Indicate whether the statement is true or false. ____ 1. Diffusion over large distances is slow and inefficient because it relies on random movement of molecules and ions.
____ 2. The cell cycle is divided into interphase and mitosis.
____ 3. During prophase in an onion root tip cell, centrioles migrate to the poles of the cell.
____ 4. In plant cells, cytokinesis begins with a furrow that pinches the cell.
____ 5. Stem cells are only of one type: embryonic.
____ 6. Embryonic stem cells are found in various tissues in the body and might be used to maintain and repair the same kind of tissue in which they are found.
____ 7. A gamete has one-half the number of chromosomes of a regular body cell.
____ 8. Homologous chromosomes are two chromosomes with identical DNA sequences.
____ 9. Recent research suggests that beneficial mutations accumulate faster when species undergo sexual reproduction rather than asexual reproduction.
____ 10. During meiosis, chromosome number is reduced through three rounds of cell division.
____ 11. Sexual reproduction would be more advantageous than asexual reproduction for organisms living in an environment that is diverse and undergoes frequent changes.
____ 12. Mendel’s work on garden pea plants resulted in the discovery that genetic traits of parents always blend together in subsequent generations.
____ 13. In humans, the ability to roll one’s tongue is a dominant trait. Therefore, a tongue roller can only have children who are also tongue rollers.
____ 14. The separation of genes during crossing over occurs more frequently between genes that are far apart on a chromosome than for genes that are close together.
____ 15. Polyploidy is more common in plants than animals.
____ 16. Polyploid plants such as coffee and strawberries are often less healthy and smaller than diploid plants of the same species.
____ 17. During meiosis I, homologus chromosome pairs are separated when the centromeres split apart.
____ 18. Meiosis occurs during both sexual reproduction and asexual reproduction.
____ 19. Gregor Mendel’s research supports the idea each organism carries a pair of alleles.
Identify the choice that best completes the statement or answers the question. ____ 20. By the end of prophase, each of the following has occurred except ____.