Tutorial: Mitosis - signal transduction

A. Mitosis/Meiosis 1. The process of mitosis ensures that:

a. each new cell is genetically different from its parentb. each new cell receives chromosomes to control lifec. cells will divide at the appropriate timed. DNA is replicated without errors

2. The image to the right illustrates what phase of mitosisa. anaphase b. interphase c. metaphase d. prophase

3. Which of the following phases would come next?a. prophase b. metaphase c. anaphase d. teleophase

4. Which of the following is NOT part of mitosisa. interphase b. prophase c. metaphase d. anaphase

5. Which of the following is NOT part of the chromosome?a. kinetochore b. chromatid c. centromere d. spindle fiber

6. A cell that has 20 chromosomes undergoes mitosis. Which of the following is true? a. 2 daughter cells will be created, each have 20 chromosomesb. 2 daughter cells will be created, each have 40 chromosomesc. 4 daughter cells will be created, each having 10 chromosomesd. 2 daughter cells will be created, each having 10 chromosomes

7. Spindle fibers (microtubules) form during which phase?a. G2 b. interphase c. prophase d. metaphase

8. Most cells spend most of their lives in which phase?a. prophase b. metaphase c. interphase d. telophase

9. Cytokinesis begins during which phase?a. telophase b. synthesis phase c. anaphase d. metaphase

10. During which stage of mitosis is the nuclear membrane broken into fragments?a. Anaphase b. Late Prophase c. Early Prophase d. Metaphase

11. During which stage of mitosis do nucleoli reappear?a. Telophase b. Anaphase c. Early Prophase d. Late Prophase

12. The number of chromosomes in a human cell is _______.a. 2 b. 4 c. 23 d. 46

13. The resting stage of the cell is known as the _______.a. prophase b. metaphase c. interphase d. telophase

14. During which stage of mitosis do chromatids separate to form two sets of daughter chromosomes?a. Telophase b. Anaphase c. Prophase d. Interphase

15. Genetic information is transferred from parent to daughter cells through the _______.a. nucleus b. mitochondria c. endoplasmic reticulum d. centrioles

16. Which of the following is the longest stage of mitosis?a. Prophase b. Telophase c. Metaphase d. Anaphase

17. The interphase and mitosis together constitute the cell cycle.a. True b. False

18. The nuclear membrane is formed around the newly-formed sets of daughter chromosomes during the telophase.

a. True b. False

19. During mitosis, loosely arranged strands of chromosomes become coiled, shortened and more distinct during the metaphase.

a. True b. False

Use the following diagram to answer the next 7 questions. Note that the pictures are NOT in order.

1 2 3 4 520. At what stage of mitosis is cell 2?

a. Prophase b. Telophase c. Metaphase d. Anaphase e. Interphase

21. In cell 1 what is the structure labeled X?a. Chromosomes b. Spindle Fibers c. Chromatid d. Centrioles

22. At what stage of mitosis is cell 4?a. Prophase b. Telophase c. Metaphase d. Anaphase e. Interphase

23. In cell 3 what is the structure labeled Y?a. Chromatid b. Centrioles c. Spindle Fibers d. Chromosomes

24. At what stage of mitosis is cell 3?a. Prophase b. Telophase c. Metaphase d. Anaphase e. Interphase

25. Which of the above phases would come next?a. 1 b. 2 c. 3 d. 4 e. 5

26. The _______ gives an animal cell support and helps it to maintain shape.a. Cytoplasm b. Chloroplasts c. Cell wall d. Cytoskeleton

27. A student observes a cell undergoing mitosis. Which evidence shows that the cell is a plant cell?a. Absence of spindle fibers b. Formation of a cell platec. Replication of chromosomes d. Disappearance of the nuclear membrane

29. When cells grow to a certain size, they must divide because _______.a. There are too many organelles b. The pressure inside crushes the nucleus

Y

X

c. The cell membrane surface area is too small d. The cell membrane surface area is too large

30. A normal human cell contains 46 chromosomes in its nucleus. In mitosis, a body cell produces ______.a. Two cells with 23 chromosomes each b. Two cells with 46 chromosomes eachc. Four cells with 23 chromosomes each d. Four cells with 23 chromosomes each

31. DNA replication occurs during ______.a. Prophase b. Telophase c. Metaphase d. Anaphase e. Interphase

32. If pigs have 36 chromosomes in their normal muscle cells, how many would be found in a sperm cell?a. 46 b. 23 c. 36 d. 18

33. The paragraph below contains 11 serious errors. All have been underlined. correct each error by numbering 1 – 11 & then writing the correct word or phrase on the appropriated line. Your correct answers will each be worth 1 pt = 11 pt total.

