## Part one: Q and A Active Recall Flashcards
## Part one: Q and A Active Recall Flashcards
### Section ten point one: Applications in Agriculture
** Question: ** What are the three critical research areas of biotechnology?
* ** Answer :** One. Providing the best catalyst in the form of an improved organism (microbe or pure enzyme).
Two. Creating optimal conditions through engineering for the catalyst to act.
Three. Downstream processing technologies to purify the protein or organic compound. ** Question: ** What is totipotency? * ** Answer :** The capacity to generate a whole plant from any single cell or explant. * *Question: ** How can you obtain a virus-free plant from a diseased, virus-infected plant? * ** Answer :** By removing the meristem (apical and axillary), which remains free of the virus, and culturing it in vitro. * ** Question: ** What is a somatic hybrid? Give an example. *
* ** Answer :** A hybrid plant formed by fusing naked protoplasts (isolated single cells with digested cell walls) from two different plant varieties. An example is the "pomato" (tomato plus potato hybrid).
* ** Question: ** Why does Bt toxin not kill the Bacillus thuringiensis bacterium itself? * ** Answer :** The Bt toxin protein exists as an inactive protoxin within the bacterium. It only converts into its active toxic form due to the alkaline pH of an insect's gut, which solubilizes the crystals.
* *Question :** How does active Bt toxin mechanically kill an insect?
* ** Answer :** The activated toxin binds to the surface of the insect's midgut epithelial cells, creating pores. This causes cell swelling, lysis, and eventually leads to the death of the insect.
* ** Question: ** Which specific cry genes control cotton bollworms, and which one controls the corn borer?
* *Answer: ** * Cotton bollworms: ** Controlled by genes cryIAc and cryIIAb.
*Corn borer: ** Controlled by the gene cryIAb.
Question :** Explain the mechanism of RNA interference (RNAi) used in pest-resistant *
tobacco plants. * ** Answer :** RNAi involves silencing a specific mRNA. Nematode-specific genes are introduced into the host plant using Agrobacterium vectors, producing both sense and anti-sense RNA. These complementary strands form double-stranded RNA, which binds to and initiates the silencing of the nematode's specific mRNA, preventing its translation and survival.
### Section ten point two: Applications in Medicine
### Section ten point two: Applications in Medicine
* ** Question: ** Why do recombinant therapeutics have an advantage over products isolated from non-human animal sources? * ** Answer :** They do not induce unwanted immunological responses (like allergies or foreign protein reactions) because they are identical to human proteins.
* *Question :** What is the structural difference between proinsulin and mature functional insulin?
** Answer :** Proinsulin contains an extra stretch of amino acids called the C
peptide. This C peptide is completely removed during the maturation process and is not present in mature insulin. * *Question :** How did the American company Eli Lilly successfully produce human insulin using rDNA technology in nineteen eighty-three? * ** Answer :** They prepared two distinct DNA sequences corresponding to the A and B polypeptide chains of human insulin. They introduced them separately into the plasmids of E. coli to produce the chains individually, extracted them, and combined them by creating disulfide bridges. * ** Question: ** What was the cause of the genetic disorder treated in the first clinical gene therapy (nineteen ninety), and how was it done? * ** Answer: ** It was caused by the deletion of the gene for adenosine deaminase, an enzyme crucial for the immune system. Lymphocytes from the patient's blood were grown outside the body, a functional ADA CDNA was introduced into them using a retroviral vector, and the engineered cells were returned to the patient.
* ** Question: ** Why is the current lymphocyte-based gene therapy for ADA deficiency not a permanent cure, and what would be? * ** Answer :** Lymphocytes are not immortal, so the patient requires periodic infusions of engineered cells. A permanent cure would involve introducing the ADA-producing gene isolated from marrow cells into cells at early embryonic stages.
* ** Question: ** Name three techniques that allow for the early molecular diagnosis of diseases before symptoms appear.
** Answer: ** One. Recombinant DNA technology.
Two. Polymerase Chain Reaction.
Three. Enzyme-Linked Immuno-sorbent Assay.