si una planta homocigotica de tallo alto (AA) se cruza con una homocigota de tallo enano (aa), sabiendo que el tallo es dominante sobre el tallo enano¡como seran los genotipos y fenotipos de la F1y de la F2.

it is called the mitotic spindle

to this answer it would be edge enhancement

the right option is; decreased genetic variation  

decreased genetic variation describes the effect of this environmental change.

genetic variation is the naturally occurring genetic diversities or differences between organisms of the same species in a population. genetic variation allows the survival and adaptability of a species when they encounter changing environmental conditions. when an endangered species reduces, it loses genetic variation which may not be restored even if the species rebound and will only be recovered through the gradual collection of mutations over many years.