Answer:
Explanation:
Muscle contraction is stimulated by the movement of an action potential moving along a nerve fiber to the muscles. This event follow some series of process before being stimulated.
1. The impulse arrives at the synapse and travels through the transverse tubules.
2. The muscle impulse reaches the sarcoplasmic reticulum and calcium is released.
3. Calcium floods the sarcoplasm and binds to troponin molecules leaving active sites.
4. Tropomyosin molecules bind to exposed active sites, linking actin and myosin.
5. Thin filaments are pulled over the thick filaments.
6. The muscle fiber shortens and contracts.
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.
Hii!!
The purpose of mitosis is to create two new perfectly identical cells when either there is a need to replace old or damaged cells and to reproduce asexually by making new cells. Some organisms use mitosis to replace body parts. For example starfish replace lost arms by mitosis. Some organisms such as the hydra use mitosis to produce genetically identical offspring.
There are four stages of mitosis: prophase, metaphase, anaphase and telophase.
1) Prophase: chromatin into chromosomes, the nuclear envelope break down, chromosomes attach to spindle fibres by their centromeres
2) Metaphase: chromosomes line up along the metaphase plate (centre of the cell)
3) Anaphase: sister chromatids are pulled to opposite poles of the cell
4) Telophase: nuclear envelope reforms, chromosomes unfold into chromatin, cytokinesis can begin
● The order of the stages of mitosis can be remembered using the mnemonic PMAT.
Hope this helps!! if it has pls mark me as the brainliest Xd :D
If you go on mc3.edu/admissions/applying-to-mccc/testing-and-assessment/assets/biology-placement-test.pdf page 11 it will tell you all the answers to your questions....
Answer: <u><em>D. An observation that has a number associated with it</em></u>
Explanation: The answer is D. An observation that has a number associated with it. I would explain further, but it is pretty self explanatory.
<em>Good luck!</em>
