Opening Activity: April 16, 2018 Pick up two handouts at front: Unit Review, NB Checklist & Idea Journal. FLASH Parent Letter – Take home to share! Find your colored chromosome (pink/green/yellow) – I will stamp! What cells in your body divided over the break? What happened before your cells divided? Why? I can… Explain how cells can have the same DNA but have different functions. Homework: Planaria Explanation Due 4/18 Development Test –Thurs 4/19 Unit Review page due Thurs 4/19 Development NB Due Mon 4/23

DNA Replication Review DNA Splits in half New nucleotides come in and pair up on each half Final product is two IDENTICAL strands of DNA Why do cells want two identical strands of DNA?

The right gene at the right time Cell Differentiation The right gene at the right time

Key Questions… How do cells know what type of cell to become? How do they coordinate to form tissues, organs, and a complete organism?

Cell Differentiation Activity Read the introduction to the activity. Review your chromosome to be sure you colored it correctly. Check your neighbor!! Form a group with all 4 cell types – bone, muscle, stomach and skin. Write their names on your paper. Work together as a group of 4 to review the cells and answer the analysis questions. STAMP!!

HOMEWORK IDEA JOURNAL: Complete Cell Division and DNA Replication grids on your Idea Journal – Due Tuesday April 17

Opening Activity: April 17, 2018 Have first two rows on Idea Journal ready to stamp. From yesterday’s work…. Identify one gene that is found in all cells. Why do you think ALL cells expressed the gene? What gene is expressed in a skin cell but NOT a muscle cell? I can… Explain how cells can have the same DNA but have different functions. Use data to describe what happened planaria. Homework: Planaria Explanation Due 4/18 Development Test –Thurs 4/19 Unit Review page due Thurs 4/19 Development NB Due Mon 4/23

What makes the different types of cells in your body unique? Muscle cells and neurons in your body have the same DNA, but they express (use) different genes. Gene expression causes cells to look unique and to perform different functions.

Stem Cells vs. Differentiated Cells Differentiated cell = Specialized cell (neuron, muscle) Stem cells are cells that have not yet differentiated into a specific cell type. Stems cells can be turned into differentiated cells by turning on and off particular genes.

When do cells differentiate? During development (embryonic stem cells) Zygote to embryo to fetus to infant Over your life as cells are replenished (adult stem cells) Examples: Blood cells are replenished Intestinal cells are shed and replaced

Development and Differentiation Key questions: How do cells know what type of cell to become? How do they coordinate to form tissues, organs, and a complete organism? Answer: Cells must communicate through signals to coordinate development.

Planaria Wrap up Take final measurements and observations. Record data and observations in journal. Calculate changes in length over last 3 weeks. Record data on class data table. Return Planaria to the “Recovery Container”. Return petri dishes to front tub.

Example: Body plan formation (head vs. tail) Cells develop differently in the head and the tail, and in other positions of the planaria’s body Communication between cells is important in multicellular organisms for body pattern formation

We can use a model organism to study these questions!

Opening Activity: April 18, 2018 I will stamp your “Development Reflection”. At what time of your life do cells differentiate (go through a process to become different type of cells)? How are specific genes turned on/off in a cell? How are genes turning on in our cell related to traits a specific cell would have? I can… Use data to describe what happened planaria. Homework: Planaria Explanation Due 4/18 Development Test –Thurs 4/19 Unit Review page due Thurs 4/19 Development NB Due Mon 4/23

When do cells differentiate? During development (embryonic stem cells) Zygote to embryo to fetus to infant Over your life as cells are replenished (adult stem cells) Examples: Blood cells are replenished Intestinal cells are shed and replaced

Goals Today Work on Planaria Explanation – DUE TODAY!! Work on Idea Journal/Review Sheet and Notebook Study with a partner using the QUIZLET online at our class website.