The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. Organisms can be classified as unicellular (consisting of a single cell; including most bacteria) or multicellular (including plants and animals). Humans contain about 10 trillion (1013) cells. Most plant and animal cells are between 1 and 100 µm and therefore are visible only under the microscope.
The cell was discovered by Robert Hooke in 1665. In 1835, before the final cell theory was developed, Jan Evangelista Purkyně observed small "granules" while looking at the plant tissue through a microscope. The cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that all cells come from preexisting cells, that vital functions of an organism occur within cells, and that all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.
Cell biology (formerly cytology, from the Greek kytos, "contain") is a scientific discipline that studies cells – their physiological properties, their structure, the organelles they contain, interactions with their environment, their life cycle, division and death. This is done both on a microscopic and molecular level. Cell biology research encompasses both the great diversity of single-celled organisms like bacteria and protozoa, as well as the many specialized cells in multicellular organisms such as humans.
Knowing the components of cells and how cells work is fundamental to all biological sciences. Appreciating the similarities and differences between cell types is particularly important to the fields of cell and molecular biology as well as to biomedical fields such as cancer research and developmental biology. These fundamental similarities and differences provide a unifying theme, sometimes allowing the principles learned from studying one cell type to be extrapolated and generalized to other cell types. Therefore, research in cell biology is closely related to genetics, biochemistry, molecular biology, immunology, and developmental biology.
Daniel Kraft, M.D. is an NIH funded faculty member affiliated with Stanford. He was on clinical faculty with the UCSF pediatric bone marrow transplantation service and serves as the medicine track chair for Singularity University where he is also executive director for the FutureMed executive program.
Daniel is the founder of StemCor Systems and founder and consulting chief medical officer for RegenMed Systems, a clinical-stage medical device company that develops tools to enable regenerative stem cell therapies. He is the inventor of the MarrowMiner, a minimally invasive device for the harvest of bone marrow derived stem and progenitor cells. This device is being commercialized by Hospira Inc. for use in bone marrow transplantation and by RegenMed Systems for use in regenerative medicine.
Dr. Kraft received a degree in Biochemistry from Brown University and his M.D. from the Stanford University School of Medicine. He completed the Harvard combined residency in Internal Medicine and Pediatrics at the Massachusetts General Hospital and the Boston Children's Hospital, before returning to Stanford for clinical fellowship training in hematology/oncology and bone marrow transplantation and a post-doctoral fellowship with Dr. Irving Weissman. Dr. Kraft is board certified in both Pediatrics and Internal Medicine.
Hello, I'm back again
Haven't seen you since I don't know when
It's been so long but you seem so cold
Is it something you've been told?
She said, "So this is what you think of me
Going with some whore somewhere out in Germany"
I said "Baby, baby can't you see
It's nothing to do with you and me"
Nothing to do with my heart
Nothing to do with my head
Nothing to do with our home
Nothnig to do with our bed
It's just B I O L O G Y
Can't you see? It's just biology
Biology, coming in between you and me
Your biology lesson starts here
And first of all we should make it clear
That the species known as males
Have these little white things with little white tails
Which multiply and start to shout
It's getting crowded down here, let us out
Once relieved they start again
It's not a process controlled by the brain
It's nothing to do with their hearts
Nothing to do with their heads
Nothing to do with their home
Nothing to do with their beds
It's just B I O L O G Y
Can't you see? It's just biology
Biology, coming in between you and me
She said thanks, I'm so relieved
What your saying I can well believe
Now I know, I feel no shame
About Dave and Tony and Phil and James
I said, "Baby, baby, this can't be true
She said "Well what's right for you
Has to be right for me
In any case I'm sure you'll see"
It's nothing to do with our hearts
Nothing to do with our heads
Nothing to do with our home
Nothing to do with our bed
It's just B I O L O G Y
Can't you see? It's just biology
Why dont you fool me, feed me, say you need me without wicked games
Come on and hold me, hug me, say you love me, and not my dirty brain
Why don't you fool me, feed me, say you need me ,without wicked games
Come on and hold me, hug me, say you love me, and not my dirty brain
I got one Alabama return
