Answer:
I know it is jj. The answer is maybe that.
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....
Answer:
B) Natural selection favored rabbits that were resistant to the virus
Explanation:
Most likely, virus resistance occurred over time, as a consequence of mutation. Individuals that carried the resistance mutation become favourable by natural selection.
Natural selection is evolutionary mechanism which favours traits of an organism that help him survive and reproduce (increase organism's fitness). In the example above, resistant rabbits that survived had the favorable trait (resistance) by natural selection.
