Warm up – 3-2-1 Countdown 3 – What are three differences between photosynthesis & respiration? 2 – What are two similarities between photosynthesis & respiration? 1 – What is the relationship between the two processes?
Warm up - Photosynthesis Identify the missing raw materials and products of photosynthesis: 4. 3. 1. 2. BrainPop Video - Photosynthesis
Cell Division
Cell Division Amoeba Sisters – Mitosis video WHY do cells divide (make more cells)? To grow To replace dead cells To repair damaged cells
Human Development So, the division of cells is how we become multicellular!
Cell Division/ Cell Cycle Asexual reproduction – reproduction involving one (or a) parent cell Cell division – a type of asexual reproduction where one cell divides and becomes two identical copies of itself. Mitosis – a special part of cell division where the nucleus of the cell makes a copy of itself and then divides into two new nuclei.
The Cell Cycle Foldable: Tape the blank papers in the format on the next page. Label each paper. Draw arrows. Write notes under each flap (from the PPT). Illustrate each step on the cover of each flap.
The Cell Cycle 1. Interphase 2a. Mitosis: Prophase 3. cytokinesis Pgs. 90-91 2d. Mitosis: Telophase 2b. Mitosis: Metaphase 2c. Mitosis: Anaphase
BrainPop video clip: Mitosis
1. Interphase Longest stage Cell grows Chromosomes are copied Chromatids – the two chromosome copies Centromere – region where chromatids are held together
Chromosomes
Mitosis - overview Mitosis – process of cell division that forms two new nuclei, each of which has the same number of chromosomes. 4 phases: Prophase Metaphase Anaphase Telophase
2a. Mitosis (Prophase) Prophase = chromosomes “pair” up with their copy. Prophase= chromosomes “pair” up with their copy. Chromosomes twist, coil & condense into an “X” shape Spindle fibers form Nuclear membrane begins to break down
2b. Mitosis (Metaphase) Nuclear membrane disappears Chromatid pairs line up in the middle of the cell metaphase = middle
2c. Mitosis (Anaphase) Chromatids separate Chromatids move apart to opposite sides of the cell anaphase = apart Cell becomes stretched
2d. Mitosis (Telophase) Two nuclear membranes form around each set of chromosomes telophase = two new nuclear membranes Mitosis is over
3. Cytokinesis Cell divides in two Cells without a cell wall (ex: animal cells): Cell pinches in two Cells with a cell wall (ex: plants): A cell plate forms between the two new cells
Demo of Mitosis See “Cells Alive” video/demo http://cellsalive.com/mitosis.htm
WARM UP: Which phase of the cell cycle? Interphase Telophase Anaphase Metaphase
Place the following Cell Cycle illustrations in order: B C E D F
Cell Cycle/Mitosis Review BrainPop - Mitosis
How many cells? How many chromosomes? (TOC #44) PARENT CELL Example: Human Skin Cell 46 Interphase – chromosomes are copied 92 Prophase - pair up Metaphase – middle Anaphase – apart Telophase – two nuclei Cytokinesis – cell splits in 2 46 46 DAUGHTER CELLS
Review Question: A cell with 10 chromosomes undergoes mitosis and cell division. How many daughter cells are produced and what number of chromosomes do they have? 2 daughter cells, 5 chromosomes each 1 daughter cell, 10 chromosomes each 4 daughter cells, 20 chromosomes each 2 daughter cells, 10 chromosomes each