The sodium-potassium pump establishes concentration gradients:
(a) of higher sodium concentrations inside the cell and higher potassium concentrations outside the cell
(b) of sodium and potassium but the area of their concentrations (inside or outside) depends on the needs of the cell
(c) of higher potassium concentrations inside the cell and higher sodium concentrations outside the cell
(d) by pumping sodium outside the cell and potassium is cotransported out as well

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.

After a group of researchers conducts a new experiment that has never been conducted before, what is the best way for other scientists to make sure that the data is real

In a certain plant, yellow leaves are dominant (y) and red leaves are recessive (y). a plant with genotype yy and a plant with yy are crossed. if they have four offspring, how many would you predict would have red leaves? a: 1b: 0c: 3d: 2