13. If a fossil originally had 456 g of radium which had a half-life 3 years. How many half-lives would have occurred when there was only 7.1 g of radium left? How old is the
fossil? Fill out the parent/daughter table to help

Which of these substances does not protect against invaders in the nonspecific immune response? a. saliva b. mucus c. tears d. urine

Drag the tiles to the correct boxes to complete the pairs. match each cell organelle with its description.

An organism's reproductive strategy includes all of the following except a. the number of offspring produced. b. the amount of energy expended in producing offspring. c. the length of time parental care is given d. the number of alleles an organism passes on.