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:
because they dont need to consume energy to survive and they have to take control of a host cell to reprouce/replicate, they cant do it on their own
Explanation:
hope this helpedd :)
<span>There are no choices given, but the event was most likely a physical one that would have barred the squirrels from seeing each other. Squirrels are a social creature, and the event that would have separated the populace could have been anything from a large fire to an earthquake that separated the squirrels from each other.</span>
Answer:
the element oxygen , represented by the symbol o, is classified as a pure substance
The answer would be the last one because a deletion changes every codon configuration that follows it and thus changes the amino acid that codes for that codon