Eukaryotic sexual life cycles show tremendous variation. Of the following elements, which do all sexual life cycles have in common?
I. alternation of generations
C. II, III, and IV
Which of the following is missing from the life cycle listed below?
The phases of meiosis that produce the most genetic variation from crossing-over and independent assortment are
D. prophase I and anaphase I
Crossing-over occurs during which phase of meiosis?
A. prophase I
1. formation of four new nuclei, each with half the chromosomes present in the parental nucleus
2. alignment of tetrads at the metaphase plate
3. separation of sister chromatids
4. separation of the homologs; no uncoupling of the centromere
5. synapsis; chromosomes moving to the middle of the cell in pairs
From the descriptions above, which of the following is the order that most logically illustrates a sequence of meiosis
Which of the following occurs in meiosis but not in mitosis?
E. B and D above
How does the sexual life cycle increase the genetic variation in a species?
E. A, B, and C are correct
What are the sources of genetic variation in sexual life cycles of animals?
A. A, B, and C
Which of the following is true of a species that has a chromosome number of 2n=16?
E. a gamete from this species has 8 chromosomes
How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis?
A. they have half the number of chromosomes and one-fourth the amount of DNA