2. Cell division, differentiation, and morphogenesis?
3. What controls differentiation and morphogenesis?
1. An operon consist of 3 parts. operator, promoter, and the genes of the operon. Operator controls the access of rna polymerase to the genes, it is found within the promoter site or between the promoter and the protein coding genes of the operon. promoter is a place where rna polymerase attaches. the genes of the operon is the entire strecth of dna required for all the enzymes produced by the operon.
2. cell divison is the series of mitotic divisions that increases the number of cells. cell differentiation is the process by which cells become specialized in structure and function. morphogenesis is the organization of cells into tissues and organs.
3. cytoplasmic determinants are maternal substances in the egg that influence the course of early development. these are distributed unevenly in the early cells of the embryo and result in different effects. cell-cell signals result from molecules, such as growth factors, produced by one cell influencing neighboring cells, a process called induction which causes cells to differentiate.
video on cell division:
image of an operon:
5 main facts on this chapter:
. Differentiation is heralded by the appearance of tissue-specific proteins, which enable differentiated cells to carry out ther specialized roles.
. Normal cells are converted to cancer cells by the accumulation of nutations affecting proto-oncogenes and tumor suppressor genes.
. Some operons are also subject to positive control via stimulatory protein, such as catabolite activator protein CAP, shich promotes transcription when bound to a site within the promoter.
. The expression of eukaryotic genes can be turned off and on at any point along the pathway from gene to functional protein.
. Determination is the series of events that lead to observable differentiation the a cell.
In this chaper, we learned the functions og the three parts if an operon,the role of repressor genes in operons, the impact of DNA methylation and histone acetylation on gene expression, and the role of oncogenes, proto-oncogenes, and tumor suppressor genes in cancer.
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