Meiosis Student Exploration

Vocabulary: anaphase, chromosome, crossover, cytokinesis, diploid, DNA, dominant, gamete, genotype, germ cell, haploid, homologous chromosomes, interphase, meiosis, metaphase, mitosis, ovum, phenotype, prophase, recessive, sister chromatid, sperm cell, telophase, zygote Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. During mitosis, a single cell divides to produce two daughter cells. What must happen in the original cell so that each of the daughter cells has a complete set of chromosomes? DNA must replicate. 2.During sexual reproduction, two sex cells fuse to create a fertilized cell with a complete set of chromosomes. What must be true about the number of chromosomes in each sex cell? It has to half as many chromosomes as the parent cell. Gizmo Warm-up Meiosis is a type of cell division that results in four daughter cells with half as many chromosomes as the parent cell. These daughter cells mature into gametes, or sex cells. In the Meiosis Gizmo, you will learn the steps in meiosis and experiment to produce customized sex cells and offspring. On the STEPS tab, click Male. You are looking at a germ cell, or a cell that will undergo meiosis to become gametes. 1. Read the description of interphase at the bottom of the Gizmo. What happens to the cell at the beginning of interphase? The cell grows and synthesize mRNA chromosomes are copied. 2.Click on the DNA in the nucleus of the cell. Describe what happens.The nuclear envelope breaks down and DNA condenses into chromosomes. 3.Why is it necessary for the cell to grow and duplicate its DNA before the start of meiosis? DNA duplicates before a cell divides is to give a complete set of chromosomes to each daughter cell.