Question

question 31
when dna is copied to make more dna before cell division, what happens to the original dna molecule?
a the original dna goes to one cell; the new dna goes to the other cell.
b only new dna is passed on; original dna is broken down and recycled.
c each of the cells contains half of the original dna and half new dna.
d the original dna is twisted into a double helix and passed to one of the daughter cells.
e either a or c are true, depending on the organism.
question 32
what is the correct sequence in creating a dna profile?
a collect sample->extract dna->pcr to amplify strs->gel electrophoresis->analyze gel
b collect sample->extract dna-> gel electrophoresis->pcr to amplify strs-> analyze gel
c collect sample->gel electrophoresis->extract dna->pcr to amplify strs->gel electrophoresis again->analyze gel
d collect sample->pcr to amplify sample->gel electrophoresis->extract dna->gel electrophoresis again->analyze gel
e pcr to amplify sample->extract dna->gel electrophoresis->analyze gel

Explanation:

For Question 31, DNA replication follows a semi - conservative model. Each new DNA molecule consists of one original strand and one newly synthesized strand, so each cell gets half original and half new DNA. For Question 32, the standard process of creating a DNA profile starts with sample collection, then DNA extraction, followed by PCR to amplify short tandem repeats (STRs), then gel electrophoresis to separate the DNA fragments, and finally analyzing the gel.

Answer:

Question 31: C. Each of the cells contains half of the original DNA and half new DNA.
Question 32: A. Collect sample->extract DNA->PCR to amplify STRs->gel electrophoresis->analyze gel