Watch this video C about the stresses on the body caused by carrying heavy backpacks. Then design an investigation about the effect of carrying backpacks on students' health using these steps of the scientific method:
• make observations or inferences
• ask questions
. construct hypotheses and make predictions
• test hypotheses
• analyze results
Your investigation can address any question you have about backpacks and student's health that you choose.

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?