Ascientist performs a controlled experiment. this means that select one: a. the experiment is repeated many times to ensure that the results are accurate. b. the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data. c. two versions of the experiment are conducted, one differing from the other by only a single variable. d. one experiment is performed, but the scientist controls the variables.

Hurry which of these is true about index fossils? a) are very scarcely found b) used as guides in relative dating c) found in the youngest layer of the rock d) used as reference points in absolute dating

Plz genetic engineering can be applied to many fields including medicine and agriculture. which of the following is a medical application of genetic engineering? a. giving crop plants recombinant dna so that they would be resistant to herbicides. b. examining a persons pedigree to determine whether they can carry a gene for a genetic disease. c. analyzing a persons dna to see how closely they are related to another person. d. certain genes into bacteria so that they will produce a needed medicine.

Along what geographical feature are most of the oil producing regions located