Question

1). Explain the significance of the fact that gametes contain half of the chromosome complement of somatic cells. Tell me something about variation, if you have a sibling (if you don't imagine you do) - how is your sibling's genetic make-up similar and/or different from yours? What about your mom and dad?

2). Explain the terms reductional division and equational division. What is reduced or kept equal? To which nuclear divisions do these terms refer?

3). What is the diploid number (2n = ?) of an organism if it has
a) 12 chromosomes at Anaphase of Mitosis?
b) 12 chromosomes at Anaphase I of Meiosis?
c) 12 chromosomes at Anaphase II of Meiosis?

4). Compare/contrast Metaphase I of Meiosis with Metaphase of Mitosis.

5). What are the two mechanisms of variation in Meiosis, and during which stage(s) does each occur?

6). Draw a diagram of a bivalent and label the following parts: centromere, sister chromatids, non-sister chromatids, homologous chromosomes, chiasma.

7). A diploid cell has 1 pair of acrocentric chromosomes (Chromosome 1) and 1 pair of submetacentric chromosomes (Chromosome 2).
· Gene X is on Chromosome 1. Gene Y is on the short arm of Chromosome 2 and Gene Z is on the long arm of Chromosome 2.
· The maternal chromosomes have the X, y, z alleles, whereas the paternal chromosomes have the x, Y, Z alleles.
Draw these chromosomes, labeling ALL alleles, as they might appear in Metaphase I of Meiosis.