Stem cells are the cells which has the ability to differentiate into different type of cells. As everyone know that human body loses and replaces a large number of cells daily the cells for replacement come from stem cells. Stem cells are generally of two types i) embryonic stem cells ii) Adult stem cells.
On the basis of potency stem cells are of 4 types
1) Totipotency ( totipotent stem cells) Totipotency means total potential. These are stem cells which have the ability to differentiate into any cell type including cells of extraembryonic tissues. Totipotent cells differentiate into pluripotent cells.
Example fertilized egg and zygote divided upto first 4 celled stage are totipotent cells.
2) Pluripotency ( Pluripotent stem cells) Pluri means many, which means these cells have potential to differentiate into many cells types but not all. These cells can differentiate into any cell types but not into cells of extraembryonic tissues. These cells can differentiate into three germ layer ecdoderm, mesoderm and endoderm.
Example Inner cell mass of Blastocyst stage of embryonic development can different into three germ layers.
3) Multipotent stem cells these cell type can differentiate into several cell types but can differentiate into limited cell types.
Example Hematopoietic stem cell ( a blood stem cell) is a Multipotent stem cell they can differentiate into all types of blood cells but cannot develop into brain cells.
4) Oligopotency (oligopotent stem cell ) These cells can differentiate into ony few cell types.
Example It includes lymphoid and myeloid cells formed from differentiation of Hematopoietic stem cells. lymphoid cell can give rise to B lymphocytess and T lymphocytes.
Sometimes unipotency term is also used. It includes cells which can differentiate into single type. Like hepatocytes which form cells of liver.
2. (a) Write down the definition of stem cell in your word. (b) Describe the four...
1. What is a stem cell line? A. Stem Cells lined up in a row. B. Stem Cells in the lineage. C. A population of Stem Cells grown by scientists. D. A Stem Cell broken down, with it's contents placed in a line. 2. What is an Adult Stem Cell? A. A cell extracted from mature tissue. B. A cell extracted only from children. C. A cell extracted only from adults. D. Both A and C. E. None of the...
2. Describe the first cell division in Dicot development (i.e., from a one-celled zygote to a two- veloping embryo). How do the two products of this cell division look? What are the two cells called and which parts of the embryo do their daughter cells give rise to?
Check Your Understanding 3.1 1 What are chromosomes made of? number 2 How many chromosomes are in a human somatic cell? 46 chromosomes 3 The term used to refer to this full complement of chromosomes is the 4 How many chromosomes are in human gametes? 5 This is referred to as the number 6 Wa chicken's skin cell has 78 chromosomes, how many chromosomes would the chicken's sperm cell have? 7 How can we distinguish the 23 types of chromosomes...
1. At the molecular level, what drives B cell development in the bone marrow? 2. What is the role of stromal cells in B cell development in the bone marrow? 3. Describe the sequence of events in B cell development with respect to rearrangement of heavy and light chain Ig genes. 4. Why does Ig gene rearrangement often fail to produce a functional protein product? What mechanisms exist to overcome this problem? 5. What is “allelic exclusion” and what is...
4. (a) Write down four nuclear reactions that describes decay of radioactive materials. Apart from these specific examples, write general equations for each of these four cases. (b) What are the ways to protect human lives against various radiation coming from radioactive decay processes? Do not use cursive writing. Write down the process in detail.
just question #2 Lymphocyte Development 1. B cell development in the bone marrow shares may features with T cell development in the thymus. A) Discuss what you consider to be the two major goals of lymphocyte development (i.e. what is the purpose of the Bone marrow and Thymus environments). B) Describe what occurs during the Precursor B cell stage and identify/describe the analogous stage in T cells. 2. With regards to what we've discussed regarding T cell development and alloreactivity,...
(17) (20pt) Let F be the set of functions f : R+ → R. Prove that the binary relation "f is 0(g)" on F is: (a) (4pt) Write down the definition for "f is O(g)". (b) (4pt) Prove that the relation is reflexive (c) (6pt) Prove that the relation is not symmetric. (d) (6pt) Prove that the relation is transitive. (17) (20pt) Let F be the set of functions f : R+ → R. Prove that the binary relation "f...
What benefit can human stem cells provide to individuals with a genetically determine immunodeficiency? How would the process work? Can individuals receive their own stem cells? Fill in the blanks with the missing information about primary and secondary lymphoid organs: The ___________ is the site of T cell development and maturation. The ________ is the site of B cell differentiation and hematopoesis. The ___________ are the sites where immune responses are mounted to antigens in the lymph. The _____________ is...
1. Describe the composition and function of cytoskeleton. 2. Define organelle. Write down the functions of each organelles of the animal cell. 3. Describe the phases of cell division (mitosis). 4. What is transcription and translation? What type of molecule results from transcription? 5. In what RNA molecules the codons and anticodons are found? What are start codons and stop codons ?
QUESTION 2 Copy of 1-3 Vocab Match the vocabulary word for each definition below A relational database chart that is used to map the infor-mation from the entity relationship diagram A. Nulls the unique identifier for each row of data B. Unique Links data in one table to the data in a second table by re-ferring to the PK column in the second table C. Table instance chart Indicates if a column must contain a value D. Foreign key (FK)...