Cell Theory and Homeostasis SC.6.L.14.2 Investigate and explain the components of the scientific theory of cells (cell theory): all organisms are composed of cells (single-celled or multicellular), all cells come from preexisting cells, and cells are the basic unit of life. Essential Question: What processes take place within all cells in order to maintain homeostasis?

Bell Ringer During cellular respiration, cells break down sugars to release energy. In this process, water and carbon dioxide are produced as waste products. What must happen to these waste products in order for a cell to maintain homeostasis? They must be excreted from the cell. They must be used for photosynthesis. They must be digested and used as food. They must be permanently stored inside the cell.

I Do: Guided Notes

THE CELL THEORY The Cell Theory states: All organisms are composed of cells. Cells are the basic units of life. Cells only come from preexisting cells.

Homeostasis In order for cells to function properly, conditions inside the cell must stay constant even if outside factors change. Cells must keep the correct amount of nutrients and water and remove wastes. The cell membrane will allow some things to pass through while blocking other things.

Cell Processes & Homeostasis Getting rid of waste Extracting energy from food Cell Reproduction

RELEASING ENERGY FOR LIFE CELLULAR RESPIRATION RELEASING ENERGY FOR LIFE Glucose stores chemical energy that is released. The mitochondria breaks down glucose for energy.

GETTING RID OF WASTE Cells need to get rid of waste in order to maintain homeostasis. Wastes may include carbon dioxide, water, and salt. Nutrients can be easily taken in and eliminated. Taken in and elimination are hugely affected.

REPRODUCTION Cells must be able to reproduce quickly and easily. The process of cell division is known as MITOSIS. One cell divides into two new cells with a full set of DNA for growth and repair.

RESPONDING TO THE ENVIRONMENT Living things must work to maintain homeostasis in a constantly changing environment. Our body temperature must be 98.6°F in order to be in homeostasis. When hot, you may sweat so that the evaporation can cool you. When cold, you may shiver to create heat. 10

Homeostasis A C B What processes of cellular homeostasis are represented by the images above? Explain why those processes are important. A- Making copies of cells. B- Getting nutrition from food C-Getting rid of waste SC.6.L.14.3

We Do Collaborative Activity Teachers may need to facilitate the concept map.

Revisiting the Bell Ringer During cellular respiration, cells break down sugars to release energy. In this process, water and carbon dioxide are produced as waste products. What must happen to these waste products in order for a cell to maintain homeostasis? They must be excreted from the cell.* They must be used for photosynthesis. They must be digested and used as food. They must be permanently stored inside the cell.

YOU DO TIME!

You Do Question #1 The number of cells in three separate Petri Dishes was recorded over a period of 20 days. The data shown in the table best illustrates which part of the cell theory? All living things are made up of cells. Cells are the basic unit of living things. Organisms can be single celled or many celled. All cells come from preexisting cells. CORRECT ANSWER: D

You Do Question #2 Organs are made up of vast numbers of cells that perform various tasks. When cells die within an organ, homeostasis is interrupted. What will most likely happen so that homeostasis can be maintained?   The organ will continue to work, but with decreased function. The organ will immediately shut down so that no further damage will occur. The remaining cells will be unable to divide and the organ will quit working. The remaining cells will reproduce in order to replace the ones that have died. CORRECT ANSWER: D

You Do Question #3   The cell membrane regulates the amount of water and other molecules as they pass into or out of the cell. What is this balance between the water on the inside and outside of the cell called?   Regulation Homeostasis Turgor Pressure Hydrological Stability CORRECT ANSWER: B

EXIT TICKET (Closing): What processes take place within all cells in order to maintain homeostasis?