How many half-lives does it take for a radioactive substance to decay until only one quarter of the original substance remains?

Select all the correct answers. lactobacillus is a bacteria that live inside humans. these bacteria live on the nutrients from our bodies. they to keep our gut clean and healthy. s. typhi is a bacteria that enter our bodies through contaminated food. this bacteria causes infections in the body. based on this information, which two statements about the association between these bacteria and humans are true? a. lactobacillus shares a parasitic relationship with humans. b. s .typhi shares a parasitic relationship with humans. c. both lactobacillus and s. typhi share a parasitic relationship with humans. d. both lactobacillus and s. typhi share a mutualistic relationship with humans. e. lactobacillus shares a mutualistic relationship with humans, and s. typhi shares a parasitic relationship multiply chrse

If assuming tasting ptc as a simple gene trait,what other genotype would you select to put in this missing genotype box that could result in this phenotype

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction.