What is the best explanation for the eradication of smallpox?

Where do homologous chromosomes exchange genetic material through crossing over?               a.  chlorophyll    b.  centrosomes    c.  centromeres    d.  chiasma

*will mark brainliest for first correct answer* which of the following is most likely to affect the biodiversity of a park ecosystem? a. less rain than usual for several months b. ongoing pollution from a nearby factory c. park rangers plant a new type of tree d. disease wipes out an entire population

Which of the following describes a boom period? a. as one population increases, another population decreases. b. as one population increases, the other population also increases. c. as one population decreases, another population increases. d. as one population decreases, another population also decreases