Carbon 14 isotope is used to determine the age of dead plants like fossils and animals and stones etc. The age determination of very old objects based on carbon 14 isotope is called carbon dating.
It would most likely be A. 10grams considering grams is the smallest and we are talking about a feather.
Well there alot of challenges faced by biologist researchers during the research of infectious disease, however major of those include the followings:
1- Defining and measuring the fitness for pathogens across the scales
2- Developing models to capture the impact of co-infection on the evolutionary process
3- Modeling how pathogen characteristics shape the evolution of hose immune diversity
4- Understanding the maintenance of pathogen diversity
5- Developing the better models for the impact of genetic systems on pathogen evolution .
