1 Chapter 1 Plant Cells Overview  Earth’s primary producers  Nonmotile  Structure to catch light and sense gravity  Structure for transporting water and minerals, and photosynthetic products  Structure for adaptation

2 Figure 1.1 Schematic representation of the body of a typical dicot

3 Figure 1.1 Schematic representation of the body of a typical dicot (Part 1)

4 Figure 1.1 Schematic representation of the body of a typical dicot

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7 Figure 1.2 Primary and secondary cell walls and their relationship to the rest of the cell Because of their rigid cell walls, plant development depends solely on patterns of cell division and cell enlargement. Nearly all mitosis and cytokinesis occurs in meristems

8 Figure 1.3 Major tissue systems found in all plant organs Three major tissues Dermal tissue Ground tissue Vascular tissue

9 Figure 1.3 Major tissue systems found in all plant organs; (A,B) Dermal and ground tissue

10 Figure 1.3 Major tissue systems found in all plant organs; (C,D) Ground tissue

11 Figure 1.3 Major tissue systems found in all plant organs; (E) Vascular tissue

12 Figure 1.4 Diagrammatic representation of a plant cell

13 Figure 1.5 Membranes and phospholipids

14 Figure 1.5 Membranes and phospholipids; (A) Plasma membrane and endomembranes

15 Figure 1.5 Membranes and phospholipids; (B) Anchored membrane proteins Plastid membrane

16 Plant cell organelles Plant cells contain compartments derived from the endomembrane system. Chloroplast and mitochondria are not derived from the endomembrane system. Endomembrane system plays a central role in secretory process, membrane cycling, and the cell cycle. The composition and fluid-mosaic structure of the plasma membrane permits regulation of transport into and out of the cell.

17 Figure 1.6 (A) Nucleolus and nuclear envelope; (B) Nuclear pore complexes (NPCs) Nuclear pore complexes

18 Nucleus The nucleus is the site of storage, replication, and transcription of the chromatin, as well as being the site for the synthesis of ribosomes

19 Figure 1.7 Packaging of DNA in a metaphase chromosome

20 Figure 1.7 Packaging of DNA in a metaphase chromosome (Part 1)

21 Figure 1.7 Packaging of DNA in a metaphase chromosome (Part 2)

22 Figure 1.8 Basic steps in gene expression

23 Figure 1.8 Basic steps in gene expression (Part 1)

24 Figure 1.8 Basic steps in gene expression (Part 2)

25 Figure 1.8 Basic steps in gene expression (Part 3)

26 Figure 1.10 The endoplasmic reticulum ER is a system of membrane-bound tubules that form a complex and dynamic structure Rough ER is involved in protein synthesis, smooth ER is the site of lipid biosynthesis ER provides membrane and internal cargo for other compartments of the endomembrane system

27 Figure 1.11 Electron micrograph of Golgi apparatus in a tobacco root cap cell

28 Figure 1.12 Vesicular traffic along the secretory and endocytotic pathways

29 Figure 1.13 Clathrin-coated pits are associated with secretion of slime in corn root cap Secretion of proteins from cells begins with the RER During endocytosis, membrane is removed from the plasma membrane by formation of small clathrin-coated vesicles Endocytosis from the plasma membrane provides membrane recycling

30 Figure 1.14 (A) Electron micrograph of an oil body; (B) Diagram of the formation of oil bodies Oil bodies, peroxisomes, and glyoxysomes grow and proliferate independently of the endomembrane system

31 Figure 1.16 (A) Mitochondrion; (B) Mitochondria from a leaf cell of Bermuda grass

32 Figure 1.17 Chloroplasts

33 Figure 1.17 Chloroplasts; (A) Electron micrograph of a chloroplast from timothy grass

34 Figure 1.17 Chloroplasts; (B) The same chloroplast at higher magnification

35 Figure 1.20 (A) Microtubule in longitudinal view; (B) Representation of a microfilament Plant cytoskeleton: microtubules and microfilaments

36 Figure 1.21 Dynamic equilibrium between microtubule polymerization and depolymerization

37 Figure 1.22 Myosin-driven movement of organelles

38 cytoskeleton  A three-dimensional network of microtubules and microfilaments organizes the cytosol  Microtubules and microfilaments can assemble and disassemble  Molecular motors associated with components of the cytoskeleton move organelles throughout the cytoplasm  During cytoplasm streaming, interaction of the F- actin with myosin provides for independent movement of organelles, including chloroplasts

39 Figure 1.23 Cell cycle in a vacuolated cell type Cell cycle regulation

40 Figure 1.24 The structure of a metaphase chromosome

41 Figure 1.25 Changes in cellular organization that accompany mitosis

42 Figure 1.26 Changes in the organization of the phragmoplast and ER during cell plate formation

43 Figure 1.27 Plasmodesmata between cells

44 Summary Plasmodesmata tubular extensions of the plasma membrane traverse the cell wall and connect the cytoplasms of the clonally derived cells, allowing water and small molecules to move between cells without crossing a membrane