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
Answer:
The ecosystem would be forced to radically change, allowing new and possibly invasive species to populate the habitat.
Explanation:
A keystone species is an organism that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether.
I HoPe ThIs HeLpS!!!!!
Answer:
An open system is a system that has external interactions. Such interactions can take the form of information, energy, or material transfers into or out of the system boundary, depending on the discipline which defines the concept
Explanation:
Several things; don't use multiple patches, never take an ED medication (Erectile Dysfunction), if sign and symptoms including those of hypotensive reading, go to the emergency room.
Could cause loss of animal habitats or more animals can become extinct because the more we built the more we are pushing them from there homes.