Why do scientists use control groups in experiments?

Most of the carbon on earth is stored in the form of

Which best example best demonstrates the importance of having knowledge of evolutionary relationships? a. illustration of a plant b.organ transplantation between species c. blood donation from a human d. do you need sequence of an insect.

Use the above pedigree for questions 1,2, and 3 1. what kind of genetic disorder is represented in the pedigree? a. recessive b. dominate refer to the pedigree in question 1. 2. is the mutated gene in this disorder located on a sex chromosome (x or y) or an autosome? a. sex chromosome b. autosome refer to the pedigree in question 1. 3. which generation has individuals that you are certain are heterozygous for the mutated gene? a. generation 1 b. generation 2 c. generation 3