Friday June, 4th, 2010

Last Class, we started talking about the body...

We looked that for scientists, the body has many points of view, or "planes"

If we were to look it from the front, and we divide it "vertically" into 2, we would call it "Sagittal PLane" Left + Right

If we were to look it from one side, and we divide it "vertically" into 2, or parts would be "coronal plane "dorsal + ventral"

-dorsal stand for the "back" part, and "ventral" stand for the frontal part of our body

If we were to look it from the front, and we divide it "horzontally" into 2 we would call it "transverse plane" up + down

After that, we saw many scientific concepts for the location of parts of the body:

locations

distal: far from

closal: clase to

craneal: to the superior part, or "to the crane"

caudal: to the feet

movements

medial: any extremity going to the body's midline

lateral: away from midline

After this concepts and stuff, we started with the skeletal system B)

We have around 206 bones, and our skeletal system mainly divides into 2 parts.

Axial Skeleton + Appendicular skeleton... ;D

The axial skeleton is conformed by the craneum and the spine, ribs and sternum

The Appendicular skeleton is conformed by Limbs, gidles, and its waht sticks to the axial skeleton.

There are several arrangements or classifications in the bones, there are considered in 4 classes:

Long, Short, Flat, irregular and Sesamoid bones...

The first ones, long bones, are called like that because they are "Long" and one of their characteristics are that they are semi-flexed, to resist pressure. They are mainly find y legs, and arms.

The other ones, the short bones are a bit shorter, and they are mainly founded in foot structures and tarsals, structures of the hand.

Flat bones: Characterized because their "large" area and almost no thickness, for example ribs, sternum, and bones from the craneum...

Irregular bones: With no defined shape, and may function like the other 3 mentioned, for example vertebraes, scapula, heel bone, etc.

Sesamoid bones: This ones, are not officially considered, because of their size, they are like one "sesame seed" and many people have more than others, for example, athletes have more than normal people.

Victor Correa

Monday May 31st

Well last class we saw aneuploidies that is a mutation that ocurrs in a whole chromosome.

But first we need to knowe that the smaller the number of chromosome the bigger it is, and that a monosomy is one less chromosome and trisomy is one extra chromosome.

First we saw down syndrome that its a trisomy in chromosome 21 some symptoms of these disease are the overgrowth of some organs, they are mentally challenged, they have a bigger tongue, shorter neck, mongoloid eyes, just one line across its hand, thay cant have kids but they can live several years, and its the most common trisomy.

http://www.youtube.com/watch?v=ycrPCTP2mFE


Then we saw edwards syndrome that its also a trisomy in chromosome 18 some symtoms of these disease is that they overgrowth their head, they have lots of neurological diseases, they live in average 5 to 15 days, thay have malformations, heart delays, breeathing difficulties, and muscle contractions, and they are legal for abortion.

http://www.youtube.com/watch?v=BVdzIywvE_Y


Then we saw prader-willi syndrome that is a deletion of almost an 80% of the mothers 15 chromosome and these kids are always hungry but it dosent mean that they need to be fat if they receive the correct treatment, they present short neck, short ears, mentally challenged, they have very weak muscles,and they can have a normal regular long life.

http://www.youtube.com/watch?v=91_x7fEzh5o

Then the klinfelter syndrome that deals with sex chromosomes XXY that its a male that in puberty they start presenting secondary women features, but it dosent affect anything healthwise.


http://www.youtube.com/watch?v=coGty5bqs4A

Then we have a very rare syndrome that is called the turner syndrome and they just have an X chromosome and they look like kids all their lives, they dont develop their sexual features, there neck is not completely defined.

http://www.youtube.com/watch?v=JVq8lcCqY-A&feature=channel

Then we have the most shocking syndrome that its the patau syndrome and basically these kids dont survive and maximum they live two days, thay have malformations, 6 to 7 fingers,and sometimes they have ciclod eyes.


http://www.youtube.com/watch?v=W9wUkPYJD5I&feature=related

Then we saw three syndromes first trisomy 22 and these kids dont survive at all cause thay have spontaneous abortions, then the XYY sindrome which we call the super macho and they just have and extra Y chromosome and are a little big taller with no health problems, and XXX syndrome in which nothing happens.


Then we have the angelman syndrome that is a deletion in chromosome 15 they have mental difficulties, they are always smiling and happy, and their father chromosome is deleted, they cant cry.

http://www.youtube.com/watch?v=RHastPSc9XQ

Naneth Lopez

Monday May 17th

Today´s class topic was Nucleic Acids. We already know some things about this topic, since last semester we talk about it.

