Chapter 10 Cell Growth and Division Section 10-1 & 10-2

Friday, 10/23/15 Learning Target: Know the reasons for why cells divide. Learning Outcome: I will know limitations to cell growth and structure of chromosomes. https://www.youtube.com/watch?v=xuG4ZZ1GbzI

Cell Growth Cells divide rather than get larger because……. Demands on DNA would be too great. Cell would have trouble moving food and waste across the cell membrane.

Volume increases faster than surface area. If a cell got too large, it would be more difficult to get oxygen in and waste products out. Volume increases faster than surface area.

Chromosomes Made up of DNA wrapped around proteins! Each cell of an organism has a specific number Ex. Fruit flies = 8 Ex. Austin Powers= 46 Ex. Carrots - 18

Chromosomes During cell division chromatin condenses into chromosomes. In order for each cell to get the right number the chromosomes have to double

Parts of a chromosome

Monday, 10/26/15 Learning Target: Know the phases of Cell Division. Learning Outcome: I will complete the “Mitosis Flipbook.”

The Cell Cycle Cell cycle – The series of events that cells go through as they grow and divide.

Interphase G1 – Growth phase #1. Cells increase in size and make new proteins and organelles. S – Synthesis. Chromosomes are replicated. G2 – Growth Phase #2 Cell division organelles are produced. Short phase.

Cell division Cell division is made up of 2 parts. 1. Mitosis – division of the nucleus. Divided into 4 phases. 2. Cytokinesis – division of the cytoplasm.

Prophase Chromosomes are visible. Centrioles separate Spindle fibers form Nuclear membrane breaks down.

Metaphase Chromosomes line up in the middle of the cell

Anaphase Chromosomes are pulled apart/away from each other.

Telophase The opposite of prophase occurs. Chromosomes disappear back to chromatin Nuclear membrane reforms Spindle fibers break apart and disappear

Cytokinesis Cytokinesis occurs right after Mitosis and is the division of the cytoplasm.

Can you tell the phase?

Cell Division Therefore, since cells can not become too large they need to divide into “daughter cells” To do this the DNA first copies itself so each daughter cell receives exact copies of the genetic info needed for the cell Also the ratio of surface area to volume increases which is a very good thing!

CELL CYCLE FLASHCARDS Identify the phases in the diagrams before cutting out. Cut out the diagrams. Glue diagrams to flashcards. On the back write the following: Phase of cell cycle What is occurring in the diagram.