (phylum) undergo spiral cleavage. Round worm**
Stages:
-Unfertilized ovum (diploid)
-Fertilized undivided ovum (haploid) – after the female & male pronucleuses fuse it is now a zygote.
-Cleavage of zygote: blastomeres produced are in equal size.
*1st cleavage: 2 blastomeres
*2nd cleavage: right angles 4 blastomeres
*3rd cleavage: equatorial plane 8 blastomeres- 4 micromere in animal hemisphere- 4 macromeres in vegetal hemisphere. Spiral cleavage occurs because the spindles are oriented obliquely.
*4th cleavage: 16 blastomeres.
*Morula stage: blastomeres become too numerous to count.
*Blastula stage: blastocoel appears and surface of blastula is covered in cilia.
*Gastrula stage:
- An indentation appears @ the vegetal pole. Invagination occurs to form the internal cavity, the archenteron (the gut). Blastopore forms the mouth.
- The embryo can now swim inward through the archenteron. The gastrula is now an embryo of 2 germ layers. Ectoderm (outer layer and gives rise to the epithelium) and Endoderm (lining the archenteron and gives rise to lining of the digestive system).
-mass of cells that arise in the blastocoel in the later stage give rise to the 3rd germ layer mesoderm, which form the muscles, blood vessels, and reproductive system. The mesoderm mother cell is what gives rise to that mass of cells.
-The blastopore has now sunk inward to open widely into the archenteron (the gut). This is the pilidium larvae stage.

***Radial Cleavage (Sea star – phylum Echinodermata)

-Cleavage Stages:
*Unfertilized Ovum
*Fertilized undivided ovum: male & female pronuclei fuse and a fertilization membrane appears.
*Cleavage stages:
-1st & 2nd cleavage: perpendicular cleavage
-3rd cleavage: through equator
-Morula stage: 16 or more cells. w/ no large cavity in the center.
-Blastula stage: cells arrange themselves around a central cavity (blastocoel). The embryo develops cilia towards the end of this stage and becomes free swimming.
-Gastrula stage: Invagination begins and forms the archenteron (endodermal lining of the digestive tube) and blastopore (anus). Cells streaming inward by Invagination to form the archenteron give rise to the endoderm and mesoderm. The ectoderm face and spread downward toward the blastopore by a morphogenetic mvmt. Called epiboly. Coelomic vesicles are the origin of the mesoderm that will give rise to the peritoneum (lining of the coelom), skeleton, and muscular system. They will enlarge and separate to form the coelomic pouches. The mesenchyme cells migrate into the blastocoel.
-Bipinnaria Larval stage: the archenteron bends to meet the stomodeum (mouth). They fuse and perforate to form the mouth. Thus forming from a secondary larval opening. The basic organization is now complete.
-Brachiolaria larva

***Frog Development

-Frog eggs are mesolecithal and shows definite polarity.
-Animal pole = region of the egg just above the nucleus in the darkly pigmented hemisphere.
-Vegetal pole = opposite of the animal pole.
-Bilateral and radial cleavage. The division of the vegetal pole has less cells but larger ones.
-The ova (eggs) are various sizes but contain little yolk and have conspicuous nuclei. Chromatin granules (mix of dna and protein) can be found here. Early germ cells have cell membranes and the older ova have follicular cell layers.
-Cleavage Stages:
*One-cell stage: an unfertilized ovum or fertilized egg (zygote) that has not yet started to develop. There are three layers of jelly:
1.) Animal hemisphere: black and not as heavy as …
2.) Vegetal hemisphere: always floats uppermost in water to absorb sunlight, which is necessary for development.
3.) Grey crescent: it appears soon after fertilization on the opposite side of where the spermatozoon entered. It is produced by the migration of pigmented cytoplasm away from that area.
*Early Cleavage stages: 1st = 2-cell stage (vertical); 2nd = 4-cell stage (vertical as well but @ right angle from 1st); 8-cell stage= macromeres (vegetal) and micromeres (animal).
*Morula stage: 16 to 32 cells – larger number of micromeres to macromeres.
*Blastula stage: begins @ about 32 cells; blastocoel (segmentation cavity) begins near the animal pole.
*Gastrula stage: is marked by a crescent shaped slit. Epiboly occurs (growing of animal hemi. Pigmented cells over the vegetal cells. The opening is called the blastopore. Continue growing until there is only a small mass of vegetal cells left showing (yolk plug). The invaginating cells form the endoderm surrounded by the ectoderm. The mesoderm forms btw the two of them. The blastocoel is eventually obliterated.
*Neural Groove stage: this groove eventually become a tube. There is a neural fold on both sides of the groove. The groove develops in a thick ectodermal plate (neural plate). Just ventral is the notochord.
*Neural tube stage: The groove is now closed and a tube has formed. Eyes develop from the 1st ridges and gills from the 2nd. Ventral suckers on the bottom. Oral plate at the anterior end and the anus @ the posterior end. The masses of mesoderm lateral to the notochord give rise to the dermis, muscles, and skeleton. The intermediate mesoderm give rise to the excretory system; and a thin hypomeric layer surrounds the yolk mass and gives rise to the coelomic cavity.
*Tadpole and metamorphosis:
-the embryo frees itself from the protective jelly and is now a tadpole.
-metamorphosis is the rapid transformation from larva to adult frog.
-after hatching the oval mouth breaks through archenteron, the intestine develops and begins feeding, three pairs of fingerlike external gills grow rapidly, and gill slits appear which are eventually replaced by internal gills. As the external gills disappear the opercula arises on both sides of the head over the internal gills and eventually fuse to make a chamber for the gills. The spiracle is where the water that goes through the gills is released from. Ventral sucker, which is used to adhere to vegetation, divides and degenerates. Legs, lungs, and etc. form until there is now an adult frog.

