The Cell Theory:
1. The cell is the smallest and most basic unit of life
2. Every cell comes from a pre-existing cell
3. Every organism is made up of one or more cells
1. The cell is the smallest and most basic unit of life
2. Every cell comes from a pre-existing cell
3. Every organism is made up of one or more cells
Limitations to the Cell Theory
•Striated muscle fibers: multi-nucleated, long (30 mm)
•Fungal hyphae: multi-nucleated
•Giant algae (Acetublaria): large (100 mm)
•Viruses: living or not?
•Striated muscle fibers: multi-nucleated, long (30 mm)
•Fungal hyphae: multi-nucleated
•Giant algae (Acetublaria): large (100 mm)
•Viruses: living or not?
Stem Cells:
Cells that retain capacity to divide and differentiate along different pathways, vital for embryonic development Multicellular organisms can differentiate into a variety of interdependent cell types
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Therapeutic Uses of Stem Cells and its Ethical Issues:
Thanks to today's advancements in technology, we hare able to dominate the use of stem cells. When a specific body part or organ is not capable of fulfilling its job, it affects our daily lives. But now we are able to regenerate that specific body part that it no longer working by extracting it from the stem cells. We can manipulate the stem cell and make it develop into the specific cell type that we want. This is a controversial topic because in order to obtain a stem cell one must get rid of the embryo. Stem cell opposers argue that a fully developed life can come from the embryo that is being killed, while the supporters argue that stem cell usage can put an end to the suffering (and large expense) of diseases and physical conditions. Another argument supporting the cause is that the embryos used are the left-overs of in-vitro fertilisation. In the near future, stem cells could be able to cure a wide range of diseases, like diabetes and heart-disease. http://www.explorestemcells.co.uk/stemcellcontroversy.html |
Beijing Puhua International Hospital:
A 52 year old man from Australia names John Clarke was diagnosed with Dilated Cardiomyopathy. He had shortness of breath and couldn't walk for more than 10 minutes. He couldn't dress himself or talk properly. His decease affected his daily life greatly. After stem cells were injected, his neural function and cerebral blood flow improved a lot. He was able to walk a kilometer before getting tired several times a day.
http://www.puhuahospital.com/?gclid=CILHp6viwcECFUsV7AodP1EAqw#!heart-disease/ch32
A 52 year old man from Australia names John Clarke was diagnosed with Dilated Cardiomyopathy. He had shortness of breath and couldn't walk for more than 10 minutes. He couldn't dress himself or talk properly. His decease affected his daily life greatly. After stem cells were injected, his neural function and cerebral blood flow improved a lot. He was able to walk a kilometer before getting tired several times a day.
http://www.puhuahospital.com/?gclid=CILHp6viwcECFUsV7AodP1EAqw#!heart-disease/ch32
Functions Necessary for Life
•Growth: an irreversible increase in size
•Homeostasis: keeping conditions inside the organisms within tolerable limits (temperature)
•Metabolism: chemical reactions inside the cell, including cell respiration to release energy
•Nutrition: obtaining food, to provide energy and the materials needed for growth
•Reproduction: producing offspring either sexually or asexually
•Sensitivity: perceiving and responding to changes in the environment
•Growth: an irreversible increase in size
•Homeostasis: keeping conditions inside the organisms within tolerable limits (temperature)
•Metabolism: chemical reactions inside the cell, including cell respiration to release energy
•Nutrition: obtaining food, to provide energy and the materials needed for growth
•Reproduction: producing offspring either sexually or asexually
•Sensitivity: perceiving and responding to changes in the environment
Metabolism and Cell Size
•Surface area determines rate of exchange
•Volume determines metabolism
Which is why with a large volume the cell will slow its metabolism. But with a high surface area the rate of exchange will increase compensating for the high metabolic demands
•Surface area determines rate of exchange
•Volume determines metabolism
Which is why with a large volume the cell will slow its metabolism. But with a high surface area the rate of exchange will increase compensating for the high metabolic demands
Microscopes
Microscopes have allowed us to learn mostly everything we know about cells. Light microscopes allow us to see a magnification of the cell through light. We can see their actual colour, but the magnification only allows us to see the general picture of the cell. In contrast, an electron microscope has a much greater magnification, and we are able to see all the organelles (and even chromosomes) inside the cell. It is monochromatic and uses electrons to show the image, it also has a better resolution
Magnification=measured length/scale bar label
Actual Size= measured length/magnification
Microscopes have allowed us to learn mostly everything we know about cells. Light microscopes allow us to see a magnification of the cell through light. We can see their actual colour, but the magnification only allows us to see the general picture of the cell. In contrast, an electron microscope has a much greater magnification, and we are able to see all the organelles (and even chromosomes) inside the cell. It is monochromatic and uses electrons to show the image, it also has a better resolution
Magnification=measured length/scale bar label
Actual Size= measured length/magnification
TOK: There is a difference between the living and the non-living environment. How are we able to know the difference?
We can tell the difference because of all the complex processes and systems that take place in a living environment. Non living environments do go through processes, but are different to the ones in the living environments.
We can tell the difference because of all the complex processes and systems that take place in a living environment. Non living environments do go through processes, but are different to the ones in the living environments.