Ch 10 The Cell Cycle

Chapter 10.1 Cell Growth Do Now 1/19: Do we grow because our cells are larger or because we have more of them? Explain your reasoning. Do we grow because our cells are larger or because we have more of them? Explain your reasoning. Take out 10 vocab hw Take out 10 vocab hw

I. Why should cells divide? 1. DNA overload a. There is only one original copy of DNA in each cell b. If the cell gets too big, the DNA can not serve it. c. A small library can only serve a small town. More people = the library needs more books

2. Exchanging Materials a. Food, O 2, H 2 O into a cell, CO 2 and waste out through the cell membrane b. If the cell is too big, not enough nutrients will be moved in and too much waste will build up. c.There would not be enough surface area for the increasing volume

3. Surface Area to Volume Ratio a. Volume increases more rapidly than the surface area. Surface area = (length x width)(number of sides) Volume = length x width x height Surface area/volume = ratio

Figure it out…

Exit Card Why is it important for cells to remain small? sf10/unit3/surfacearea.htmlhttp:// sf10/unit3/surfacearea.html EOKNxN8https:// EOKNxN8

Do Now 1/19 Explain why cells must divide when they get too large (Give at least 2 reasons). Take out vocab.

That first cell had all the information and instructions to make you as you are now. It was all in a secret code in the middle of the cell. This code is called DNA. It is a very long list of instructions that gives each cell in your body its own shape and function.

That first cell grew a little and then "wiggly" bits called chromosomes could clearly be seen. Half of the chromosomes came from the egg cell, and half from the sperm cell and each chromosome contained two copies of that secret code, the plans to make yousecret code The first cell then divided into two separate cells using a process called cell division and this is how it happened...

First the chromosomes lined up in the center of the cell.

Then each chromosome split into two identical halves.

Next the cell made a fold down its middle and...

HEY PRESTO!!! Two cells, which both had all the information and instructions to make you...and then...

Those cells grew a bit... copied their chromosomes and those became then became then became then then then

Then: You get the idea…

Very soon there were

If one of your cells was really this size you'd be as big as the Empire State Building in America.Empire State Building

II. Cell Division A. Before the cell becomes too large: 1. It copies (replicates) it’s DNA 2. Divides into 2 equal and identical daughter cells

III. The Cell Cycle Happens in stages: 1. Interphase: Divided into three phases A. G 1 B. S phase C. G 2 2. Mitosis/Cytokinesis A Cell spends the most time here!

Inter- Phase Blue Red Yellow orange

IV. Interphase A. Divided into 3 phases: 1. Gap 1 (G 1 )-cell grows in size 2. Synthesis (S)–DNA replicated (synthesized) 3. Gap 2 (G 2 )–prepares for division

Interphase

Inter- Phase Blue Red Yellow orange

V. Mitosis Divided into 4 phases: 1. prophase, metaphase, anaphase, and telophase Mitosis= - DNA in the form of chromosomes separate into 2 identical halves.

Inter- Phase Blue Red Yellow orange

VI. Cytokinesis A.Cytoplasm pinches in and separates forming 2 identical cells B.Proteins like Cyclins control cell division! –Mitosis is used in multi-cellular organisms for the division of somatic cells (body cells) – ZQkmooyPkhttps:// ZQkmooyPk

VII. Chromosomes A. Made of DNA and proteins B. Invisible except during cell division (chromatin  chromosomes) C. Human cells have 46 carrot cells have 18

Exit Card Explain why it would be detrimental to an organism if chromosomes were not replicated prior to mitosis.

ll_cycle/cells3.html hill.com/sites/ /student_view0/chapter11/animations.htmlhighered.mcgraw- hill.com/sites/ /student_view0/chapter11/animations.html