ELISA is highly sensitive and can detect antigen even in nanograms.
ELISA test does not require radio isotopes or radiation counting apparatus

(i) Stem cell banking is the extraction, processing and storage of stem cells, so that they may be used for treatment in the future, when required.
(ii) Amniotic cell bank is a facility that stores stem cells derived from amniotic fluid for future use.
(iii) Cord blood banking is the extraction of stem cells from the umbilical cord during childbirth.

1. Production of insulin by recombinant DNA technology started in the late 1970s.
2. This technique involved the insertion of human insulin gene on the plasmids of E. coli.
3. The polypeptide chains are synthesized as a precursor called pre-pro insulin, which contains A and B segments linked by a third chain (C) and preceded by a leader sequence.
4. The leader sequence is removed after translation and the C chain is excised, leaving the A and B polypeptide chains.
5. Insulin was the first eyer pharmaceutical product of recombinant DNA technology administered to human. In 1986 human insulin was marketed under the trade name humulin.

Dolly was the first mammal (Sheep) clone developed by Ian Wilmut and Campbell in 1997. Dolly, the transgenic clone was developed by the nuclear transfer technique and the phenomenon of totipotency. Totipotency refers to the potential of a cell to develop different cells, tissues, organs and finally an organism.
The mammary gland udder cells (somatic cells) from a donor sheep (ewe) were isolated and subjected to starvation for 5 days. The udder cells could not undergo normal growth cycle, entered a dormant stage and became totipotent. An ovum (egg cell) was taken from another sheep (ewe) and its nucleus was removed to form an enucleated ovum. The dormant mammary gland cell/udder cell and the enucleated ovum were fused. The outer membrane of the mammary cell was ruptured allowing the ovum to envelope the nucleus.
The fused cell was implanted into another ewe which served as a surrogate mother. Five months later dolly was born. Dolly was the first animal to be cloned from a differentiated somatic cell taken from an adult animal without the process of fertilization.

Advantages
1. Offers benefits for clinical traits and medical research.
2. It can help in the production of help in the production of proteins and drugs in the field of medicine.
3. Aids in stem cell research
4. Animal cloning could help to save endangered species.
Disadvantages
1. In animal and human activities, it as a threat to biodiversity saying that this alters evolution which will have an impact on populations and ecosystem.
2. The process is tedious and very expensive.
3. It can cause animals to suffer
4. Reports show that animal surrogates were manifesting adverse outcomes and cloned animals were affected with disease and have high mortality rate.
5. It might compromises human health through consumption of cloned animal meat.
6. Cloned animals age faster than normal animals and are less healthy than the parent organisms as discovered in Dolly.
7. Cloning can lead to occurrence of genetic disorders in animals.
8. More than 90% of cloning attempts fail to produce a viable offspring.

(i) Stem cells are undifferentiated cells found in most of the multicellular animals. 
(ii) These cells maintain their undifferentiated state even after undergoing repeated mitotic divisions.
(iii) Stem cells research has the potential to revolutionize the future of medicine with the ability to regenerate damaged and diseased organs.
(iv) Stem cell research has the potential to revolutionize the future of medicine with the ability to regenerate damaged and diseased organs.
(v) They are capable of self renewal and exhibit 'cellular potency'.
(vi) They can differentiate into all types of cells that are derived from any of the three germ layers ecto, endo and mesoderms.
(vii) In mammals there are two types of stem cells namely embryonic stem cells & adult stem cells (ES).
(viii) ES are pleuripotent and can produce the three primary germ layers ectoderm, Mesoderm and endoderm.
(ix) Embryonic stem cells are multipotent stem cells that can differentiate into a number of type of cells.
(x) ES cells are isolated from the epiblast tissue of the inner cell mass of a blastocyst.
(xi) When stimulated ES can develop into more than 200 cells Qpes of the adult body.
(xii) ES cells are immortal i.. e they can proliferate in a sterile culture medium and maintain their undifferentiated state.
(xiii) Adult stem cells are found in various tissues of children as well as adults.
(xiv) An adult stem cell or somatic stem cell can divide and create another cell similar to it.
(xv) Most of the adult stem cells are multipotent and can act as a repair system of the body and replenishing adult tissues.
(xvi) The red bone marrow is a rich source of adult stem cells.
(xvii) The most important and potential application of human stem cells is the generation of cells and tissues that could be used for cell based therapies.
(xviii) Human stem cells could be used to test new drugs.

Transgenic E.coli are also produced which produce milk included with human alpha lactalbumin.

A and R are true, R is not the correct explanation of A

Karl Ereky

intuferons

Cloning is the process of producing genetically identical individuals of an organisms either naturally or artificially. The first cloned organism is a sheep named Dolly.

(i) Clotting factor VIII isolated from blood of normal human being was used in the treatment of Haemophilia A.
(ii) Requirement of large quantities of blood for this purpose and the risk of transmission of infectious diseases like AIDS is a disadvantage.
(iii) Recombinant DNA technology was used to produce Recombinant Factor VIII in the Chinese Hamster ovary and in the baby Hamster kidney cells.
(iv) Recently a cell line of human origin has been used to produce Human blood, clotting factor VIII for the first time