Cytokinesis in eukaryotes occurs just prior to mitosis; cell division in prokaryotes occurs by a more complex process called, binary fusion. Between divisions, eukaryotic cells are in dormant-phase, an active period during which cells grow in size and chromosomal DNA is duplicated, the cell mass decreases, and new organelles are produced. Nuclear DNA is replicated only during S phase, whereas mitochondrial and ribosomal DNA is replicated mostly in the G2 phase. The process of mitosis occurs in the following order: prophase, anaphase, metaphase, and telophase. The mitotic spindle is a complex of microfilaments that prevents chromosome movement. The spindle is attached to each chromosome at site called the connecotocore. Following nuclear division, the cytosol of the cell is divided. The soon-to-be daughter cells are separated by the cleavage furrow in animal cells and the cell plane in plant cells.

B. Signal Transduction

1. When a chemical messenger (or ligand) reaches a target cell, it binds to a receptor. A hydrophobic ligand binds to a(n)________, whereas a hydrophilic ligand binds to a(n) ___________.

A. intracellular receptor; transmembrane receptorB. transmembrane receptor; intracellular receptorC. agonist receptor; antagonist receptor

autocrine receptor; paracrine receptor 

2. How does a ligand-gated ion channel work? A. When a ligand binds to an ion channel, an enzyme facilitates the passage of ions across the membrane.

 When a ligand binds to an ion channel, the channel interacts with a G-protein that subsequently opens another ion channel nearby, allowing ions to cross the membrane.

B. A ligand-gated ion channel is generally open and allows ions to cross the membrane. However, in the presence of a ligand, an ion channel will close.

C. When a ligand binds to an ion channel, the channel changes conformation and the ion channel opens, allowing ions to cross the membrane.

3. ____________ rely on ___________, such as Ca2+, cyclic GMP, phosphatidylinositol, and cyclic AMP, to activate (or inactivate) a variety of pathways within the cell.

A. Intracellular receptors; ligandsB. G-protein-coupled receptors; second messengersC. Receptor-enzymes; G-proteinsD. G-protein-coupled receptors; G-proteins

4. Communication among neurons and between neurons and other target cells occurs across short distances at a structure called the __________, a region where the signaling cell and the target cell are very close together.

A. SynapseB. neurotransmitterC. catecholamineD. neural receptor

  5. Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction

because: A. they are species specificB. they always lead to the same cellular responseC. they amplify the original signal manyfold D. they counter the harmful effects of phosphatases.E. the number of molecules used is small and fixed.

6. Signal transduction pathways benefit cells for all of the following reasons exceptA. they help cells respond to signal molecules that are too large or too polar to cross the plasma membrane. B. they help cells use up phosphate generated by ATP breakdown. C. they enable different cells to respond appropriately to the same signal.D. they can amplify a signal.E. variations in the signal transduction pathways can enhance response specificity.

7. Consider this pathway: epinephrine -> G-protein-linked receptor -> G protein -> adenylyl cyclase ->cAMP. Identify the second messenger.

A. cAMP B. G protein C. GTP D. adenylyl cyclaseE. G-protein-linked receptor

8. A signal transduction pathway is initiated when a __________ binds a receptor.A. cAMP B. Tyrosine kinaseC. Protein kinaseD. Signal molecule

9. A signal molecule is also known as a A. ReceptorB. LigandC. Protein kinaseD. Initiator

9. Which of the following is an example of long distance signaling occurring in the body?A. Endocrine B. Paracrine C. AutocrineD. Exocrine

10. At which stage of cell signaling do signal molecules bind certain proteins in the cell membrane, causing the protein to change shape?

A. ResponseB. TransductionC. Reception D. Phosphorylation

10. At which stage of cell signaling are second messengers involved?A. ResponseB. Reception C. TransductionD. Dimerization

11. Regulation of gene expression would occur during which stage of cell signaling?A. ResponseB. TransductionC. Reception D. Ligand binding

12. Which of the following receptor types undergo dimerization (associate with another receptor) upon ligand binding.

A. Receptor tyrosine kinasesB. G protein-coupled receptorsC. Second messengersD. Ion channel receptors