There are two types of nucleic acids:

-DNA (deoxyribonucleic acid): Formed by 2 strands.

-RNA (ribonucleic acid): Formed by 1 strand.

In DNA the two strands (nucleotides) are joined by hydrocarbons and together with water make them twist, giving the helix form to DNA.

DNA goes through 3 processes: Replication, Transcription and Translation.

This process happens when mitosis happens, because the new cells need of DNA in its nucleus.

In replication what happens is that the helicase gets untwisted and gets separated into 2 strands. When the 2 strands are getting separated small pieces of DNA called primers get stick at the end of hydrocarbons so that the hydrocarbons don´t get back together and form again a double strand. After this, the DNA polymerase this means that then each strand gets a ¨copy¨ and the result are 2 double strands.

http://library.thinkquest.org/C006188/basics/pictures/dna_replication.gif

This is part of a semi conservative model since we can say that the resulting DNA has one part of the ¨parent¨ and the other half is a copy, so, it isn´t completely modified or created.

Next, the transcription process takes place in the nucleus and consists of lots of steps, but here they are simplified:

-Iniciation: When the 2 strands start to open.

-Elongation: When the RNA poly opens.

-Finalization: Ending of transcription.

Even it looks like the words are written wrong, they aren´t this are words scientists commonly use.

In transcription, RNA polymerase is needed so that the DNA can turn into RNA.

Finally, translation is when the RNA turns or is translated into proteins.

Stephanie Sotelo

Friday may 7th, 2010

In humans, there are 23 pairs of chromosomes, 2 of them determine the sex of the human, “X”, and “Y”. The X chromosome is bigger than Y; the combination of these two will give birth to a boy or girl.
XX= Female
XY= Male

The sperm possessed both X and Y chromosome, while the ovum only the X one, you cannot say that the Male determine the sex of the kid, although it has both X and Y, he cannot control whose going to combine with the other X chromosome, there are some experimental test, which involve “training” of the sperm, so you could manipulate and determine the sex.

(It’s impossible to combine a YY chromosome, because the ovum only possess the X)

Co-Dominance

It is when both alleles are “Dominant”, and both characteristics are shown on. For example:

Blood type.
A is Dominant, B is Dominant, but O is recessive, when A and B combine, you have a AB blood type, but if you combine A or B with O, then you won’t have an O blood type, since is recessive, you need to combine both O, so you get a O blood type:

	A	B
A	AA	AB
O	AO	BO

A woman (AB), marries a man with (A; Heterozygous), what is the chance of the baby to have O blood type?

Answer: None, there is a chance of having A: 50%, B: 25% and AB: 25%

A always win over O
B always win over O
A always share over B
O need another O

AB= Universal Receptor; Since it has A and B blood type, you can add A or B blood, and the body will accept this blood since it has information about both types.

O= Universal Donor; O blood type doesn't have any antibodies on the blood, so you can give this blood to A, B and AB, but it isn't always sure, there is still a slim chance of an allergic reaction to this blood type, so it's save as last resort.

Xavier Gomez

April 26th and 30th, 2010

After 3 weeks of vacations we finally return to school, we make a quick feedback about vertebrates, (living organisms with a spinal cord, bones and a skull).

We start with a new topic “Genetics”, what is genetics? It is the science that studies how features are passed down to one generation to another, Gregor Mendel was the first one to discover how genetic works by his study of pea plants, he crossed different types of pea plants and he realized that the results have something very similar with the plant’s parents, “traits”, or “features”, which were a group of characteristics that match with the parents. Mendel used pea plants because of their easy grown of large numbers and easy manipulation, set aside, they posses male and female reproductive organs. He also noticed “allele”, Dominant and recessive, Dominant means that the trait will appear always, and recessive that the trait will appear sometimes only, not in all generations. For example, a long time ago dogs, didn’t have a determine race, so what they did was crossed dogs that have a similar trait, sometimes the result didn’t have the same characteristics as their parents because the allele was recessive, so they keep on crossing until that trait became Dominant.

Mendel used the principle of probability, (chance of a possible event) to understand how genetic works, the chances of the plant to have a tall stem, the chance of the plant of having a different color, etc.

The concept of true breed also comes in here; it means that all future generations will share a certain trait.

Pea plants are self pollinating ;)

-True breed of pea plants
-Seed shape (Round-wrinkled)
-Seed color (Yellow- green)
-Seed coat color (gray-white)
-Podshape (smooth- constricted)
-Pod Color (green-yellow)
-Plant Height (tall-small)
-Flower Position (Axial-terminal)

If both the organism has both alleles (ex: T=brown eyes and t=green eyes) Tt, then the dominant “T”, is the one that will prevail.