Chapter 4: Histology

- Tissue: an aggregation of cells and cell products with a common function.
- Histology: the study of tissues.
- Organ: aggregation of tissues into a larger functional unit; organs work together as functional units called systems.
- 4 major groups of tissues:
o Epithelial
 Glandular cells: function in fluid secretion.
 Endothelium: when epithelial tissue lines the inner surface of the heart, blood vessels, and lymphatic vessels.
 One surface of tissue tends to be free while the other rests on vascular connective tissue.
 Derived from all three embryonic layers and main function is protection, but also secretion, excretion, absorption, lubrication, and sensory perception.
 Two types of epithelium:
• Simple Epithelium
o Simple Squamous Epithelium
 Hexagonal shape. – specialized diffusion
o Simple cuboidal epithelium
 6-sided but appear square in side view; line tubules & etc. Some have microvilli that increase surface area.
o Simple columnar epithelium
 Rectangle shaped. Sm intestines & secretory surfaces (stomach, etc.) Goblet cells which are specialized for secretion in intestines.
o Pseudostratified columnar epithelium
 Actually simple epithelium with all the cells resting on a basement membrane (secures epithelium that isn’t the same height). (trachea, bronchi, male urethra)
• Stratified Epithelium (two or more layers of cells)
o Stratified Squamous epithelium
 Change from cuboidal basal layer to extremely flattened layers at free surface. – Areas of mechanical abrasion. Surface skin is keratinized (tough, noncellular layer of the protein keratin.
o Transitional epithelium
 Confined to the urinary tract and bladder and is specialized for stretching.
o Connective
 Vascular tissue – transports nutritive substances to tissues and carries away waste.
• Blood
o Erythrocytes – hemoglobin; circulate freely
o Leukocytes – pass through cell walls and ingest foreign particles and invading organisms (phagocytosis). Key role in immune responses.
o Blood platelets
 Clot-promoting bodies found only in mammals. In non-mammals they are called thrombocytes.
• Lymph
 Fibers
• Connective tissue is made of extracellular fibers embedded in the structureless ground substances (matrix).
• Three types:
o Collagenous fibers – thick, wavy bundles of finer fibrils.
o Elastic fibers – thin, yellowish, branching threads.
o Reticular fibers – inelastic.
 Two types of connective
• Loose connective tissue (underlies epithelial tissue)
o Areolar connective
 Loose fibroelastic tissue; most widespread. Small spaces and found throughout body (fastening skin, membranes, vessels, and nerves.)
o Adipose connective
 Specialized for storing lipids.
• Dense connective tissue (major supportive functions)
o Sheaths
o Ligaments
o Tendons
o Cartilage
 Hyaline cartilage – most common form. (ends of bones, nose, trachea, and other places, etc.)
 Lacunae scattered through out the ground substance.
o Bone
 Most specialized in supporting of all connective tissues. Protects organs and framework of body.
 Matrix is heavily infiltrated by calcium and phosphate deposited by the action of bone-forming cells called osteoblasts.
 Structure of the bone:
• Compact bone surrounds a bone marrow cavity.
• Compact bone is made up of osteons, each built around a narrow canal containing blood vessel.
• Osteoblasts are arranged in the matrix around blood vessels in layers called lamellae. Each osteoblasts occupies a space called lacunae.
• These cells have branching process which make canaliculi, tiny channels which nourish the cells in the bone from the blood supply.
• Enlarged ends of the bone are made of spongy bone and the entire bone has a thin layer of connective tissue called periosteum. Nerves and bone penetrate and nourish bone.
o Muscle
 Three types of muscle
• Smooth muscle (visceral muscle)
o
• Skeletal muscle
• Cardiac muscle
o Nervous



He was Lord Voldemort, the greatest sperm cell ever! He could and would defeat all the other male gametogonia that tried to get in his way of developing into the most powerful, honorable, fast, and mature sperm to have ever existed. He pushed and shoved his way past that annoying Albus Dumbledore and Harry Potter.

