Concepts of Biology (BIOL115) - Dr. S.G. Saupe (ssaupe@csbsju.edu); Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321

Cell Division Study Questions

Lecture Outline:

I.  Common features in all cells
     A.  Duplicate genetic information (DNA replication)
     B.  Divide the information into daughter cells (fission/mitosis/meiosis)
     C.  Divide the cytoplasm (cytokinesis)

II.  Binary fission ‑ cell division in prokaryotes

III. The cell cycle: interphase (G1, S, G2), mitosis/meiosis, cytokinesis

IV.  Mitosis    
     A.  Chromosome structure
     B.  Phases of mitosis (prophase, metaphase, anaphase, telophase)
     C.  Cytokinesis    
     D.  Differences between plant and animal mitosis

V.   Meiosis
     A.  Sexual life cycle
     B.  Phases of meiosis ‑ meiosis I & II
     C.  Law of Segregation
     D.  Law of Independent Assortment
     E.  A comparison of mitosis and meiosis
     F.  Human gamete formation
          1.  Oogenesis
          2.  Spermatogenesis    

VI.  When meiosis goes awry ‑ non‑disjunction
     A.  Sex chromosomal nondisjunctions (XXX, XO, XXY, XYY)
          1.  Barr bodies
          2.  Calico cats    
          3.  Some jargon ‑ gene, allele, homozygous, heterozygous, phenotype,  genotype
     B.  Autosomal nondisjunctions (i.e., trisomy 21)
     C.  Karyotypes ‑ looking at the chromosomes

Required Readings:  text:  12 & 13

Goal of the Unit:  The goal of this unit is to provide an introduction to the process by which cells divide.

Important Terms and Concepts: (can you use them conversationally?  Can you create mini‑dialogues with these terms?  How about making a tape with your group members for fun?  Or make a concept map?)

Some General Study Tips:  The following are a few tips for preparing for the next exam.

1. Make a sketch of mitosis & meiosis

2. Make a table comparing and contrasting meiosis and mitosis

3. Sketch out non‑disjunction of sex chromosomes during meiosis and predict possible offspring. 

4. Make a concept map for cell division, mitosis, meiosis (or any other topic)

5. Draw the general sexual life cycle

Caution:  The material in this and the next few units is not readily "crammable."  I encourage you spend some time with this material prior to "exam‑eve".

Learning Objectives:  Upon completion of this unit you should be able to:

1. indicate the sex chromosome composition of a normal male and female, and individuals with Turner's Down's, Klinefelter's and Triplo‑X syndromes.

2. describe the procedure used to prepare a karyotype.  Explain the role of colchicine in the process and why white bloods cells but not red ones are used for the procedure.

3. describe the difference between haploid and diploid.  Provide examples of each.

4. describe the phases of mitosis, the events occuring during each and the significance of this process.

5. describe the phases of meiosis, the events occuring during each and the significance of this process.

6. indicate when, where and why meiosis and mitosis occur in humans

7. compare and contrast mitosis and meiosis.  How are they similar?  How do they differ?

8. describe the cell cycle and the events occurring during this process.

9. relate the cell cycle to mitosis and meiosis.

10. describe the process of spermatogenesis

11. describe oogenesis

12. predict the offspring resulting from the fertilization of a gamete produced by the non‑disjunction of sex chromosome during either meiosis I or II in both males and females and normally produced gametes.

13. What is a Barr body?

14. describe how a bacterial cell divides

15. Sketch the following mosquito cells (2n=6).  For each indicate whether the cell is haploid or diploid, the chromosome number, and number of DNA molecules present.
         egg cell in prophase I
         abdomen cell in interphase
         egg cell in metaphase II
         tongue cell in anaphase. 

16. distinguish between centrosome, centriole, centromere, chromosome, and chromatid

17. describe the typical sexual life cycle including the following: meiosis, fertilization, haploid, diploid,   gametes, sperm, eggs, 2N, N

18. indicate how oogenesis differs from spermatogenesis

A Non‑Disjunction Question:  
     Assume that a non‑disjunction of the sex chromosomes occurs during meiosis I in a male.  Further assume that these sperm fertilize normally produced eggs.  List the genotypes (i.e., XY, XX, XXX), phenotypes (i.e., normal or name of disorder), whether male or female, # chromosomes in the fertilized zygote, and the probability of the occurrence for all possible offspring.  Note: not all rows in the table will necessarily be used.