A uranium-lead age determined from a zircon crystal removed from a sandstone would reflect the time elapsed since the ________ of the zircon.
A) erosion
B) deposition
C) crystallization
D) cementation
Question 2
In order to use a radioactive-decay scheme to calculate the age of a mineral all of the following conditions must be met except
A) the half-life must be known.
B) no daughter isotope present prior to the start of parental decay or the amount of daughter can be determined.
C) no parent or daughter isotopes can be gained or lost from the mineral once decay starts.
D) only one radioactive isotope can exist in the rock so that cross-decay doesn't occur.
Time-course of reprogramming mouse fibroblasts into induced pluripotent stem cells
The principle of faunal succession uses animal fossils to tell relative time.
Telomere length is related to the amount of time adults spend in leisure time activity. Source: Ada
Time course of HIV infection.
A model of transcription initiation as deduced from the crystal structure of TFIIB complexed
Estimated number of new HIV infections per year over time period in Canada