Transcript Cells Unit
Cells Unit Learning Goal 5: Explain the process of cell reproduction in both prokaryotic and eukaryotic cells. Cell Division in Eukaryotes Cells Must Be Small Cells must divide because if they grew too large their DNA could not keep up with demands and materials could not efficiently be distributed. Section 10-1 Cell Size Surface Area (length x width x 6) Volume (length x width x height) Ratio of Surface Area to Volume Ratio of Surface Area to Volume in Cells Chromosomes Carries the genetic information from one generation to another. Not visible in most cells except during cell division. Uncoils into chromatin. Chromosomes are replicated before cell division. Each chromosome consists of identical “sister” chromatids. Cell Cycle The series of events that occur during the life of the cell. Cell grows Prepares for division Cell divides Section 10-2 Figure 10–4 The Cell Cycle G1 phase M phase S phase G2 phase Section 10-2 Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Nuclear envelope Chromatin Interphase Centromere Chromosomes (paired chromatids) Prophase Cytokinesis Spindle Centriole Telophase Nuclear envelope reforming Centriole Individual chromosomes Anaphase Metaphase Interphase G1 phase Cell Growth S phase DNA Replication Chromosomes are copied. G2 phase Preparation for Mitosis Organelles and other molecules required for cell division are produced. Mitosis Nuclear Division Divided into four phases Prophase Metaphase Anaphase Telophase Section 10-2 Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Nuclear envelope Chromatin Interphase Centromere Chromosomes (paired chromatids) Prophase Cytokinesis Spindle Centriole Telophase Nuclear envelope reforming Centriole Individual chromosomes Anaphase Metaphase Prophase Chromosomes become visible. Centrioles move to the poles. Spindles begin to form. Nuclear envelope breaks down. Section 10-2 Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Nuclear envelope Chromatin Interphase Centromere Chromosomes (paired chromatids) Prophase Cytokinesis Spindle Centriole Telophase Nuclear envelope reforming Centriole Individual chromosomes Anaphase Metaphase Metaphase Chromosomes line up in the middle of the cell. Chromosomes connect to spindles. Section 10-2 Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Nuclear envelope Chromatin Interphase Centromere Chromosomes (paired chromatids) Prophase Cytokinesis Spindle Centriole Telophase Nuclear envelope reforming Centriole Individual chromosomes Anaphase Metaphase Anaphase Sister chromatids separate and move toward the poles. Section 10-2 Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Nuclear envelope Chromatin Interphase Centromere Chromosomes (paired chromatids) Prophase Cytokinesis Spindle Centriole Telophase Nuclear envelope reforming Centriole Individual chromosomes Anaphase Metaphase Telophase Chromosomes uncoil. New nuclear envelopes forms around each new set of chromosomes. Concept Map Section 10-2 Cell Cycle includes G1 phase Interphase M phase (Mitosis) is divided into is divided into S phase G2 phase Prophase Metaphase Anaphase Telophase Cytokinesis Splitting of the cytoplasm. Plant cells form a cell plate that eventually becomes the cell wall. Animal cells pinch the cell membrane together until the cytoplasm is pinched into two nearly equal parts. Section 10-2 Figure 10–5 Mitosis and Cytokinesis Spindle forming Centrioles Nuclear envelope Chromatin Interphase Centromere Chromosomes (paired chromatids) Prophase Cytokinesis Spindle Centriole Telophase Nuclear envelope reforming Centriole Individual chromosomes Anaphase Metaphase Cell Division in Prokaryotic Cells Binary Fission – Asexual reproduction in which circular bacterial DNA replicates then cell divides. Control of Cell Division Section 10-3 Section 10-3 Figure 10–8 Effect of Cyclins The sample is injected into a second cell in G2 of interphase. A sample of cytoplasm is removed from a cell in mitosis. As a result, the second cell enters mitosis. Cancer Uncontrolled cell growth. Cancer cells do not respond to the signals that regulate the growth of most cells. Form masses of cells called tumors.