Answer:
Smaller the size of the DNA fragment, farther it moves during electrophoresis. The sketch of the position of the fragments has been drawn in the figure below.
Explanation:
As we know DNA is a negatively charged molecule. So during electrophoresis the fragments move towards the positive electrode because opposite charges attract each other.
Different fragment move different distances according to their size during the electrophoresis. Smallest segment travels the largest distance in the gel medium while the largest one travels least distance.
In the question there are four DNA fragments with base pairs 4000, 2500, 2000 and 400 so the smallest segment with 400bp will be farthest from the starting point and the largest fragment with 4000bp will travel least distance in the gel medium. Their respective positions are shown in the figure below. The starting point is near the negative electrode.
Answer:
Akira turns in a written lab report to his science teacher. ... Akira writes in his notes that adding a catalyst sped up the chemical reaction because the catalyst lowered the activation energy needed to start the reaction.
........... the membrane potential will become more POSITIVE.
A membrane become depolarize when sodium enters the neuron via chemically gated sodium channels, this means that, the membrane become more positive when sodium ions diffuse into the cells.<span />
Considering the following;
I. Heat is not readily available to all living cells.
II. Heat at excessive amounts denatures proteins.
III. Heat does not provide the activation energy for their reactions.
IV. When a critical temperature is reached, proteins no longer function
Answer;
I and IV
Explanation;
Living cells cannot use heat to provide the activation energy for biochemical reactions because heat is not readily available to all living cells and also when a critical temperature is reached, proteins no longer function.
Too much heat can kill an organism by rendering its organelles, cells, tissues and organs permanently inoperable and un-salvageable. The same process can be observed in tissues at low temperatures, and is the cause of frostbite. This is because enzymes are denatured by high temperature and inactivated by low.