He would beat them! He would! He’d be the first and the best!

When The Great and Amazing Lord Voldemort finally felt himself in the optimal conditions in the seminiferous tubules that he had planned and plotted all this time for he began to change – he could feel it!- into a diploid spermatogonium. Hah! Beat that Harry Potter and Albus Dumbledore!

Waaahhh! Potter and Dumbledore are also spermatogonium! No fair – I was first!

Slowly, but surely The Great And Amazing Lord Voldemort began moving away from the walls of the tubules and into the innermost part. As he moved inwards he continued to change. First, into the Greastest, Most Powerful Primary Spermatocyte. Then into the Most Marvelous and Evil Seconday Spermatocyte. Eventully into an Awe-inspiring spermatid. Then last but not least into the Greatest and Most Amazing spermatozoa to ever be seen!

Lord Voldemort was not happy. For Harry Potter and Albus Dumbledore had also developed into spermatozoa! That wasn’t the worst of it though! Hundreds, a great many other insignificant stem cells had also developed into immature sperm! Lord Voldemort was very, very angry. He calmed himself with the thought that even though those worms had managed as well that he would still be THE GREATEST MATURE SPERM EVER!!!

So with that inspiration Lord Voldemort continued on his journey and traveled to the epididymis where he matured into the MOST EVIL AND GREATEST MATURE SPERM EVER!!!! And now he was stuck waiting here with Albus Dumbledore, Harry Potter, and about a thousand other insignificant, weak worms…..

Total crack fic, despite the fact that I’m not on crack or any other drugs. This popped into my head when I was studying for Zoology and I thought what the heck! It might just be amusing, more fun than studying….

It starts off with Honda Tohru. We learn that her mother died recently in an accident and that she doesn’t want to burden anyone so decides to live on her own in a tent in the middle of a forest. A week after having lived in the forest Honda comes across a house in it and finds herself drawn to some figurines made of the chinese zodiac animals found on the porch. She then meets one of men living in the house, Shigure. They begin talking about the chinese zodiac animals and about a tale her mother would tell her as a child. The tale spoke of god inviting all the animals to a party and mouse chinese zodiac animal tricked the cat into beliving that the party was being held on another day. All the animals got to have a good time at the party but the cat. Honda sympathizes with the cat. Honda then learns that Sohma Yuki-kun, her crush, is that man’s cousin. Sohma offers to walk her to school.

After school Honda overworks herself and she finds herself going home to her tent with a fever. Yuki-Kun and his cousin take Honda in after a landslide takes her tent and her possessions. While Honda is sleeping Yuki-Kun returns to the tent and digs up Honda’s precious picture of her mother and her other belongings. When Honda wakes up she offered a room in the Sohma household. When shown her room a boy (named Kyou) comes crashing in from the ceiling and then tries to attack Yuki. In order to stop him Honda grabs him around the waist and he suddenly turns into a cat. Eventually in a complete chain of events she ends up hugging Yuki (who turns into a mouse) and Shigure (who turns into a dog).

Basically, the anime was about this supposedly normal boy Ueki Kousuke. Ueki was given the power to turn trash into trees by his middle school teacher Kobasen. Kobasen is a Heavenly Being who was sent by God to chose a middle school student to play in a game for the ultimate prize- a blank Zai.

Zai is a personal ability (Charm, intelligence, reunion) that each of the middle schoolers have. They each start out with eleven. Every time they attack somebody that wasn’t given powers to by someone like Kobasen they lose one of those Zai. When they reach zero Zai they disappear. However, everytime they beat somebody that was appointed they gain a Zai from that person. The person that was either knocked unconcious or killed loses the Zai but is also out of the competition. A blank Zai allows a person to choose any personal ability they want to gain.

Unfortunately, Ueki has trouble not attacking and loses Zai constantly, even with Mori there to try to keep that from happening. Ueki eventually attracts the attention of the most powerful player, Robert. Kobasen is sent to hell, however, for breaking one the rules set up by god – he was not allowed to interfere in any of the fights. Robert is the son of one the Heavenly Beings, which makes him a Heavenly Being as well. Ueki then learns that he is also a Heavenly being and trains to defeat Robert’s Ten (ten of the most powerful players who swore alliegence to Robert) and Robert by learning the extra powers he can use as a Heavenly Being. When finally Ueki battles Robert and basically convinces him that justice does exist Robert’s body is possessed by one of the bad guys. Ueki and his group of friends then begin the next trial after there are only 25 more players left in the game.

