Crossing over happens in Meiosis 1 only. In Prophase 1 a cells chromatin (chromatin = chromosomes that have not condensed yet) condense and pair up forming homologous chromosomes (paired = XX (2 chromosomes together)). When this happens segments/ alleles of the chromosomes pairing up swap over. This creates genetic diversity as each chromosome is different, it has parts from its pair. This leaves every chromosome unique and individual.
I hope this helps, sorry some of the vocab is rather technical. By the way I would suggest watching the
'Crash Course: Meiosis' on YouTube, this really helped me when I was learning this topic. :D
The second diagram best represents regeneration
Genetic information.The main job of DNA is to carry the code for making protein.A gene is a stretch of DNA that can be read by proteins called ribosomes, and copied I to type of nucleic acid called massenger RNA.
Struggled with this earlier but because of the high altitude only some animals can live there and thrive because of the lower oxygen levels