Answer:
Less biological relevant model and reduce cell to cell interaction.
Explanation:
The two main disadvantages of a 2D model of the digestive system is that it is less biological relevant model and reduce cell to cell interaction. The 2D model does not show high resemblance to reality and this model also fail to show the interactions of two cell surfaces with each other. In short, this model, does not give us complete knowledge about any biological system.
Answer:
1) Stem cells can renew themselves by dividing into more stem cells more than once.
2) There are two types of stem cells: adult and embryonic stem cells.
3) Stem cells are not specific to one area in the body and can turn into skin, bone, blood or brain cells.
It was developed by Alfred Wegener around 1912-1915 time frame. He proposed his theory of the "continental drift". He proposed that the continents plowed through crust of ocean basins. He said that the continents look like a puzzle piece to put together. It's very interesting.
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