Scientists have reportedly isolated short fragments of dna from fossilized dinosaur bones hundreds of millions of years old. the technique used to isolate this dna is the polymerase chain reaction, which is capable of amplifying very small amounts of dna a million‑fold. critics have claimed that the dna isolated from dinosaur bones is not purely of ancient origin but instead has been contaminated by dna from present‑day organisms, such as bacteria, mold, or humans. what precautions, analyses, and control experiments could be carried out to ensure that dna recovered from fossils is truly of ancient origin

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?

The response is the basis for vaccination. primary secondary tertiary none of the above

Ronald wants to see if a new shower cleaner works better in removing soap than his old cleaner. he uses the new cleaner on one half of the shower tiles and his old cleaner on the other half. identify the independent and dependent variables in this experiment. enter your answer in the space provided.