Plant Physiology Quiz 2 Study Guide PDF

**Plant Physiology Quiz 2 Study Guide** **Chapter 3: The Plant Cell and the Cell Cycle** 1. Structure of prokaryotic cell differ from eukaryotic cell because prokaryotic cells are don't have nucleus (their DNA is not surrounded by a membranous envelope). They have nucleoid which conta...

**Plant Physiology Quiz 2 Study Guide** **Chapter 3: The Plant Cell and the Cell Cycle** 1. Structure of prokaryotic cell differ from eukaryotic cell because prokaryotic cells are don't have nucleus (their DNA is not surrounded by a membranous envelope). They have nucleoid which contains the DNA. But eukaryotic cell has nucleus. Archaea and bacteria have prokaryotic cells. Most prokaryotic cells have one chromosome. Prokaryotic cells lake specialized membrane bounded structures(organelles) that perform specific functions. In eukaryotic cells, the chromosomes are surrounded by an envelope, made up of two membranes, which separates them from the other cell contents. The DNA in eukaryotic cells is linear and tightly bound to special proteins known as histones, forming several chromosomes that are structured more complex than bacteria chromosomes. Eukaryotic cells go through cell division that perform different functions. - E. coli is an example of a prokaryote, and it has cell wall, a plasma membrane, and cytoplasm. The DNA is found in the nucleoid which is in the center of each cell but is not surrounded by a membrane. 2. Plastids are characteristic components of plant cells, and they are concerned with such processes as photosynthesis and storage. The principle types of plastids are: 1. Chloroplasts, chromoplasts, and leucoplasts. Each are surrounded by envelope of two membranes. - Chloroplasts are the sites of photosynthesis, it contains chlorophylls and carotenoid pigments. The chlorophyll pigments are responsible for the green color of these plastids. The carotenoids are yellow and orange pigments that, in green leaves, are masked by the more numerous chlorophyll pigments. Chloroplasts are found in plants and green algae. - Chromoplasts are also pigmented plastids. Of variable shape, chromoplasts lack chlorophyll but synthesize and retain carotenoid pigments, which are often responsible for the yellow, orange, or red colors of may flowers, aging leaves, some fruits, and some roots, such as carrots. - Leucoplasts lack pigments and an elaborate system of inner membranes. Some leucoplasts, known as amyloplasts, synthesize starch, whereas others are thought to be capable of forming a variety of substances, including oils and proteins. 3. The endoplasmic reticulum is the initial source of membranes. Transition vesicles from the endoplasmic reticulum transport new membrane material to the Golgi apparatus, and secretory vesicles derived from the trans-Golgi network contribute to the plasma membrane. The trans-Golgi network also supplies vesicles that fuse with the tonoplast and thus contribute to formation of the vacuoles. The endoplasmic reticulum, Golgi apparatus, and trans-Golgi network, therefore, may be considered a functional unit in which the Golgi bodies serve as the main vehicles for the transformation of endoplasmic-reticulum-like membranes into plasma-membranelike and tonoplast-like membranes. 4. The cytoskeleton of the cell is a dynamic three-dimensional network of protein filaments (microtubules and actin) that extends throughout the cytosol and is intimately involved in many processes. These processes include: 1. Cell division, 2. Growth, 3. Differentiation, 4. Movement of organelles from one location to another within the cell. 5. Primary wall are the first wall layers to form. It contains primary pit-fields. Found in actively dividing and actively metabolizing cells. Secondary wall are formed in some cells after the primary wall is laid down. Located interior to the primary wall. Contains pits. Found in cells with strengthening and/or waterwall is laid down. Located interior to conducting functions. Is rigid and thus imparts added strength. End of chapter questions: 1. Cell theory is the theory that everything alive has cell membrane. The significance of this theory for biology is that in order for us to study life we need to know what is the basic unit of life, which is the cell. 2. Three features of plant cells that distinguish them from animal cells are: 1. Plant cell walls are made of cellulose 2. Plant cells have chloroplasts( where photosynthesis happens) 3. Have larger Vacuoles. 3. Plastids and mitochondria are said to be "semi-autonomous" organelles because both have their own DNA, ribosomes, and can make their own proteins. 4. Vacuoles are important storage compartments for primary metabolites, such as sugars and chlorophyll. Vacuoles are also involved in the breakdown of macromolecules and the recycling of their components within the cell. 5. The phenomenon of autumn leaf coloration happens because the leaves lose the ability to synthesize chlorophyll due to the shortened sunlight and drop of temperature which makes the colors of the leaf go from green to yellow/ orange. 6. Rough ER is complex, three-dimensional membrane system that spreads throughout the entire cytosol. Cells that store proteins have abundant rough ER, which consists of flattened sacs, or cisternae, with numerous polysomes on their outer surface. Whereas the cells that produce and release lipids have smooth ER, which lacks ribosomes and is largely tubular in form. 7. Microtubules are thin, cylindrical structures of 24 nanometers in diameter and varying lengths, they are composed of subunits of the protein tubulin. They cause cell division, the growth of the cell wall, and the movement of flagella. Actin filaments composed of actin protein. Has filaments of 5 to 7 nanometers in diameter. The main function of Actin filaments is cytoplasmic steaming. **Chapter 4: The Movement of substances into and out of Cells** 1. Water potential is the potential energy of water. Water moves from a region of higher water potential to one of lower water potential. The concept of water potential is useful because it allows plant physiologists to predict how water will move in the plant under various conditions.