2.  Chromosomes are the structure in which DNA is packaged.  Centromere is the region where sister chromatid are bound together.  Gene is a segment of DNA that codes for RNA and protein.  Chromatin is a substance made up of DNA and protein.  Nucleosome is a structural unit made of DNA wound around a core of histone proteins.  Chromatid is a thick strand made up of condensed DNA.  Histone is a type of protein found in the chromosomes of eukaryotic cells.

3.  Interphase is a major portion of a cell’s life.  Cell cycle is a repeating sequence of cellular growth and division.  Cytokinesis is the process by which cytoplasm is divided between daughter cells.  Centrosome is an organelle that helps assemble the spindle and aids chromatid movement in a dividing cell.  Spindle is a microtuble network that pulls chromatids in a dividing cell.  Mitosis is the process by which the nucleus of a cell becomes two nuclei.

4.  Why do multicellular organisms produce new cells? To advance growth of an organism, replace old cells or cells not working well, and heal a tear or wound.  In prokaryotic cells, DNA appears in the form of a  loop  In eukaryotic cells, DNA is wrapped around  Proteins  What do all cells do to prepare for cell division?  Make an extra copy of their complete DNA  What pinches a dividing prokaryotic cell into two cells?  The cell wall

5.  Mitosis occurs  After the second gap phase of interpase.  Which of these events does NOT occur during interphase?  The cytoplasm is divided  During which stage of mitosis do nuclear envelopes form?  Telophase  What is the first stage of mitosis?  Prophase

7.  What is the protein that aids in the packing of DNA called?

8.  Histone

9.  Starting at the first phase, name the three phases of Interphase and what occurs at each phase.

10.  G 1 Gap one phase  The size of the cell increases  SSynthesis  The cell’s DNA replicates  G 2 Gap two phase  The cell checks to make sure DNA is copied correctly and environmental conditions are A-OK for cell reproduction. If the cell’s DNA needs a touch up, what structure is responsible for this duty?

11.  Put the above terms in proper sequence and identify where each is found in  Interphase  Mitosis  Cytokinesis

12.  Interphase has chromatin only.  Cytokinesis has chromatin only.  In prophase, the chromatin condenses to form chromatid and when joined with a centromere, form chromosomes.  In metaphase, there are chromosomes.  In anaphase, there are chromosomes.  In telophase, as the cell separates, the chromosomes turn back into chromatin.

13.  What is the difference between a tumor and cancer?

14.  Tumors are masses of rapidly dividing, abnormal cells.  Cancer is a group of diseases involving uncontrolled cell growth.

15.  What is meant by a cell cycle?

16.  A cell cycle is a continuous repeating sequence of cell growth and cell division.

17.  Before cell division, what do both prokaryotic and eukaryotic cells need to do?

18.  Copy their DNA

19.  What are two structures within the cell that are involved in the movement of chromosomes during cell division?

20. The spindle pulls the chromosome apart at the centromere during what phase???????

21.  What are feedback signals and what are they used for?

22.  Feedback signals are signals to the cell that can be influenced by environmental or nutrient factors that can either start or delay the cell cycle.

23.  In which phase does the nuclear membrane and nucleolus start to disappear?

24.  In prophase—also this is where you can first see what??????

25.  Starting with G 1 in Interphase, list the other phases in the cell cycle in order.

26.  G 1  S  G 2  Mitosis  Cytokinesis