Cell Division Test Review

STATION 1 1. Starting with a single body cell, after three divisions, how many cells would be produced? ANSWER: 8 2. Mitosis allows organisms to repair themselves by ANSWER: Making new skin cells identical to the original where the cut in the skin was made.

STATION 1 3. Which of the following is true concerning cancer cells? ANSWER: They result from loss of cell cycle control. 4. A drug called colchicine is used to stop cell division. It works by interfering with the formation of the spindle fiber. If cells are given colchicine, given the stages below, when will mitosis be stopped? ANSWER: Metaphase

STATION 1 5. In the human species, all somatic cells have 46 chromosomes. Which of the following can also be true? ANSWER: All gametes cells in humans have 23 chromosomes.

STATION 2 6. How does the sexual life cycle (Meiosis) increase the genetic variation in a species? ANSWER: By the process of crossing-over. 7. Observe the karyotype below. What can be concluded about this person? ANSWER: Normal Male

STATION 2 8. Observe the figure below. The type of cells represented by the letter B in the figure are haploid. 9. The type of cell found in the zygote in the figure is diploid.

STATION 2 10. Consider the cell labeled X in the figure below containing 4 chromosomes. Which of the four cells (A,B,C or D) below it represents a healthy gamete that could be produced from this cell? ANSWER: A

STATION 3 ** 11. Mitosis is a type of cell division needed to create body cells for Eukaryotes. Mitosis is the division of the nucleus. It is divided into 4 phases. In Prophase, the first phase, the chromosomes become visible and the nuclear membrane breaks down. In the second phase, Metaphase, the chromosomes line up in the middle of the cell. In the third phase, Anaphase, the chromosomes separate and move towards opposite ends of the cell. In the final phase, Telophase, the chromosomes reach each end of the cell and a nuclear membrane reforms around each of the chromosomes.

STATION 4 12. Haploid means having 1 set of chromosomes. Gametes (sex cells/sperm/egg) are the only cells in the human body that are haploid. Gametes are haploid or contain only 23 chromosomes because when a sperm and egg unite (23+23=46), each of their sets of chromosomes combine to form a diploid zygote (fertilized cell). Diploid means having 2 sets of chromosomes. Somatic (body) cells are diploid. They are diploid because a haploid sperm (23) and haploid egg (23) combine to form a diploid body cell with 46 chromosomes.

STATION 5 13.

STATION 6 14. Cancer is caused by an error in the cell cycle. The proteins that regulate cell growth and division are coded for by genes. If a mutation occurs in one of these genes, the proteins may not function properly. Cell growth and division may be disrupted as a result. Such a disruption could lead to cancer, the uncontrolled growth of cells.

STATION 7 ** 15. Mitosis is the division of the nucleus. The function of Mitosis/cell division is for growth, repair and development. Mitosis has four phases (Prophase, Metaphase, Anaphase and Telophase). In prophase, chromosomes become visible. In metaphase, the chromosomes line up in the middle of the cell. In anaphase, the chromosomes separate and move to opposite ends of the cell. In telophase, the chromosomes reach opposite ends of the cell and the nuclear membrane reforms. The type of cells that undergo Mitosis are somatic (body) cells. Mitosis happens in every cell in the body except for the sex cells. There are two daughter cells produced at the end of Mitosis and they are identical to the parent cell. The daughter cells have the same number of chromosomes as the parent (in humans the number is 46) making them diploid. The nucleus divides once during mitosis.

STATION 7 #15 continued… The function of Meiosis is to create gametes. In Meiosis I, one cell divides into two. During Prophase I, genetic material is exchanged between chromosomes creating genetic variation. This is called crossing-over. In Meiosis II, two cells divide into four. The type of cells that undergo Meiosis are gametes (sex cells/sperm/egg). Meiosis happens in the testes of males and ovaries of females. Four different daughter cells are produced at the end of Meiosis. Each daughter cell has half the number of chromosomes (in humans 23 chromosomes) making them haploid. The nucleus divides twice during meiosis.

STATION 7 #15 continued… Mitosis and Meiosis have many similarities. They are both types of cell division in eukaryotes. Interphase (G1, S, G2) occur the same before Mitosis and Meiosis. Cytokinesis occurs the same after Mitosis and Meiosis. Both have the same phases (Prophase, Metaphase, Anaphase and Telophase).