A scientific investigation is replicable if A.
the same investigation is conducted in two different laboratories by two different scientists and the same results are produced.

B.
one scientist performs many different experiments in his or her own laboratory.

C.
two different scientists perform different experiments in their own laboratories but they produce the same results.

D.
one scientist performs the same experiment in his or her own laboratory and different results are obtained.

Rease is an enzyme used by plants to break down urea (a nitrogen-containing compound) into carbon dioxide and ammonia. urease urea > > > carbon dioxide and ammonia ammonia is broken down by plants into a nitrogen source plants need to grow. thus, plants could not use urea as a nitrogen source unless it was first converted to ammonia. in soybean plants there are two different kinds of urease, one produced in the seeds and the other produced in the leaves of the plant. three types of soybean plants were used in a set of experiments: normal soybeans and two mutant strains, one lacking the urease in the seeds only (strain 1) and one lacking urease in the leaves only (strain 2). experiment 1 separate areas in a field were planted with normal, strain 1, and strain 2 soybeans. all types of soybeans appeared to grow, flower, and produce seeds equally well. there were no externally detectable differences among the strains. experiment 2 small pieces of plant leaves of equal weight were obtained from each type of soybean plant and separately placed on media in culture dishes. tissue growing in this way will become an unorganized clump of cells referred to as callus. to provide a controlled nitrogen source, half the tissue samples of each type were placed on media containing urea, and the other half of the samples were placed on media containing ammonia. after 30 days, the weight gain for each of the callus samples was determined. results are shown in the table below.

Dna replication or repair occurs in a cell in all of thw following situations except when

Which one of the following is true of trnas? a) trnas are double-stranded. b) each trna binds a particular amino acid. c) there are four types of trna. d) trnas carry special sequences known as codons. e) all of the above