Topic 5 Cell Division

What are some reasons that cells typically divide? Growth Repair/replacement to reproduce

Circle one: The longest phase of the cell cycle is INTERPHASE / M phase

G1 is about cell __growth__.

How does a duplicated strand of DNA end up being identical to the original strand? In DNA replication one strand serves as a template for a new strand to be made, resulting in two DNA strands each with one old and one new strand.

The last stage of Interphase is G2.

In mitosis, the goal is to get cells that are genetically __identical __That is, we want to go 2N2N.

Match the following Mitosis stages to what happens C--Prophase a. Chromosomes move to opposite ends of cell D---Metaphase b. Nucleus reforms, DNA loosens, last stage A---Anaphase c. DNA condenses; nuclear breaks down B--Telophase d. Chromosomes line up in middle of cell

What is the difference between plant and animal cytokinesis? In cells without walls (animal cells ), it is accomplished by pinching of the cell. In plant cells, the wall prevents pinching; instead a new cell wall forms.

What does meiosis do to the number of chromosomes? Reduces the number of chromosomes by half, diploid cells become haploid

Meiosis goes from 2N N, or from diploid  haploid.

What is crossing over? process in which homologous chromosomes exchange pieces of their chromatids

When does crossing over happen? Prophase I