that'll take me far away from you
cause when you take me in your arms I turn to slave but I cant be saved
So I got my cappuchino to go and I’m heading for the hills again
Cause if we party anymore we'll start a fire of pure desire
Closer ,your minds firing blind
With your head in your face getting red in your heart beats ,closer
you fall on your knees and the geek at your feet says your neat
and the beat gets closer
You dive for the thrill at the kill and your heart’s had its fill
But it still creeps closer
You wanted to freeze but your weak in too deep and the beat and the beat gets closer
Closer Closer Closer Closer Closer Closer Closer
We give it up and then they take it away
A girl’s got to zip it up
And get her head in the shade
Baby we give it up
Its just a matter of time
Throw all the heavy stuff
Comes back to bite your behind
You can’t mistake my Biology
The way that we talk
The way that we walk
its there in our thoughts
The magic number is in front of me
The way that we talk
The way that we walk
so easily caught
You can’t mistake my Biology
The way that we talk
The way that we walk
its there in our thoughts
We’re gonna cause a controversy
The way that we talk
The way that we walk
so easily caught
Why don't you fool me, feed me say, you need me without wicked games
Come on and hold me, hug me, say you love me, and not my dirty brain
Why don't you fool me, feed me, say you need me without wicked games
Come on and hold me, love me, say you love me, and not my dirty brain
You can’t mistake my Biology
The way that we talk
The way that we walk
its there in our thoughts
The magic number is in front of me
The way that we talk
The way that we walk
so easily caught
You can’t mistake my Biology
The way that we talk
The way that we walk
its there in our thoughts
We’re gonna cause a controversy
The way that we talk
The way that we walk
Im attracted anatomically
Need to know you scientifically
Strange confusion has come over me
Need the fusion between you and me
Mother Natures legislature, Mother Nature takes her course
Gravitation of the nation, Gravitation to the source
Im distracted biologically
My attention dominating me
Im a victim of Divine design
Im a victim of a one-track mind
Gut reaction, satisfaction, Gut reactions never lie
Need I mention my intention, Do I need an alibi
It happens every time you're next to me, Biology
Oh oh oh oh oh oh oh oh uh oh, BiologyIm defenseless, lacking all control
Its relentless, longing of my soul
I am driven, Im completely yours
Its a given, I'll be back for more
Its instinctive, so distinctive, and on that you may depend
Don't go mess with Mother Nature, shell defeat you in the end
It happens every time you're next to me, Biology
Oh oh oh oh oh oh oh oh uh oh, Biology
Need I mention my intention, Are you willing to supply
Gut reaction, Satisfaction, Gut reactions never lie
It happens every time you're next to me, Biology
It went like this, pistol Pete packed his bag and he split
He said "It's so hot and we might cave in"
So thanks for letting me crash back jump Justin
We struck again
And I'll be waiting up for no show Joe
Hanging with the smoked out savior
Seven taught me how to flow, we're on ill behavior,
You try to play it casual, let me know how far that gets you,
The bad seed Danny joins the navy eight,
And the workers always roll too late
You know that we'll be gone without a trace, not guilty
You try to play it casual, let me know how far that gets you,
You try to play it casual, I'm talking about the favoritism
It happens when you're in the loop,
And you'll be dancing to disintegration
And if the dean says that you're expelled
There is a desert in my mouth complete with tumbleweeds,
A billion grains of sand, cactus and coyotes,
There is a battlefield in my head complete with cannons and cavalry,
Helicopters overhead, and they're searching for yours truly,
Send me the bill for the mess we've made,
You survived the renaissance with souvenirs of powdered wigs and
Corsets for your cracked ribcage elegant figure,
Another living dead ballroom dancer shouting from escapes like
They've got the answer, come down and we'll converse, can you help
Me determine the measure of my worth, you know that our nightlife,
It runs into daylight,
We're the type of cats that bring an axe to a knife fight,
Its such a scene you second guess your vision,
I swear we're not dumb we just make bad decisions,
Will this discontent breed progression or insanity,
At least I'll have something to outlive my body,
Through the city we wonder like a dog without a collar,
I'm the same sword swallower, not much has changed,
Takers that vomits lines from dead philosophers,
But your vocab doesn't quite match your posture,
Through the city we wonder like dogs without collars,
I'm the same sword swallower, not much has changed,
And we won't be impressed by pseudo intellect,
We won't fall for that,
We won't carry paperbacks as props and never crack the cover,
We won't fall for that,
Contrived sophistication is a parasitic invasion,
When you've got no imagination, prosthetic humans,
