What exchanges DNA during crossing over?

In what part of a chloroplast does glucose production occur? a. atp synthase b. photosystem ii c. photosystem d. stroma

The negative impacts of nonnative species generally outweigh the positive impacts

What molecules will be best used to compare different species with the exact same sequence of amino acids? why would two species have the same protein even if the molecules in question is different? (hint: transcription to translation to protein).