https://padlet.com/jlsnowde/ghjqc4gl32jwvv78 Just click and type! The frog icon is in honor of MPF! en-us 2021-05-21 03:41:16 UTC 2026-01-08 07:25:46 UTC hello@padlet.com https://padlet.net/icons/png/1f438.png https://padlet.com/jlsnowde/ghjqc4gl32jwvv78/wish/1575047863 I am looking at the question in CC2 that is asking whether or not the cell labeling graph only applied to diploid cells vs. both haploid and diploid cells. I think I am missing a big piece of info, which is whether or not haploid cells go through the G1, S, G2, M cell cycle like diploid cells. My understanding of how haploid cells work is in the human context as a product of meiosis and 2 haploid cells coming together in fertilization. My guess is that the graph only applies to diploid cells (assuming that the haploid cells don't go through the cell cycle, but this is the point that I'm not sure of). On the other hand, relative DNA on the X axis makes me question things. My stumbling block here is lack of understanding of how haploid cells work.]]> 2021-06-01 03:21:07 UTC https://padlet.com/jlsnowde/ghjqc4gl32jwvv78/wish/1575047863 jlsnowde https://padlet.com/jlsnowde/ghjqc4gl32jwvv78/wish/1576408173 Haploid organisms exist. Many fungi, I believe all Saccharomyces  have haploid states. They actually have a lot of strange ploidy things, but relevant to the CC2 question is this passage in the free past edition of Molecular Biology of the Cell: https://www.ncbi.nlm.nih.gov/books/NBK26869/#A3173 

S. cerevisiae have haploid states with different mating types. Compatible mating types can fuse to form a diploid zygote. That diploid zygote is able to undergo meiosis to re-form haploid cells (now with some genetic variation on account of the process). 

]]> 2021-06-01 14:19:43 UTC https://padlet.com/jlsnowde/ghjqc4gl32jwvv78/wish/1576408173 https://padlet.com/jlsnowde/ghjqc4gl32jwvv78/wish/1577443670 The first part of the question says to "Write out the cell cycle and checkpoints for the G1/S transition that includes what is active during G1 and S phases." It also includes the specifics of what to add about the G1/S phases.
I have 2 questions:
1) So just to be sure, no need to go into other cyclin-CDK complexes other than the ones involved in the G1/S transition? (like the complexes in M)

2) In lecture 4, we learn that p16 inhibits CDK4/6 and that a Kip family proteins p21 and p27 inhibits cyclin E from binding CDK2. In Lecture 5 we only learn about p16 though. Is it necessary to include p21/p27 in the Q3 answer? Lecture 5 states that mitogens inhibit p16, but what inhibits p21 and p27? Also mitogens?
Thank you!]]> 2021-06-01 19:30:30 UTC https://padlet.com/jlsnowde/ghjqc4gl32jwvv78/wish/1577443670 https://padlet.com/jlsnowde/ghjqc4gl32jwvv78/wish/1577459049 When should we use RB vs. pRB?
Is pRB used for RB when hypo- or hyper-phosphorylated, and RB used only for naked, unphosphorylated RB?]]> 2021-06-01 19:37:07 UTC https://padlet.com/jlsnowde/ghjqc4gl32jwvv78/wish/1577459049 https://padlet.com/jlsnowde/ghjqc4gl32jwvv78/wish/1580942763 2021-06-02 23:25:23 UTC https://padlet.com/jlsnowde/ghjqc4gl32jwvv78/wish/1580942763