How might the genetic content of these change by the time tetrads have aligned at the metaphase plate during metaphase I?
Biology 1107K Sections C & J Homework #3 Fall 2011
Mitosis and Meiosis Problem Set
You may work through these problems singly or as pairs and hand in one set of answers per pair (if you choose to work as pairs). Please type your answers in complete, grammatically correct sentences.
WORTH: 25 points DUE: Tuesday November 8, 2011. Do NOT email me your assignments!
If an organism has a diploid number of 16, how many chromatids are visible at the end of mitotic prophase? How many chromosomes are moving to each pole during anaphase of mitosis?
Contrast the genetic content and the origin of sister versus nonsister chromatids during their earliest appearance in prophase I of meiosis. How might the genetic content of these change by the time tetrads have aligned at the metaphase plate during metaphase I?
Given the end results of the two types of division, why is it necessary for homologs to pair during meiosis and not desirable for them to pair during mitosis?
Explain why meiosis leads to significant genetic variation while mitosis does not.
A diploid cell contains three pairs of homologous chromosomes designated C1 and C2, M1 and M2, and S1 and S2; no crossing over occurs. What possible combinations of chromosomes will be present in (a) daughter cells following mitosis, (b) the first meiotic metaphase, (c) haploid cells following both divisions of meiosis? Draw or explain your work.
Was it an evolutionary necessity that meiosis evolved at the same time as sexual reproduction? Why or why not?
Meiosis Case Study: Rattlesnake Surprise
David Chiszar, a professor in the psychology department at the University of Colorado, got a big surprise when he walked into his laboratory in 1995. His laboratory shelves are lined with dozens of glass cases; behind the glass, the subjects of Dr. Chiszarâs research coil a safe distance from the professor and any visitors brave enough to enter.