BIOL1006 Lecture Notes - Lecture 8: Acetabularia, Growth Medium, Cell Potency

14 views2 pages
25 Jun 2016
School
Department
Course
Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Lecture 8
Hammerling experiment - determined where cells kept hereditary
material
used Acetabularia cells, found that hereditary material in foot area
transplanted different parts of A. mediterranea and A. crenulata
parts eventually developed according to the hereditary material in foot
area (intermediate head formed at first due to remaining RNA left in
stalk)
transplantation experiments - added support that nucleus
contained hereditary material
Thomas King/Robert Briggs - transplanted nuclei from frog cells
cells wouldn’t develop w/o nucleus
showed that nuclei contained the information needed to direct
development
F. C. Steward - mixed fragments of carrot tissue w/ liquid growth
medium
showed that single cells can form entire, mature plants
totipotent - containing full set of hereditary instructions
Griffith experiment - discovered transformation
found that S. pneumoniae bacteria could only infect w/ polysaccharide
coating
dead bacteria w/ polysaccharide coating mixed w/ live bacteria w/o
polysaccharide coating to form live bacteria w/ polysaccharide coating
transformation - transfer of genetic material from one cell to another
Avery experiments - found the “transforming principle” from Griffith
’s experiments
removed nearly all of the protein in S. pneumoniae, but transformation
still occurred
purified mixture contained elements close to that of DNA, had same
density
taking out lipids/proteins didn’t stop transformation
DNA-digesting enzyme DNase stopped all transformations
showed that DNA provided hereditary material for bacteria
Hershey-Chase experiment - studied bacteriophages, viruses that
infect bacteria
viruses - contain DNA or RNA surrounded by protein coat
causes cells to produce so many viruses that it bursts (lyses)
used radioactive isotopes to track DNA and protein coat
showed that DNA caused changes in cells, not protein
nucleic acid - first discovered by Friedrich Miescher
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows half of the first page of the document.
Unlock all 2 pages and 3 million more documents.

Already have an account? Log in

Get access

Grade+
$10 USD/m
Billed $120 USD annually
Homework Help
Class Notes
Textbook Notes
40 Verified Answers
Study Guides
1 Booster Class
Class+
$8 USD/m
Billed $96 USD annually
Homework Help
Class Notes
Textbook Notes
30 Verified Answers
Study Guides
1 Booster Class