Homozygous means that the organism has both of the same alleles (TT or tt)
Heterozygous means that the organism has different alleles (Tt)

T= Tall, t= small	T	t
T	TT=The organism is going to be tall	Tt= The organism is going to be tall
t	Tt= The organism is going to be tall	tt= The organism is going to be small

Example:
If Daniel has Brown Eyes (Heterozygous), and has a baby with a woman with green eyes, what’s the chance of the baby to have green eyes?

Tt tt ß if recessive prevails, it CANNOT be heterozygous (Tt: REMEMBER THAT IT’S JUST NEEDED A DOMINANT FOR LOSING IT’S GREEN EYES)

T= Brown,t= Green	t	t
T	Tt=The baby is going to have brown eyes.	Tt=The baby is going to have brown eyes.
t	tt=The baby is going to have GREEN eyes.	tt=The baby is going to have GREEN eyes.

Answer= 50%

Here’s is a table of some characteristics which are dominant or recessive:

Dominant	Recessive
Freckles	No Freckles
Dimples	No Dimples
Curly Hair	Any other type of hair
Dwarfness	Normal Growth
Free Earlobes	Not free
Role Tongue	Cannot role tongue
Second toe larger	First toe larger

Xavier Gomez

Friday march 12th, 2010

Last class, we talked about spongebob, pokèmon. a bug's life and biology stuff 8)

Mollusca..!
All molusks have like a soft-body that is like jelly-like meat. They have a shell in a specific part of their body.
-There are 7 groups, we're talking about 3 right now...
Gastropods...
In gastropods we can find animals like the snails. They have one single "foot" that they use to move. Regularly, gastropods are herbivores. They have a "radula" that is like a small tongue used to "scrape" rocks to get herbs and get feed.

Bivalva
Bivalva are the animals that have two shells, like clams. They have a muscle that gets both shells, and it can either
close it or open. They have a foot, that is what we see when we open them. Then use it to move or flee from danger.
They have a special "tissue" that they use as a net, or a filter, in which food gets stuck in there, so the bivalve eats.
Shelder and Clampearl can throw water through their foot. I dont know how can they do it, but is SUPER effective versus
the fire types and not -very effecive versus ICE types... ;B

Cephalopoda
These ones have an inner shell. They have their skin, and under the skin they have their shell. For example, the nautilus, the squid. -The squid has its shell in its "forehead" they, under the forehea they have its foot, and then, they have tentacles, used to swim or grab stuff..
The nautilus is seen as the one of the "most" dangerous hunters of the animals, because inside its shell, it has chambers, in which they contain air, and the nautilus can control the pressure inside them, so they can either go up, and down, and they are good preparing traps for preys.



Arthropods
This "phyllum" is the most nomerous in all the eukarya domain.
-We find that they share many characteristics.
*Exoskeleton
*Segmented
*jointed appendages "legs"

SPIDERS AND FRIENDS...
They are called "chelicerates"
-This because the shape of their mouths.
They have 4 pairs of legs and they divide into 2 segments.
Many examples of these ones are spiders, mites, scorpions, Horseshoe crabs
I like the wolf spider

Crustaceans and bff's
they are called decapoda
-They have a carapace, that this is that in a specific part of its "exoskeleton" they have a VERY thick part, like in
lobsters, crabs, etc.
They have a head, 2 antenae and 3 segments, "head, cephalotorax, thorax"

INSECTS AND FELLAS..
these animals hano no branched appendages.
They have jaws and 2 antenae.
*the centipede
*milipede
*Insects..
One of the processes of them is the "molting" is like their "skins"gets too old, and inside of them, they create a new "insect" so when it is time, they can come "out" of their old skin and be the same-other insect..
cool :D

Victor Correa

Monday March 8th, 2010

This class we talked about a particularily interesting kind of animalia, and they were:

· Sponges

· Cnidaria

· Platyhelmynths

· Nematode

· Annelida

Sponges (porifera)

These are nothing like the sponges you see on TV. These are completely still and unmoving, in fact they have calcium in them, so that tells you just how still they are.you may ask yourself, how do they feed then? Well its very simple. They clean water. Water rushes through them and as it does the sponge…does what a sponge does. Absorbs the nutrients it needs.

That’s just one kind of sponge though. The other kind uses flagella. 0.0 This one is not so still. It uses the flagella and spins it in order to make a whirlpool, and force or actually suck the water in.

