Laila
The complementary single-guide RNA (sgRNA) is artificially produced in a lab and acts as a template of the target DNA sequence. It will guide the Cas9 to cut the target DNA sequence. However for the Cas9 endonuclease to perform its function it needs to recognise the PAM sequence (very short sequence) adjacent to the target DNA sequence. The PAM sequence acts as a binding site for the Cas9 endonuclease. Once it binds it will perform its function of cutting the target DNA sequence. Have a look at the 2023 NHT Bio exam on CRISPR.

    Also I don't know if this is allowed to be asked, but anyone have any predictions for the VCE Bio exam questions this year aha.

    Is the proteome defined as all the proteins in an organism at a given point in time or is it defined as all the proteins made throughout the life of an individual?

      does anyone know if we need to know about reverse transcriptase and why is can't be used for some viirus testing in pcr?

      if we do can someone let me know the answer because i've tried searching on google but I can't find anything that relates to any other dot points.

        Taaaa76

        "Two reasons why RT-PCR cannot be used on all viruses included:
        • a suitable probe may not be available or a complementary probe has not been produced
        • not all viruses are made of RNA, or the nucleotide sequence in a virus may not be unique enough.
        Students who were able to apply their knowledge of complementary sequences to this unfamiliar situation provided suitable reasons."

        I get the second option, but I don't understand the first; do you know what suitable probe means?

          prettypink1881 The stem of that part of the question says the probes attach only to complementary sequences on particular viruses. So if a probe didn't exist with that particular complementary sequence then it wouldn't work because the probes are required for RT-PCR. I think?

            jessh24 i think divergent is, not convergent.

            All you would really need to know about convergent anyway is that analagous structures is a sign of it. Wouldnt hurt to know about it

            jessh24 No. In the biology FAQ document, it specifically states that knowledge of convergent and divergent evolution is not needed. You just need to know what homologous, analogous, and vestigial structures are (this is basically convergent and divergent evolution anyways). However, divergent evolution is basically just regular evolution, thus you may need to know it.

            Does anyone know if we need to know specific ways that scientists use CRISPR technology to modify organisms like non-homologus or homologous end joining?

              Meep<3 You do not need to know the specifics of NHEJ and HDR. You simply need to know that genes can be knocked in and out.