In Round two, Ueki and team are given the chance to pick a popsicle. Ueki being exhausted and hot grabbed the biggest one before he could be stopped. Thus, causing them to all fail. This forced them to play Round three where they had to fight several other groups. Once winning round three Ueki and others are all ready to fight possessed!Robert. Unfortuately that doesn’t happen. Robert ends up being eaten by Anon. Now Anon has both the powers of a Heavenly Being and that of one of the players. When Ueki and Anon fight in the final battle he spits Robert back up so that he no longer one of the players and thus everytime Ueki hits Anon he loses Zai. He has a total of 18 Zai. Believing that he only has one more Zai left Ueki attacks Anon and wins. Luckily during the battle one of Ueki’s attacks hits one of his teamates and he gains one extra Zai. Ueki wins the blank Zai. He makes it a Zai of reunions so that he can once more have a reunion with Kobasen.

Davis then realizes that everybody has ditched him and lucky him he can follow them on the moving mini island thing. Tk while helping to release the prisoners sees on the TV screen that Ken is trying to collect Devimon. Tk remembers Devimon from his first trip in the digworld when he was younger and how his digital partner had to sacrifice himself in order to save them all from him.


Tk upset goes storming off with Patamon and finds Ken who has finally finished his digimon creation. Ken and Tk beat each other up. (Tk beats Ken up more than vice versa)

While in the middle of the fight Tk sees his other friends (Kari, Cody, etc.) fighting the giant (extremely tough) digimon that Ken created and ditches the fight in order to help them out.

Amou a second year student in the Press club shows up and basically makes it so that Hino has to preform for everyone one more time before the concours. Hino then goes searching for Lilli due to the mishap with the violin, instead she finds a sleeping pretty boy and overhears Len practicing.

Hino then goes to the school roof and starts playing the song (Schubert’s Ave Maria) she just heard Len playing on his violin. Once she finishes the song Lilli shows up and explains that what makes the violin play is her heart. Because she enjoyed the song she heard Len playing she was able to play the song with the magic violin. Lilli then manages to guilt Hino into preforming in the competition although she felt like having the magic violin was cheating.


Kanazawa-sensei then explains to all six of the participants that the concours will be split into four selections. They are ranked for each selection and the finalists are determined by this ranking. Each selection has a theme.

Hino is worried about the whole concours thing even more now. She runs into Tsuchiura-kun (a second year regular student she recently meet that’s in the soccer club.) Tsuchiura tells her that if she ever needs his help to feel free to ask.

Hino begins practicing more and more as the days go by. While trying to figure out why she could play Ave Maria better than all the other songs she’s been practicing she runs into Hihara. She tells him that she’s playing Gavotte for the performance she’s doing for the newspaper tomorrow. He plays it for her on his trumpet and then explains to her that she just has to enjoy herself.


Finally, in the school court yard Hino preforms in front of a small audience Gavotte. About half way through she freezes when she realizes that she’s gained quite an audience.

The following characters are categorized as following:

Earth (leads to the creation of all things):
Guiche D. Gramon, The Bronze – who happens to a total player, and pretty boy summons a mole.

Fire:
Kirche the Ardent summons a salamander. Kirche is extremely well developed as a girl and likes to tease/ pick on Louise for lack of ability to cast spells correctly despite the fact that she’s a noble.

Louise, however, summons a commoner (a human who can’t do magic). To complete the contract she kisses the boy. Turns out he can’t speak their language or understand it. While in her room with him she tries to cast a mute spell on him , it ends up being a translation spell. The boy’s name ends up being Hirago Saito from Japan. Thinking it a crazy cult of some sort he ends up trying to escape and learns the truth.

Episode 2
coming soon…

Hino Kahoko-san was running late for school and stop to take a short break at the front of the school. There she had an encouter with a strange being. Believing it to be her imagination she ran away.

Whenever the bells in the school grounds ring then the contours (a musical competition which determines which student is musically blessed) will take place.

The following were chosen to participate in the concours.
From the Music department:

Class 3-B:
Yunoki Asuma-kun and Hihara Kazuki-kun

Class 2-A:
Tsukimori Len-kun

Class 1-A
Shimizu Keiichi-kun

Class 1-B:
Fuuyumi Shouko-san

From the Regular Department:

Class 2-B:
Hino Kahoko-san

According to Kanazawa-sensei they were chosen because they could all see the faery. Hino after learning that she was in the concours went to speak with him and was given a message to go meet with the faery in the music department. There Lilli the fata (a fairy of music) gave her a magic violin that could make anyone play it.

It seems sort of interesting so far and appears to have some sort of plot coming.