Answer:
Given:
Number of colonies on plate = 40
Amount of DNA used for transformation = 100ng
Volume of competent cells used = 100ul
Total volume = 1ml (1000ul)
Volume plated for growth = 200ul
The amount of cells transformed per 1 µg of DNA is called the transformation efficiency
(CFU is colony forming units) => (number of colonies on plate/ng of DNA plated) X 1000 ng/µg = CFU/µg of DNA
Amount of DNA used for plating = 100ng * (200/1000)
= 100ng * (1/5)
= 100/5 = 20ng
Efficiency calculation = 40 colonies / 20ng = 2 colonies/ng
(2 colonies/ng) * (1000 ng/µg) = 2000 CFU/ug DNA
Transformation efficiency = 2000 Transformants / ug DNA
= 2 x 10³ Transformants / ug DNA
Explanation:
Efficiency of transformation is highest in the 100 pg-1 ng range, so Low transformation efficiency could be because of high amount of DNA used for transformation.
Answer:
The answer to the question: Class II MHC proteins are found on which of the following cell types, would be: on macrophages and lymphocytes, particularly T-Cells.
Explanation:
MHC, or Major histocompatibility complex, is a very important part of the immune response that the body gives against an invading pathogen, or other foreign substances. There are three types in the human body, Class I, Class II and Class III and each of them will play a role on the cellular membrance of different types of cells and mediate different types of responses. In the human body, this histocompatibility complex is best known as HLA, or human leukocyte antigen, and it will ensure the recognition, or non-recognition of substances, tissues, and other organisms, by the human immune system. Class II, as mentioned before, are most usually found on the immune cells macrophages and lymphocytes, and they are the ones responsible for presenting antigens to these proteinic antibodies so that the immune cells can initiate a proper immune response.
Answer:do not use Gene invetro therapy with the RNA factor.It is looking like a crossthread on a bolt not able to unravel .
Explanation:
Answer:the possession of feathers
Explanation:birds are warm blooded animals , that possess feathers.these feathers cover their bodies and used for flight and warmth.their forelimbs are modified into wings,which fold into a Z shape at rest.feathers grow from the skin follicles and are replaced by scales on their legs.they possess oil gland to dress the feathers.
Other features of birds include
1) beaks with no teeth
2) fully ossified bones with air cavities
3)females with left ovary and oviducts only
Answer:
D.) repressor DNA-binding site mutation
Explanation:
lacl prevents the repressor polypeptide is a mutant that prevent operon from binding lactose, and thus will bind to the operator and be non-inducible.. This mutant will represses the lac operon whether lactose is present or not and the lac operon will not be expressed. It is also called“super-supperesor".
The lacI locus – One type of mutant allele of lacI (callled I-) prevents the production of a repressor polypeptide or produces a polypeptide that will not allow to bind to the operator sequence.
This is also a constitutive expresser of the lac operon because absence of repressor binding permits transcription.
