Intro, Cells, Models (Lec. 1) Flashcards
Ch. 1 pg. 18-27
If you want to study the ways in which things move in and out of the nucleus, what experimental model would you use and why?
Yeasts are the simplest eukaryotes. They’re easy to keep, have a short life cycle (~2hrs), and a larger genome than E. coli but still smaller than humans. They have a distinct nucleus, their genomic DNA is organized into linear chromosomes, and they have organelles.
If you want to study DNA replication, gene expression, or protein synthesis, what experimental model would you likely use and why?
E. coli is easy to keep, has a short life cycle (~20 min) and a simple genome.
If you’re interested in studying development and differentiation in multicellular organisms, what experimental model would you use and why?
Nematodes like C. elegans are eukaryotic and multicellular, and they have a small number of genes and cells that have been mapped out. We can use mutations to study developmental abnormalities.
If you want to study the molecular mechanisms of development, what experimental model would you use and why?
Drosophila melanogaster (fruit fly) has a larger genome than C. elegans, is easy to maintain, and have a short reproductive cycle (~2 weeks).
If you want to identify genes involved in plant development, what experimental model would you use and why?
A. thaliana is a simple plant with a small genome that’s easy to grow and maintain, and methods for molecular genetic manipulations are available.
If you want to see vertebrate development in real time, what experimental model would you use?
Zebrafish are easy to maintain and reproduce rapidly (3-4 months). The embryos develop outside the mother and are transparent, and there are several molecular techniques available to map mutations.
If you want to study characteristics specific to mammals, what experimental model would you use?
Mice are more complex than other models. A lot of mice mutations have been identified, and mice with specific mutations are commercially available.
If you want to study signaling mechanisms in a cell, what experimental model would you use?
Cell cultures allow for controlled manipulations. The issue is that if you’re using a primary cell culture (sample taken directly from an organism), they won’t keep dividing forever. So it might be better to use an immortal cell line like HeLa cells.
Why are viruses useful as experimental models?
They’re obligate intracellular parasites, so they can be studied in cultured cells. They have relatively small and simple genomes, and it has been discovered that some cancers are caused by viruses.
Explain the advantages of E. coli for studying basic concepts of molecular biology
It’s relatively simple and can easily be propagated and studied in a lab.
Contrast yeast with E. coli as a model system
Yeast are eukaryotes. They’re more complex than E. coli but still far less than humans. They can be readily grown in a lab and can be used for a variety of genetic manipulations similar to those that can be performed using bacteria.
