2. (SC.8.N.1.1) When investigating a new cancer-fighting drug, medical researchers give some of the subjects a pill that contains the drug. Some
other subjects are given a pill that does not contain the drug. The drug-
free pill serves what purpose in the design of this investigation?
is it a controlled experiment, an experimental variable, a separate trial, or a qualitative comparison?

Which best explains why there are 64 possible codons in the genetic code and only 20 amino acids that make protiens of living organisms on earth

Coat color in cats is determined by genes at several different loci. at one locus on the x chromosome, one allele (x ) encodes black fur and another allele (xo) encodes orange fur. females can be black (x x ), orange (xoxo), or a mixture of orange and black called tortoiseshell (x xo). males are either black (x y) or orange (xoy). bill has a female tortoiseshell cat named patches. one night, patches escapes from bill\'s house, spends the night out, and mates with a stray male. patches later gives birth to the following kittens: one orange male, one black male, two tortoiseshell females, and one orange female. what are the genotypes of patches, the stray male, and the kittens?

This is the interaction of two organisms where one is and the other is neither nor harmed.