Cnidaria (jellyfish-anemone)

These have 2 layers of skin, the outside one is used for protection, and the inner one is used for digestion.

Now you may know them as “aguamalas” but those are just one of the different species of jellyfish. Cool thing about these is that they can reproduce both sexually and asexually, one generation does it sexually and the next asexually. This is called alternance of generations. Now about the burns of these,they are caused by “nematocistos”, which are like stingers activated by a nerve when it is stimulated. Even when it dies, the trap set up will still work. Which is cool.

Not much to say about anemone. They are the house of clownfish (nemo), but actually have toxins and other stuff to trap little fish. They are stuck on the ground but can move their tentacles in order to trap its prey.

Platyhelmynths (flat worms)

These are the first to have a cephalic region, which is considered a head, a group of nerve cells.

They also have bilateral symmetry, which means they have a left and a right and a top and bottom…although they poop through their mouth.

They are turbellarians, meaning they eat microalgae

These also happen to have blood

And finally, with these come the famous tapeworms (cestoda)

Nematoda (roundworms)

These are nonsegmented worms

They are parasytic, meaning they need a host to get their nutrients from and live, they also do elephantiasis, which means they get inside of you to get what they need. These have a separate mouth and anus, which is a relief for them I imagine.

Annelida (leeches)

The last but not least are the annelid, which are divided in three different groups:

Oigochaceae, hirudinea and polychaetae

Oigocahetae consists of earth worms

Hirunidea, my preferred kind, consist of leeches…woot!, which are obviously parasitic. They can only live in fresh water though

And finally come polychaetae, which are made up of lots of chaetae, duh. These are rings, used to make the worm advance and move by contracting and expanding over and over again.

Fernando Lopez Almada

Monday March 1st, 2010

Today's class contained a lot of topics:

~ Antibiotics ~

- What's an antibiotic?

It's a substance that kills bacteria.

*Diseases caused by bacteria are called infections.

Antibiotics work by destroying the junction between two molecules which compose the bacteria's cell wall.

Those two molecules are called:

1. NAM

2. NAG

Antibiotics are made for an specific type of bacteria. Wide Spectrum antibiotic is a special antibiotic which destroys every bacteria it makes contact with; it's used when doctors are not sure of what bacterium caused the infection.

~ Eukarya Domain ~

- Animalia

- Plantae

- Fungi

- Protista: Any eukaryote that is not an animal, plant or fungus; in other words, those organisms which don't fit in any of the other categories.

The Protista kingdom is composed by three main phylums & their own classes:

1. Algae

a) Red

b) Green

c) Brown

d) Yellow

e) Dinoflagellates

2. Protozoans

a) Sarcodias

b) Flagellates

c) Cilliates

d) Sporozoans

3. Molds

----------------------------------------------------------------------------------------------

***Algae***

[ Dinoflagellates ]

- Two flagella

- Cell wall

- One flagellum covers the cell wall, while the other one works as propellant

- Most of them live in the sea, and they're food for other organisms

- Some of them are bioluminescent

- They cause the red tide

- Red tide happens when they reproduce excessively; & the sea gets a red-ish color

[ Red ]

- Most of them are marine

- They're in tropical zones

- Multicellular

- Red color (duh)

- They absorb light & it filters to the deepest zones of the sea

- They contain chlorophyll

- They're food for heterotrophs

- They form calcium depots

- They contribute to form reefs

[ Green ]

- It has that color because of a & b chlorophyll

- They live in fresh water

- They produce oxygen

- It can either be unicellular or multicellular

[ Brown ]

- They're found on the sea & seashores

- They're used to make cheese, cream & cosmetics

[ Yellow ]

- They're also known as golden algae

- They have that color because of a pigment called fucoxanthin

- They contribute to photosynthesis

***Protozoans***

[ Flagellates ]

- One or many flagella

- They live in freshwater, salt water & wet soil

- They can live in symbiosis

- Some of them are parasites

- They're from the group "Filum sarcomastigophora"

[ Sarcodias ]

- Similar to amoeba

- They live in freshwater & salt water

- For feeding they surround the microorganism & form a vacuole

- They're known for having beautiful shapes

[ Cilliates ]

- They're the most complex because of their structure

- They move because of cilia

- There's the presence of a frame & a micronucleus

- The frame controls the cell's functions & the micronucleus its reproduction

- They have a contractile vacuole to eliminate water excess

[ Sporozoans ]

- They're infectious spores

- They're transmitted from one organism to another

Jorge Dominguez

Viernes 26 de febrero del 2010

We saw the last of virus by knowing of a few diseases caused by them. Along with the type of virus, symptoms, and type of nucleic acid the virus had.

Also, we saw of vaccines. A way of protections against viral diseases, it basically involves applying the virus itself so that the immunological system can prepare itself and be capable of protecting the body from future attacks. There are three types of vaccines. One involves just letting in pieces of the virus. Other involves inserting an inactive virus. And the last, involves inserting a virus, that though it can still act, it's been weakened to minimize problems.

Finished with that, we moved into bacteria. Bacteria compose two of the three domains of classified organisms: Eubacteria and Archaeobacteria. The Archaeobacteria are composed of the primitive bacteria, who had been living longer than the rest of the organisms. This is due to being able to survive in the extreme conditions the Earth was all those years ago. Mainly, there are the thermophyles, who live in very hot places; acydophyles, who live in very acid places; methanogenic, who live in places with lack of oxygen; and halophyles, who live in very salty places. Fortunetly, since they can't adapt to conditions not as extreme, it's guaranteed they can't really do much outside of them, which means that if they were the source of deseases, they can't affect other living organisms since or else they die before having the chance. So, archaeobacteria are harmless, or rather, aren't able to harm us in any way if they could.

The Eubacteria are more recent, and also the most common kind of bacteria. These can cause diseases on other living organisms. There are many of these. The structure of a bacteria is, being a cell basically, that of DNA covered in citoplasm, and also contains ribosomes. Like plant cells, they have a cell wall, and for movement they contain flagellum to do the task. One fact of bacteria is that if they ever find themselves low on resoursces, they would cut their flagellum, cover themselves with an extra outer cover called Endospore, and basically, go into 'hibernate', so to speak. They won't 'wake up' until conditions and resources return to normal. How long they can last like this is not entirely sure. But, there has been bacteria like this found in the ancient Egyptian pyramids that were able to 'revive'. Which means they are capable of lasting for a few thousand years at most.

Last, we saw a few differences between the two groups. First, eurobacteria have clycerol and fatty acids in the membrane. Their wall have proteins and carbs, while their RNA is unique in itself. On the other hand, archaeobacteria have glycerol and hydrocarbons in the membrane, glycoproteins in their wall, and their RNA is eukaryote-like.

Juan Manuel Aguirre

Monday February 22nd, 2010

Today´s class topic was: VIRUSES.

A virus has no cell which means that the virus is not alive. Viruses can have DNA or RNA, based in this, scientists classify them. When it has RNA are called retroviruses and are very harmful. Other components of a virus are:

-Proteins: Is a coat that protects the nucleic acid.

-Envelope: Made of carbs and is kind of mucous or sticky.

-Spikes: Located between the protein coat and the envelope. Spikes and the envelope of carbs work together in order to stick into other cell.

-Projections: To get stock to other cell. Have an appearance of little legs.

A virus floats inside the body of the organism in which it is (chicken, cow, human, etc.) until something stops it, so it attaches to that thing, in this case a cell for getting able to duplicate.

Something important to know is that a virus of other organism can affect a human, for example, a chicken virus can´t affect a human it just affects chickens.

There are 2 ways or forms of viruses to duplicate: LYTHIC CYCLE and LYSOGENIC CYCLE.

LYTHIC CYCLE: Lythic means destruction. It destroys the cell.

Steps:

1.- Virus attaches to the cell.

2.- It inserts DNA.

3.- The DNA gets to the nucleus. (Ehen the virus DNA gets to the nucleus, the cell DNA stops working, it is like if it deactivated the cell DNA).

4.- The cell is HIJACKED.

5.- It gets out (Inside the cell the viruses duplicates, and duplicates, and duplicates… until the cell its full of viruses and explodes, there is when each of the viruses gets to infect the nearest cell).

LYSOGENIC CYCLE: it can be familiarized as SPY CYCLE*.

Steps:

1.- The virus gets attached to the cell.

2.- It inserts its DNA.

3.- The DNA gets to the nucleus.

Up to here the first 3 steps are the same to the lythic cycle but the next 2 change.

4.- The DNA of the virus hides in the nucleus.

5.- When mitosis of the cell happens the result is 2 cells with DNA and virus, INFECTED CELLS.

*Spy cycle is not an official name for this cycle is just an example or an easier way to understand this cycle. With SPY it means that the virus gets silently into the cell and it starts getting the cell weaker and weaker until it duplicates by the mitosis of the cell.

Some words definition we saw really fast are VIROIDS and PRIONS.

-Viroids: Are biological agents with little RNA.

-Prions: Are proteins that cause disease.

Stephanie Sotelo