Which is the most likely reason that stem cell research is controversial?
-stem cell research could lead to the development of human clones
-many people assume that all human stem cells come from embryos.
-research by using stem cells results in high-priced treatments for disease.
-information that is obtained from stem cell research is considered unreliable.
Basically, many people assume that all human stem cells come from embryos.
A. Adult stem cells have unipotency, and embryonic stem cells have pluripotency.
The basic difference between a stem cell and a totipotent cell is that a stem cell has the potential to regenerate itself apart from producing other cells which are alike, for example hematopoietic stem cell. In contrast to this, a totipotent cell has the potential to develop into an entire organism but it cannot regenerate itself, for example zygote. Zygote can produce the entire organism but once zygote divides to form an embryo it can never become a zygote again.
In the early embryonic stages in mammals when the zygote divides to form 8 celled morula, each of the cell of morula retain its power of regeneration of an entire individual if allowed to develop separately but with advancement in development, the stem cells start to loose their potential to develop into the entire individual and they are confined to only pluripotency which means that they can only form an embryo and some parts of extra embryonic membranes not all of them.
Further when gastrula stage arrives, the power of cells to regenerate reduces even more and become restricted to only multipotency.
In the end, when the entire individual is developed the adult stem cells remain the only cells which have power of regeneration and they have unipotency which means that they can regenerate only one type of tissue. For example, skin cells are unipotent cells which can only regenerate skin.
Adult stem cells have unipotency, and embryonic stem cells have pluripotency.
Although we do know that stem cell research is very controversial, but one cannot deny the fact that by far it is most effective technique for treating those diseases whose cure is otherwise impossible.
Regenerative medicines and therapeutic cloning are very effective to control many dreadful diseases.
By studying stem cells, scientists can study how to treat an ailment whose cure was otherwise unknown. As diseases like cancer occur due to inappropriate divisions, study of stem cells enable scientists to learn the mechanism of differentiation and how it gives rise to cancer.
One of the methods through which stem cells can be obtained is the method of induced pluripotency. By this method, pluripotent stem cells can be made from adult stem cells.
Adult stem cells can only differentiate to form a single type of cell.
Embryonic stem cell are pluripotent as they can differentiate into any cell types except extra embryonic membranes like placenta.
Only zygotic stem cells are totipotent
D. Embryonic stem cells have longer telomeres and persist for much longer than adult stem cells
Embryonic stem cells may become any type of cell, whereas adult stem cells may only become a limited number of cell types.
Im not sure I haven't ever understood this clearly
answer: collecting information/data
reason: the student is going around and asking people questions to collect data
i hope this
events in order:
1. vishnu schist
2. zoroaster granite
3. bass limestone
4. hakatar shale
5. igneous intrusion
6. shinumo quartzite
7. dox sandstone
8. tapeats limestone
9. bright angel shale
10. muav limestone
11. temple butte limestone
12. redwall limestone
answer: the unkar group shows angular unconformity because the layers are turned at angle.
answer: specifically the angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled. an angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled.
answer: the disconformities aremarked irregular lines between the sedimentaryrocks layers.
-stem cell research...