The gel should be placed in the correct direction so that the DNA bands can move.
- DNA is negatively charged due to the presence of phosphate groups, so it can only move towards the positively charged anode, otherwise, it will not move.
- So, when gel electrophoresis is done the side of the gel where the wells have been created and DNA samples have been loaded is placed at the side of the cathode, whereas the other side is connected to the anode.
- When the current flows, the DNA fragments also move from negatively charged cathode to positively charged anode as per their mass and size.
To know more about gel electrophoresis visit:
brainly.com/question/9437877
#SPJ4
Causes of speciation
<span>Geographic isolation
In the fruit fly example, some fruit fly larvae were washed up on an island, and speciation started because populations were prevented from interbreeding by geographic isolation. Scientists think that geographic isolation is a common way for the process of speciation to begin: rivers change course, mountains rise, continents drift, organisms migrate, and what was once a continuous population is divided into two or more smaller populations.
</span>Reduction of gene flow
<span>However, speciation might also happen in a population with no specific extrinsic barrier to gene flow. Imagine a situation in which a population extends over a broad geographic range, and mating throughout the population is not random. Individuals in the far west would have zero chance of mating with individuals in the far eastern end of the range. So we have reduced gene flow, but not total isolation. This may or may not be sufficient to cause speciation. Speciation would probably also require different selective pressures at opposite ends of the range, which would alter gene frequencies in groups at different ends of the range so much that they would not be able to mate if they were reunited.</span>
Answer:
The first human ancestors appeared between five million and seven million years ago, probably when some apelike creatures in Africa began to walk habitually on two legs. They were flaking crude stone tools by 2.5 million years ago. Then some of them spread from Africa into Asia and Europe after two million years ago.
It is called Acidosis or respiratory acidosis
Hope this helps
<span />
The name for the total amount of living matter is biomass. Hopefully this helps :)
