5 Written Questions

1. the loss of one or more nucleotides from a gene by mutation; the loss of a fragment of a chromosome
2. an abnormal mass of cells that forms within otherwise normal tissue
3. error in meiosis (nondisjunction) produces a gamete (generally an egg) with two copies of chromosome 21 n = 24 rather than 23. if the abnormal gamete combines with a normal gamete (n=23) the zygote will have 47 total chromosomes
4. a display of micrographs of the metaphase chromosomes of a cell, arranged by size and centromere position
5. in the life cycle of an organism that reproduces sexually, a cell containing a single set of chromosomes; an n cell

5 Matching Questions

1. autosome
2. locus
3. tetrad
4. mitotic spindle
5. centromere

1. a a chromosome not directly involved in determining the sex of an organism: in mammals, for example, any chromosome other than X or Y
2. b the particular site where a gene is found on a chromosome. homologous chromosomes have corresponding gene loci
3. c a paired set of homologous chromosomes, each composed of two sister chromatids. tetrads form during prophase I of meiosis
4. d a spindle-shaped structure formed of microtubules and associated proteins that is involved in the movements of chromosomes during mitosis and meiosis
5. e the region of a chromosome where two sister chromatids are joined and where spindle microtubules attack during mitosis and meiosis. the centromere divides at the onset of anaphase during mitosis and anaphase II of meiosis

5 Multiple Choice Questions

1. a change in a chromosome resulting from a chromosomal fragment attaching to a nonhomologous chromosome. can occur as a result of an error in meiosis or from mutagenesis
   1. translocation
   2. deletion
   3. fertilization
   4. duplication
2. the part of the cell cycle when mitosis divides the nucleus and distributes its chromosomes to the daughter nuclei, and cytokinesis divides the cytoplasm, producing two daughter cells
   1. mitosis
   2. mitotic spindle
   3. mitosis (M) phase
   4. metaphase
3. a threadlike, gene-carrying structure found in the nucleus of a eukaryotic cell and most visible during mitosis and meiosis. Also, the main gene-carrying structure of a prokaryotic cell. Chromosomes consist of chromatin
   1. sex chromosomes
   2. chromosome
   3. chromatin
   4. autosome
4. the combination of DNA and proteins that constitute chromosomes; often used to refer to the diffuse, very extended form taken by the chromosomes when a eukaryotic cell is not dividing
   1. chromosome
   2. chromatin
   3. duplication
   4. mitosis
5. the spread of cancer cells beyond their original site
   1. metastasis
   2. meiosis
   3. metaphase
   4. mitosis

5 True/False Questions

1. telophase → the fourth and final stage of mitosis, during which the daughter nuclei form at the two poles of a cell. Telophase usually occurs together with cytokinesis

   True        False

2. mitosis → the division of a single nucleus into two genetically identical daughter nuclei. mitosis and cytokinesis make up the mitotic (M) phase of the cell cycle

   True        False

3. sexual reproduction → the creation of offspring by a single parent, without the participation of sperm and egg

   True        False

4. cell cycle control system → an orderly sequence of events (including interphase and the mitotic phase) from the time a eukaryotic cell divides to form two daughter cells to the time those daughter cells divide again

   True        False

5. sex chromosomes → a threadlike, gene-carrying structure found in the nucleus of a eukaryotic cell and most visible during mitosis and meiosis. Also, the main gene-carrying structure of a prokaryotic cell. Chromosomes consist of chromatin

   True        False