During metaphase, chromosomes that are attached to microtubules are observed to undergo a "back-and-forth" movement. What is happening during this movement?
the chromosomes are being replicated
the centrosome is being replicated
the chromosomes are breaking up the nuclear membrane
the chromosomes are being aligned at the equator of the cell
the contractile ring is forming
2007-05-31 09:47:05 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Biology
They are being aligned at the equator
2007-05-31 09:57:51 · answer #1 · answered by hcbiochem 7 · 0⤊ 0⤋
Micro-evolution is defined as the change of allele frequencies within a population over time and can include speciation within the kind. Even a mutation creating a new allele falls within this definition since the organism remains in the same kind. Macro-evolution requires the formation of new genetic information and changes beyond the boundaries of the kind. If you are after Creationist justification for these definitions it is that God created all things to reproduce after their kind. Even Linnaeus recognised that kind did not correspond exactly with his taxonomic divisions. Yes I have looked at the TO list of speciation and they are all within the existing kind and are examples of micro-evolution. Biologists have trouble precisely defining species and creationists have trouble determining the boundaries of kind. That doesn't make either concept unusable. Evolutionists are also adept at changing the definitions of their terms (such as vestigial) so Creationists need not apologise for refining their definitions where necessary as biological knowledge improves.
2016-04-01 07:36:56 · answer #2 · answered by Anonymous · 0⤊ 0⤋