Help me pls ASAP !!

If it takes 700 million years for half of your the uranium in a rock to decay into lead how old is a fossil that is:

a.) 50% uranium and 50% lead

b.) 25% uranium and 75% lead

Lucia is walking barefoot in her yard. she accidentally steps on a nail. how will her nervous system work to generate a reaction? arrange the eventschronologically.

During binary fission, what events must occur before the cell splits into two new cells?

Atest cross can be used to -predict the phenotypes of a monohybrid cross -predict an unknown genotype of a purebred dominant plant -cross-breed dominant and recessive plants -give probabilities that a trait will appear