Answer:
72F and 200ft
I believe this is correct
Crossing over is termed as a process by which genetic materials are exchanged by non-sister chromatids during meiosis.
Crossing over results in the new combination of information in genetic for, the cell for a specific trait.
It ensures that organisms are identical from one generation to another. Genetic recombination allows variations in genetic materials which are passed through generations.
For the first question is that crabgrass because in the process of secondary succession a forest fire burns down a forest then grasses grow back, then annual flowers bloom and eventually trees begin to grow so crabgrass is the initial stages of secondary succession.