exam 3 - inheritance and DNA as genetic material

chromosomal disorders

ofter occurs during nondisjunction

nondisjunction

failure of chromosomes or sister chromatids to separate properly during cell division

euploidy

appropriate number of chromosomes (22 pairs autosomes, 1 pair sex)

aneuploidy

abnormal chromosome number

monosomy

losing one chromosome

trisomy

gaining an extra chromosome

polyploidy

>2 sets of chromosomes; common in plants, rare in animals

chromosomal inversion

mutation where a segment of a chromosome breaks off, flips around, and reattaches in reverse orientation

chromosomal translocation

mutation where a segment of one chromosome breaks off and attaches to another chromosome

genetic material

must store information necessary for a cell to carry out its functions and must be able to replicate itself

griffith experiment

conducted with R and S strain; found genetic material was passed from nonliving S cells to living R cells

avery experiment

found only DNase treatment led to loss of transforming activity; proved DNA causes cell transformation

bacteriophages

viruses that infect bacteria by transferring their genetic material

hershey and chase experiment

found DNA (not proteins) is transferred by bacteriophage to bacteria; DNA is genetic material

A form of DNA

reduced hydration

B form of DNA

highly hydrated, under normal conditions

monosomy, trisomy

two types of aneuplodies

inversion, translocation

types of chromosomal structural rearrangements

radioactive isotopes

used to “tag” specific macromolecules; unstable but emit radiation to stabalize

³²P

specifically labels nucleic acids, not proteins

³⁵S

specifically labels proteins, not nucleic acids

x-ray crystallography

attempted to determine 3D structure of DNA through _________ ________________

antiparallel

DNA strands run _______ to one another

watson and crick

found that DNA is a double helix, sugar-phosphate backbone is outside, bases face inwards, each strand can serve as a template to make a new complementary strand