you should know for exam 2 Flashcards
how does an embryo develop axes
via expression of specific sets of genes that regulate which cells will develop into specific structures.
how is gene regulation responsible for cell differentiation
regulated by transcription factors and growth factors, results in expression of various genes between the cell types, thereby resulting in varying proteomes between cell types
role of hox genes in animal developmemt
This cluster of genes is responsible for determining the general body plan, such as the number of body segments of an animal, the number and placement of appendages, and animal head-tail directionality.
compare gene regulatory systems of bacteria and eukaryotes
In summary, gene expression in bacteria via the operon system is more simple and efficient and does not require coordination across different segments of DNA and as many moving parts (transcription factors, cell signals) as eukaryotes. This allows bacteria to rapidly respond to changing environmental conditions which is advantageous.
Explain the additional challenges to gene regulation that must be met in eukaryotes.
In eukaryotes, control of gene expression is more complex and can happen at many different levels. Eukaryotic genes are not organized into operons, so each gene must be regulated independently. In addition, eukaryotic cells have many more genes than prokaryotic cells.
Explain how chromatin modification regulates gene expression
The chromatin modifications that we just discussed do not change the DNA sequence, yet they still may be passed along to future generations of cells. Before a gene can be expressed, it is necessary to first create accessible sites for the binding of transcription factors required for transcription initiation and secondly, to modify the histones within nucleosomes and reorganize the higher order chromatin structure to create an environment permissive for the passage of RNA-polymerases.
Explain how transcription regulation regulates gene expression
Groups of transcription factor binding sites called enhancers and silencers can turn a gene on/off in specific parts of the body. Transcription factors allow cells to perform logic operations and combine different sources of information to “decide” whether to express a gene.
explain why gene regulation is important
Describe how DNA-binding proteins bind to specific nucleotide sequences
Describe how bacteria regulate gene expression
Describe an operon and its components
Contrast inducible and repressible operons
How is the genetic material exchanged during a crossover in prophase I?
Describe the phases of Meiosis and how genetic material is exchanged during prophase I
Contrast Meiosis and Mitosis
