Chapter 8.7 Flashcards
STEM CELL
is any undifferentiated cell that can give rise to specialized cell types.
SPECIALIZED CELLS
permanently differentiated cells. Although all cells contain the same DNA, in specialized cells some genes become irreversibly “turned off”. Once in this state it is irreversible.
What occurs when stem cells divide mitotically
First, each yields 2 daughter cells: One remains a stem cell, able to divide again–the other specializes
The categories of Stem Cells in animals
- EMBRYONIC
2. ADULT
EMBRYONIC STEM CELLS
give rise to all cell types in the body, including adult stem cells, and are therefore called “ TOTIPOTENT” ( entire)
ADULT STEM CELLS
are more differentiated and produce a limited subset of cell types
They are “ PLURIPOTENT” “ many”
They give rise to only one sell type
egs of ADULT STEM CELLS
Stem cells in the skin replace damaged skin cells.
2. stem cells in the bone marrow produce all of the cell types that make up blood
Where are human embryonic stem cells derived from
The inner cell mass of a blastocyst: The inner cells yields embryonic stem cells that have the ability to form any cell type in the body.
A BLASTOCYSTS
is a human cell 5 days after fertilization
“induced Pluripotent stem cells
are adult stem cells that had some of its gene expressions manipulated so that it acts like a embryonic stem cells
SOMATIC CELL NUCLEAR TRANSFER
A technique of cloning.
. the nucleus of a donor somatic cells is transferred to a enucleated( nucleus was removed) egg cell.
. The resulting cell divides mitotically to form an embryo, which is implanted in a surrogate mother’s uterus. ( REPRODUCTIVE CLONING)
. Mitotic cell division then would produce every cell in the clones body.
Why was the dolly cloning significant
because it showed that the DNA from a differentiated somatic cell( adult cell) could revert to a undifferentiated state.
What was the suspected cause of Dolly early death
the already shortened telomeres that she inherited from the 6 year old donor nucleus
Therapeutic cloning
cloned human embryos are used as a source of stem cells which could be used to grow customized artificial organs that the patient’s immune system would not be rejected
Describe the differences between embryonic, adult, and induced pluripotent stem cells
Embryonic stem cells are totipotent and give rise to any cell in the body. Adult stem cells are pluripotent, with the ability to become most (but not all) cell types.. Induced pluripotent stem cells are adult stem cells that have gene expression manipulated in such a way that they become like embryonic stem cells.
What are the potential medical benefits of stem cells
Stem cells help illustrate how animals develop and grow; they may be useful in treating diseases that involve tissue loss or damage, also they are useful in observing the development of a disease from its start. Finally, stem cells may also be useful in drug testing.
Why is the cloning technique called somatic cell nuclear transfer
The nucleus of a somatic body cell is used rather than the nucleus of a sex cell.
Summarize the steps scientists use to clone an adult mammal
Cells from the animal to be cloned are grown in culture, and then the nucleus of one of those cells is removed. That nucleus is then fused with a denucleated cell from an egg donor. The fused cell is allowed to divide into an embryo and is then implanted into the surrogate where it is allowed to develop to birth.
