LacOperon
where do you find a LacOperon and what type of cell is it
E.Coli and prokaryote
what is a CpG site and where are they located
CpG sites are cytosine's located near guanine's in a DNA sequence, typically found near a promoter
when is CDK active
when cyclin is bound to it
list the 5 stages of mitosis in order
prophase, prometaphase, metaphase, anaphase. telophase
when is haploid status achieved
after the 1st round of meiotic division
what is positive regulation in the LacOperon (must describe what is present and what happens)
when lactose is present and represses the repressor keeping it from binding to LacO, therefor RNA polymerase will bind and transcribe genes
list 3 DNA sequences involved in transcription positive/negative regulation and the 3 types of proteins that would bind to them (eukaryotes)?
1. promoter: General TF's
2. Enhancers: Activators
3. Silencers: Repressors
list the 3 cell cycle checkpoints and where they occur
dna damage: G1
dan replication: G2
spindle assembly: M phase (prophase)
what is the end result of mitosis
2 genetically identical diploid cells
what is the end result of meiosis
4 genetically unique haploid cells
this gene codes for a enzyme that breaks down lactose into glucose and galactose (say the gene and enzyme)
Lac-Z codes for B-galactosidase
define combinatorial control
Whether and how much the gene is transcribed in a particular cell depends on the exact combination of TFs that are present, and thus bound to their respective regulatory regions for that gene, in that cell
draw out DNA replication be sure to include the following: topoisomerase, helicase, rna primer, DNA polymerase, single stranded binding proteins, directionality (5 and 3 ends), leading strand, lagging strand
I will judge
what happens in anaphase (be specific)
the sister chromatids are separated and pulled to each side of the cell by spindle microtubules
state the phases in which cells increase genetic variation in meiosis and how they increase diversity
prophase 1: crossing over between maternal and paternal homologs randomly
metaphase 1: random orientation of homologous chromosomes
metaphase 2: random orientation of chromosomes
List at least 2 mutations in which a LacOperon would always transcribe its genes (must be able to justify reasoning)
1. The lacI produces a protein that degrades quickly
2. LacO has a mutation where it can't bind to anything
What are the 2 ways to regulate transcription through epigenetics and what would the effect of these be
1. Acetylation of histone tails: more transcription because more open chromatic
2. Methylation of CpG sites: less transcription because chromatin is condensed
what happens when p53 doesn't degrade in a cell (damage checkpoint)
it will positively regulate the expression of BAX, encodes a protein (Bax) that causes apoptosis
what marks the beginning of cytokinesis
the formation of the contractile ring
Using terms like homologous and replicated and sister chromatids answer the following:
During G1 phase what type of chromosomes do you have...
During G2 phase what type of chromosomes do you have...
At the end of Meiosis 1 what type of chromosomes do you have...
At the end of meiosis 2 shat type of chromosomes do you have....
G1: You have unreplicated homologous chromosomes
G2: you have replicated homologous composed of sister chromatids
meiosis 1: homologous chromosomes are separated but they are still in their replicated form
meiosis 2: sister chromatids are separated no longer in their replicated form
A mutation occurs in the E. coli lac operon that prevents the repressor protein from binding to the operator region. The bacterial cells are then grown in an environment with no lactose present. Based on what you know about how the lac operon functions, predict what will happen to the expression of the lac genes and explain why this could be disadvantageous for the cell.
The lac genes will be continuously expressed, wasting energy by producing enzymes that aren’t needed.
Both the stomach and the brain contain the same gene, CDG530, which codes for an acid-producing enzyme. Based on what you’ve learned about gene regulation, explain why this gene is actively expressed in stomach cells but not in brain cells. (Not epigenetic)
your stomach has the correct TF's to activate the enhancers and promoter associated with the gene in the stomach whereas the brain does not have these
what purpose does the phosphorylated target protein serve from the cyclin-CDK complex (ill accept any of the 4 answers)
Chromosomal proteins that initiate M phase, Proteins that break down nuclear envelope, Microtubule-associated proteins to activate mitotic spindle, Enzyme that degrades cyclin; cyclin concentrations decline
A scientist observes a cell under a microscope and notices that the chromosomes are aligned in the center of the cell, but the spindle fibers from opposite poles are not properly attached to all centromeres. Predict what could happen to the daughter cells if this problem is not corrected before the cell divides and also state which phase is being affected
One daughter cell may receive extra chromosomes while the other may be missing some, Anaphase
Scientists are working to create a mutation that would allow for humans to produce humans with more DNA content, they are aiming to disrupt the separation of sister chromatids, which phase should they try to target and whats one way you can think of they could disrupt this separation
anaphase, they could disrupt the spindle microtubules ability to pull chromatids apart but only in meiosis 2