These are barrel shaped microtubules in most animal cells, that organize the spindles during cell division.

The earth consists of a variety of different organisms. despite their diversity, however, some similarities on the structural and metabolic levels may be seen. these similarities can be attributed to a. similarities among organisms in their proteins and nucleic acids. b. the ability of organisms to readily adapt to sudden environmental changes. c. similarities in organisms' habitats and niches. d. the ability of all organisms to interbreed and produce new species.

Complete the statements to identify the first two steps of meiosis i. (1 ) the first and longest step of meiosis i is called i. (2)the second step of meiosis i is called i.

What is the main function of the central vacuole in a plant cell? a. absorbs energy from the sun to produce food b. holds water and maintains turgor pressure c. breaks down molecules to release energy d. contains the cell's genetic material