Through the city we wonder like dogs without collars,
Old west, couch bound and reaching for the reset,
Sure bet, ten to win on "sorry's not an option",
We get paychecks to help support the habit,
In debt, it's all part of the process,
We hate when conversation gets the back seat
To the cold cold coldest shoulder and you're left in full retreat,
Hey room, I think we ought to separate pretty soon,
I've been stuck, it's like the way the waves depend upon the moon,
Shit luck, that's an excuse that we've been known to use,
Here is an inside joke but you're all on the outs,
And that's what we're about so don't try to get in,
All fresh at the controls, stretching out these bars,
So all your hips can move and shake with the dance part,
The quickest of fixes to nurse my needs, lets survey the options,
We all know opinions are like addictions, everyone's got one,
See me you just might go home and pick a fight
Then we can rack and write without any backlash,
Another inside joke and your still on the outs,
That's what we're about so don't try to get in,
Don't push me because I'm close to self destructing,
Lets hope all these come ups don't end too abruptly,
Getting over is a nightly ritual
I'd have to say we came a long way from the island,
It was a scene it was a drunken mess,
Now do you really miss what we left,
It may seem scripted like a movie,
How they pay me to sing about what moves me,
So we act the part and wait,
We wait for our big break,
A nervous gent abusive gem another trip to the Jave.,
The lines are hot exhale your lung with something we call the fresh new English tongue,
It may seem scripted like a movie,
But it drains me, the inconsistent jewel thief,
So we act the part and wait,
We wait for our big break,
You stepped on my tiny lines but I'll let it slide,
And their sorrows on display,
Please check your ego at the door
We gather to embrace our flaws, no corrections,
See I can write romantic songs,
But one on one I get it wrong, every time
Youth is a waste and wisdom comes too late,
An ambulance lights up the street,
So much for keeping it discreet, just deny
While spectators line the block
I have to be careful with what I say
I'm feeling dreadfully honest and I might give too much away
The truth is best kept secret when the secret will cause you pain
To confess it with some cliché lyric, well wouldn't that be such a waste
Show me something that is free from traps and drawbacks,
They've all got the sense of confusion,
But some more pronounced than they'd like to let known,
And the problem with living in general
You can make the effort and find your own direction
But if you lose anymore weight they are going to start asking questions
Maybe they're a shortage of ways to pass the time
You keep washing down those P.M.s with the blood of the vine
Now I've seen the logic behind your decision
It makes me feel remorseful like a born-again in prison
With a quick confession you start with a clean slate
If your gods that much of a push over then I guess you'll be OK
Show me something permanent and I will show you dissolution
I know that's sounding miserable but
Dear bad feelings, I'd say I'm through with you
Leave this body, go and find someone new,
Or retire, you've got no practical use,
We show up flawed at the perfection assembly,
Free handouts for the student bodies trembling
You can't teach a lesson on a subject that you've never experienced
And you can't just write off these nightmares likes it's a coincidence, it is not
With high fives, and back slaps, the stories they reenact,
Now tell me, and be exact, how bad you want your virginity back,
Disappointed treasure seekers dig a hold in your face,
You can live with my strangers and the gallery opening is never
Sure as the sun rises at dawn I thought that bird would always sing to me,
But this morning was a silent brick to the face dose of reality,
Not another album soaked with liquor and gimmicks
You see it streams from my grey matter and I just spit it
Like broken knuckles courtesy bar fight
This lethal spacecraft makes crash landings on the beach,
And our bodies dehydrate like earthworms in the summer heat,
Articulate reptilians pull the bodies from eroding shores,
Articulate reptilians won't wallow in the mud anymore,
Vanish we will, notice you won't, we'll pioneer the atmosphere,
Ambitious thoughts get put aside,
Street urchins with nowhere to hide,
Like arbitrary stimulation matters anyway,
When they're onto you, they're onto you,
They nursed us back to health with help from public slaves,
We danced all night and feasted on invertebrates,
Droves of civilians play into the plan,
It's a shame mediocrity is in demand,
With short-dime demeanor so clumsy my hands,
Hold on for one more phrase,
Lets be honest, be honest, this has got to stay off limits,
If we can't take these headaches that are bound to come with it,
Just say the word and I'll come to your coast,
I'll be the virus if you'll be the host,
Bore dumb defense for the absentee ghost,
Just slightly out of range,
It comes and goes but for the most part it's just not as bad as you once thought,