The stage of meiosis in which chromosomes pair and cross over is: a. prophase i b. metaphase i c. prophase ii d. metaphase ii e. anaphase ii

The answer here is Prophase 1 (A)

In the event of meiosis, Prophase 1 occurs right after Interphase (stage when DNA is replicated). In the Prophase 1 stage, chromosomes condense and pair off and then exchange DNA between each other in a manner of crossing-over homologous chromosomes.  The cross-over procedure forms a X-like region called Chiasmata that holds the homologous chromosomes intact.

The answer is atmosphere. there are four spheres of the earth: 1. geosphere (from greek word 'geo' = ground), 2. hydrosphere (from greek word 'hydro' = water), 3. biosphere (from greek word 'bio' = life), and 4. atmosphere (from greek word 'atmo' = air). a magnetosphere is a region of space around astronomical objects controlled by the magnetic field of that object. through the process of elimination, since lightning is present in the air, it can be found in the atmosphere.

Ecological footprint is determined by measuring carbon dioxide emissions for a given region.