1 / 25

8.1 and 8.2 Notes Chromosomes and Cell Cycle

8.1 and 8.2 Notes Chromosomes and Cell Cycle. Essential Question How does the cell cycle regulate cell division?. Standard. B-4.2 Summarize the relationship between DNA, genes, and chromosomes.

lan
Download Presentation

8.1 and 8.2 Notes Chromosomes and Cell Cycle

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. 8.1 and 8.2 NotesChromosomes and Cell Cycle Essential Question How does the cell cycle regulate cell division? 8.1-8.2 notes

  2. Standard • B-4.2 Summarize the relationship between DNA, genes, and chromosomes. • B-2.6 Summarize characteristics of the cell cycle: interphase (G1, S, G2) and mitosis (prophase, metaphase, anaphase, telophase); cytokinesis. 8.1-8.2 notes

  3. Chromosome Structure • Chromosomes are rod-shaped structures made of DNA and proteins • Each chromosome is a single DNA molecule associated with proteins • The DNA in eukaryotic cells wraps tightly around proteins called histones. • Histones help maintain the shape of chromosomes and aid in the tight packing of DNA • A chromosome consists of two identical halves called sister chromatids. • When the cell divides, each of the two cells receives one chromatid from each chromosome. • Two chromatids are attached at the central point called a centromere. • The centromere holds the two chromatids together until they separate during cell division. 8.1-8.2 notes

  4. Section 1 Chromosomes Chapter 8 Chromosome Structure 8.1-8.2 notes

  5. DNA andhistones SupercoiledDNA DNA doublehelix Chromatin Chromosomes condense at the start of mitosis. • DNA wraps around proteins (histones) that condense it. 8.1-8.2 notes

  6. Cell Division in Prokaryotes • Prokaryotes have cell walls but lack nuclei and membrane-bound organelles. • A prokaryote’s single DNA molecule is not coiled around proteins to form chromosomes. • A prokaryotes DNA is circular chromosome attached to the inner surface of the plasma membrane. • Prokaryotes divided by a process called binaryfission. 8.1-8.2 notes

  7. Cell Division in Eukaryotes • In eukaryotic cell division, both the cytoplasm and the nucleus divide. • The are two kinds of cell division: • Mitosis – cell division that results in new cells with genetic material that is identical to the original cell • Meiosis – cell division that results in haploid cells that are genetically different from the parent cell. It occurs in gametes or sex cells. • Mitosis is asexual meaning that it produces offspring from one parent. • All cells except sex cells reproduce by mitosis. 8.1-8.2 notes

  8. The Cell Cycle • Cell Cycle • The cell cycle is the repeating set of events in the life of a cell. • The cell cycle consists of cell division and interphase. • Cell division in eukaryotes includes nuclear division, called mitosis, and the division of cytoplasm, called cytokinesis. 8.1-8.2 notes

  9. Cell Cycle – Three Parts • Interphase consists of growth (G1), DNA replication, and preparation for cell division (G2). • G1 – period of growth and development • S – DNA is copied (replicated) • G2 – cell prepares to divide • Mitosis – division of the cell nucleus • Prophase – chromosomes condense and nuclear envelope dissolves • Metaphase – chromosomes line up at equator • Anaphase – chromosomes separate and move to the poles • Telophase – chromosomes arrive at the poles • Cytokinesis – division of the cytoplasm 8.1-8.2 notes

  10. Interphase • Cells spend most of the cell cycle in interphase. • Following cell division, offspring cells are approximately half the size of the original cell. • During the first stage – G1 phase – offspring cells grow to mature size. • Once cells have reached a mature size, they can enter the S (synthesis) phase. • During the S phase, the DNA is copied (synthesized) • The G2 phase represents the gap between DNA synthesis (S phase) and preceding cell division. • The G2 phase is a time when the cell prepares for cell division. • Cells that exit the cell cycle do not copy their DNA and are said to be in the G0 phase. 8.1-8.2 notes

  11. Parent cell centrioles centrosome Interphase • Interphase prepares the cell to divide. spindle fibers nucleus with DNA 8.1-8.2 notes

  12. Plant Cells in Interphase 8.1-8.2 notes

  13. Prophase • DNA shortens and coils into rod-shaped chromosomes. • Nuclear membrane and nucleolus break down and disappear. • Centrosomes containing centrioles move toward opposite poles of the cell. • Array of spindle fibers called the mitotic spindle begins to form. 8.1-8.2 notes

  14. Metaphase • Centrioles move to the poles • Spindle fibers attach to the centromere of chromosome • Chromosomes line up at the equator (middle) of cell 8.1-8.2 notes

  15. 8.1-8.2 notes

  16. Anaphase • During anaphase, sister chromatids separate to opposite sides of the cell. 8.1-8.2 notes

  17. 8.1-8.2 notes

  18. Telophase • During telophase, the new nuclei form • chromosomes begin to uncoil. • Often called reverse prophase because the opposite happens as the cell goes back to normal. 8.1-8.2 notes

  19. 8.1-8.2 notes

  20. Cytokinesis • Cytokines is when the cytoplasm divides • Cytokinesis differs in animal and plant cells. • Plant cells form a new cell plate that splits the cell and animals cells form a cleavage furrow. 8.1-8.2 notes

  21. Plant cell Mitosis 8.1-8.2 notes

  22. 8.1-8.2 notes

  23. 8.1-8.2 notes

  24. 8.1-8.2 notes

  25. Control of the Cell Cycle • Checkpoints are times when the cell stops to check and make sure that mitosis is proceeding normally. • G1 checkpoint (cell growth) – • proteins check to see if the cell is healthy and ready to divide. • Healthy cells proceed to the S phase • DNA synthesis (G2) checkpoint • DNA repairs enzymes and checks the results of replication • If ok, then the cell enters mitosis • Mitosis checkpoint • Proteins signal the cell to exit mitosis • Cell then enter G1 phase and the process starts over. 8.1-8.2 notes

More Related