Which of the following statements best describes the nucleus of a cell? A. The nucleus has a membrane that allows for active transport of RNA and proteins.
B. The nucleus exports lysosomes which direct amino acid production within the cell.
C. The nucleus is responsible for supplying the cell with chemical energy in the form of ATP.
D. The nucleus contains some of the genetic material in a cell; the majority is contained in the cytoplasm.

How is ribosomal rna useful as a molecular clock? a. a large portion of the dna ring is not vital to structure or function, allowing it to accumulate neutral mutations. b. its rate of mutation increases over time as organisms continue to evolve and differentiate from each other. c. a slow mutation rate makes it useful for determining evolutionary relationships between ancient species. d. it is only found in select organisms, making it easier to compare relationships between species that have it.

Linda and julia are trying to determine whether their ideas are scientific or pseudoscientific. linda's idea is free of bias. julia's idea gives the same result when tested repeatedly. which statement is correct about linda and julia's idea?

What is a population? a. all the members of the same species living in the same ecosystem at the same time b. the number of a species living in the same ecosystem over a period of time c. the total number of organisms living in an ecosystem at a point in time d. all the members of a food web in the same ecosystem