The second and fourth answer. :)
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.
The answer would be letter C
As the days get shorter and the temperature drops, this bear overeats and stores food as fat to get ready for hibernation.
When hibernate, bears will keep sleeping so they won't get any food from outside so they need to collect the food before hibernating. They have to eat more food than usual and stored it as fat to keep them from starving. The fats also help keep them warm as they are insulating the heat.
It is either carcinogens or viruses (I think the first) I hope this helps!
