Its A and B i think because when cold air and warm air.mixed it.form precipitation like tornado
For question 3, it would not leak through the whole sandwich because the cell membrane is thick
One type of density change is mass over volume.
Answer:
I think you're referring to the Metaphase...
Explanation:
During Cell Division (or, rather before!) the DNA needs to be replicated. This normally is done by DNA Polymerase, and results in two identical double strands (the "Sister Chromatids".
These chromatids are held together at the Centromere, which will be the heart of the "X"-shape. After that the DNA is packed into Chromosomes by winding it around proteins called Histones. If I remember correctly there are 5 different Histones.
This "Zipping Up" makes the chromosomes more visible.
As the two sister chromatids are still connected, the result is the X-shaped Metaphase Chromosome....
Geologist Alfred Wegner noticed similar rocks & fossils remains were found on Continents which seemed to fit together. He called saw that it was the result of Continental drift and Pangea. Some evidence of the Drift was Rock evidence- Mountain ranges, Glacial scares, Location of coal deposits, ETC..
People couldn't image how the Earth could be millions of years ago. But the 1960's evidence would prove Continental Drift is TRUE and .. the story continues (as all good science!)
Continental drift means that continents move away from each other or separated.
