During what phase of mitosis does the nuclear envelope disappear and the chromosomes become distinct

Give three examples of plant activities that are affected by circadian rhythms and natural fluctuations in the length of daylight?

Which of these parts of the membrane large moecules pass through it ?

What does polymerase chain reaction (pcr) do? o a. separates dna fragments by size o b. cuts a dna sample into fragments o c. provides an overall picture of a person's chromosomes o d. makes more copies of a sample of dna