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Warm Up. Do all living things grow and develop? Which type of cells have a nucleus? What information does the nucleus store? Do you think cells grow like we do? Explain why or why not. Agenda.
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Warm Up • Do all living things grow and develop? • Which type of cells have a nucleus? • What information does the nucleus store? • Do you think cells grow like we do? Explain why or why not.
Agenda • Objective: SWBAT: Explain what happens during the cell cycle and how the nucleus divides during mitosis AND determine the number of chromosomes a cell has following cellular division. • Go over quizzes • Mitosis cards • Mitosis Hand jive
Phase cards • Try to put the cards in order • What are the diagrams on the cards? • How did you decide what order to put them in? • What do you think is happening at the end of this process?
Unit 4 Mitosis and Meiosis… How things grow and develop!
1. How do we grow? a) The process starts with our cells • Our cells can only grow so big. Then they have to divide to produce more cells. • Example: When a fetus is developing and growing, it’s cells are dividing
What happens when a cell gets too big? If your mom got pregnant with sextuplets (meaning 6 babies at once!),the house would get REALLY crowded. Anyone would have a hard time taking care of all those kids!
2. What happens when a cell gets too big? a. When a cell is small, the information stored in that DNA is able to meet all of the cell’s needs. b. When a cell increases in size, the DNA has a harder time performing all of its functions.
3. What are Chromosomes? • Chromosomes are made up of DNA b. Every organism has a certain number of chromosomes • Example: Humans have 46 c. Most the time, you cannot see chromosomes because they are spread out in the nucleus • Chromosomes are only visible during cell division
3. What are chromosomes? d. Before a cell divides, it has to copy it’s genetic information. e. DNA is a type of nucleic acid that carries proteins and all the cell’s genetic information • DNA controls what a cell does • In Eukaryotic cells, DNA is stored in the nucleus f. DNA is bundled up into structures called chromosomes
4. What is the structure of a chromosome? • When they become visible, you can see that each chromosome is made up of two identical parts, called chromatids b. Each “sister” chromatid is connected in the center by a centromere
5. How does a cell divide? a. Cell Cycle: series of events that a cell goes through as it grows and divides b. Interphase is what happens in a cell before it divides. “Inter” means between, so interphase means between phases Step 1: The cell increases in size and makes new proteins and organelles Step 2: DNA is synthesized (copied) Step 3: The cell finishes everything it needs to do before it divides
5. How does a cell divide? c. One of the most important events is the “M” phase d. During the M phase, two things occur: • Mitosis: the division of a cell’s nucleus AND • Cytokinesis: the division of a cell • “Cyto” = cell • “kinesis”= movement
Watch a couple movies • Mitosis 1 • BrainPop Mitosis
Exit Ticket • What is a chromosome made of? • What must a cell do before it divides? • __________ is when the nucleus of a cell divides. • Why do cells divide? Explain in complete sentences.
Warm Up • How do we grow? • What happens to the DNA when a cell gets too big? • DNA is a type of ________________? • How many cells are produced after cytokinesis?
Agenda • Objectives: SWBAT: Identify the types of cells that undergo mitosis as well as the type of cells that undergo meiosis AND identify why approximately half of an individual’s DNA sequence comes from each parent. • Review Mitosis and learn about Meiosis • Mitosis Hand Jive • Go over quizzes • Exit Ticket
Review of Cell Division Before a cell becomes too large, it divides to form two “daughter” cells. What must a cell do before it can divide? Copy its DNA! What divides in the process of mitosis? The Nucleus
1. Mitosis • Mitosis is the division of a cell’s nucleus b. It’s a part of the M-phase of the Cell Cycle • The Cell Cycle: is the entire life span of a cell from creation to division • Before a cell can divide, it goes through the period of growth called Interphase. DNA is also copied
Review of Chromosomes: a. Each chromosome is a single, long structure that only becomes the “x” shape after DNA replication. b. A human has 23 pairs (46 total) chromosomes - After DNA is copied, we have 46 pairs (92 total!) chromosomes!!!!
Parent cell centrioles spindle fibers centrosome nucleus with DNA • During Interphase the cell prepares for mitosis and DNA is replicated
1. Prophase a. Prophase is the first phase of mitosis. • During Prophase the chromosomes bundle up and become visible. • The centrioles split up and take positions on opposite sides of the nucleus. • The nuclear envelope that surrounds the nucleus breaks down
2. Metaphase • Metaphase is the second stage of mitosis • During metaphase, chromosomes line up in the middle of the nucleus • The centrioles are on opposite sides of the nucleus and the spindle fibers attach to each chromosome
3. Anaphase a. Anaphase is the third phase of Mitosis. b. During Anaphase the chromosome pairs separate and move toward the opposite poles or sides of the cell.
4. Telophase • Telophase is the fourth and final phase of mitosis. • During Telophase the chromosomes begin to loosen and form bundles of material that are hard to see. • The cell membrane starts to pinch down and divide into two cells in Telophase. d. The nuclear envelope also reappears and begins to form around the two new nuclei.
5. Cytokinesis • Cytokinesis happens AFTER mitosis • This is when the cell’s cytoplasm divides to create two identical cells • After this process, each new cell will begin Interphase and the Cell Cycle will start all over again
Review • If a cell has 12 chromosomes, how many will it have after mitosis? • How many daughter cells are produced after mitosis? • What types of cells go through mitosis?
Sexual vs. Asexual Reproduction Do all organisms reproduce in the same way? No What type of organisms reproduce sexually? Animals and Plants What type of organisms reproduce asexually? Bacteria
All Living Things Reproduce*This is one of the 7 characteristics of living things* a. Most plants and animals reproduce by sexual reproduction. b. In sexual reproduction, cells from two different parents combine to form the first cell of the new organism.
What is Asexual Reproduction? a. Other organisms reproduce asexually, where a single parent produces offspring that are identical to the parent. b. What is Mitosis, asexual or sexual production? - Asexual. It’s one parent cell producing two identical cells from itself.
What organisms reproduce asexually? c. Most prokaryotes, like bacteria, reproduce asexually. d. Asexual reproduction is the primary form of reproduction for single-celled organisms such as bacteria.
What are diploid cells? a. Asexually Reproducing organisms have diploid cells. b. A diploid cell is a cell that has two copies of each chromosome. Diploid means two sets (2n) of chromosomes.
Exit Ticket • What happens in cytokinesis? • DNA is arranged in _______________. • If a cell has 4 chromosomes and goes through mitosis, how many chromosomes would it’s daughter cell have? • In asexual reproduction, offspring get their genetic information from ______________.
Warm Up • If a daughter cell has 23 pairs of chromosomes, how many pairs does the original cell have? What living thing has 23 pairs of chromosomes? • A ________ cell has two full sets of chromosomes. • What happens in asexual reproduction?
Agenda • Objectives: SWBAT: Explain that meiosis is necessary for sexual reproduction AND Determine the number of chromosomes a cell has following the process of meiosis. • Notes on Meiosis • Video and Questions • Exit Ticket
What are Haploid Cells? • Sex cells (eggs and sperm) contain only one copy of chromosomes. • Haploid means one set of chromosomes. A haploid cell is a cell that only has one set (1n) of genes. • Eggs have an X chromosome and sperm cells can have either an X or a Y chromosome.
