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what is the function of collenchyma tissue

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Answers:Three tissue systems in plants: 1. Ground contains three types of tissues: parenchyma, collenchyma and sclerenchyma 2. Vascular - consists of xylem and phloem tissues 3. Dermal - consists of epidermis which may later be replaced by periderm Tissue types: 1. Parenchyma - is the progenitor of all other tissues and the most common component of ground tissues. It is composed of parenchyma cells which perform virtually all the metabolic activities of plant cells a. Parenchyma cells are living at maturity, polyhedral (many sided) shaped and capable of cell division b. In the primary plant body they occur as continuous masses in the cortex of roots, stems, piths of stems and roots, and leaf mesophyll. They may also occur as vertical strands of cells in vascular tissues and also as horizontal strands (rays) in secondary vascular tissues c. Some may have secondary walls d. Those with only primary walls play an important role in regeneration and wound healing. They may be lignified, suberized or cutinized 2. Collenchyma - composed of collenchyma cells which are living at maturity a. They usually occur as discrete strands or as continuous cylinders beneath the epidermis in stems and petioles (e.g. celery). They also border veins in dicots b. Collenchyma cells are relatively long, with nonlignified primary walls which allows them to stretch c. Collenchyma cells commonly have unevenly thickened cell walls d. They provide support, largely for the primary plant body 3. Sclerenchyma - composed of sclerenchyma cells which are non-living and lack protoplasts at maturity a. Sclerenchyma cells may be found in all parts of both the primary and secondary plant body b. They have thick, lignified secondary walls. They provide strength and support in parts that have ceased elongating c. There are two type of sclerenchyma cells: i) Fibers - long slender cells which occur in strands or bundles, e.g. hemp, flax and jute. They provide support and some storage ii) Sclerids - variable in shape, often branched, may occur singly or in groups in ground tissues throughout the plant. They make up the seed coat of seeds, shells of nuts, stones of drupes, and give the pear its gritty texture. Their function is primarily for protection. 4. Epidermis - the outermost layer of the primary plant body covering leaves, floral parts, fruits, seeds, stems and roots (until they undergo secondary growth). a. The epidermis is generally only one layer thick b. The epidermis is composed mostly of unspecialized cells, either parenchyma and/or sclerenchyma c. The epidermis of leaves often contain trichomes, various types of hairs d. Guard cells which form stomata, pores for gas exchange, are also present on one or both surfaces

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Answers:A. Tissues are groups of cells that are structurally and/or functionally distinct. Tissues are further arranged to form tissue systems, which are initiated during the development of the embryo by the ground meristem, procambium and protoderm B. Three tissue systems in plants: 1. Ground contains three types of tissues: parenchyma, collenchyma and sclerenchyma 2. Vascular - consists of xylem and phloem tissues 3. Dermal - consists of epidermis which may later be replaced by periderm C. Tissue types: 1. Parenchyma - is the progenitor of all other tissues and the most common component of ground tissues. It is composed of parenchyma cells which perform virtually all the metabolic activities of plant cells a. Parenchyma cells are living at maturity, polyhedral (many sided) shaped and capable of cell division b. In the primary plant body they occur as continuous masses in the cortex of roots, stems, piths of stems and roots, and leaf mesophyll. They may also occur as vertical strands of cells in vascular tissues and also as horizontal strands (rays) in secondary vascular tissues c. Some may have secondary walls d. Those with only primary walls play an important role in regeneration and wound healing. They may be lignified, suberized or cutinized 2. Collenchyma - composed of collenchyma cells which are living at maturity a. They usually occur as discrete strands or as continuous cylinders beneath the epidermis in stems and petioles (e.g. celery). They also border veins in dicots b. Collenchyma cells are relatively long, with nonlignified primary walls which allows them to stretch c. Collenchyma cells commonly have unevenly thickened cell walls d. They provide support, largely for the primary plant body 3. Sclerenchyma - composed of sclerenchyma cells which are non-living and lack protoplasts at maturity a. Sclerenchyma cells may be found in all parts of both the primary and secondary plant body b. They have thick, lignified secondary walls. They provide strength and support in parts that have ceased elongating c. There are two type of sclerenchyma cells: 1) Fibers - long slender cells which occur in strands or bundles, e.g. hemp, flax and jute. They provide support and some storage 2) Sclerids - variable in shape, often branched, may occur singly or in groups in ground tissues throughout the plant. They make up the seed coat of seeds, shells of nuts, stones of drupes, and give the pear its gritty texture. Their function is primarily for protection 4. Xylem - principle water conducting tissues in vascular plants. May be primary or secondary in origin a. The principal conducting cells are called tracheary elements b. They are elongated cells which are dead at maturity c. Two types of tracheary elements: 1) Tracheids - generally long and thin, may have pits in their walls but they have imperforate end walls. They occur in the seedless vascular plants, gymnosperms and some primitive angiosperms 2) Vessel members - elongated shape but not as long or thin as tracheids. They have perforate end walls. Vessel members are joined together into long tubes called vessels. Occur primarily in the angiosperms 5. Phloem - collective term for the principle food conducting tissue in vascular plants. The individual cells are called sieve elements. Sieve refers to clusters of pores called sieve areas, through which the protoplasts of adjacent sieve elements are interconnected a. Sieve elements are living at maturity but they either completely lack nuclei or they contain only remnants of them. b. At maturity the tonoplast of the vacuole disappears so that there is no differentiation between the cytoplasmic and vacuolar contents. The remaining elements of the protoplast (plasma membrane, plastids, smooth ER, mitochondria) are distributed along the cell walls. There are no ribosomes, dictyosomes, or nuclei c. Sieve tube members are usually associated with parenchyma cells called companion cells which are complete living cells connected to them via numerous plasmodesmata. The companion cells perform many of the metabolic activities for the sieve tube members d. There are two types of sieve elements: 1) Sieve cells - have narrow pores, no sieve plates. They occur in most seedless vascular plants and in gymnosperms 2) Sieve tube members - have large pores on sieve plates, usually on end walls. Sieve tube members are stacked end to end to form sieve tubes. They occur only in angiosperms 6. Epidermis - the outermost layer of the primary plant body covering leaves, floral parts, fruits, seeds, stems and roots (until they undergo secondary growth). a. The epidermis is generally only one layer thick b. The epidermis is composed mostly of unspecialized cells, either parenchyma and/or sclerenchyma c. The epidermis of leaves often contain trichomes, various types of hairs d. Guard cells which form stomata, pores for gas exchange, a

Question:

Answers:1. Insulation of body from cold 2. store extra energy to use by the body when needed 3. ushening effect on vicera of the body to be protected from jerks

Question:A.) allow exchange of carbon dioxide and oxygen B.) permit growth of stems and roots C.) transport sugar and water D.) attract pollinators to a plant

Answers:B.

From Youtube

Four Categories of Tissues in the Body :The 4 categories of body tissues--Epithelial, Connective, Muscle, and Nerve--are described in this video, which was made in Dr. O's A&P1 class. Make sure you answer & review the questions at the end of the video, and also the following questions: 1.What is the structure, function & location of each type of epithelial tissue (ie, squamous, cuboidal, columnar, pseudostratified, & stratified)? 2.What does pseudostratified mean? 3.Describe the location, function, and characteristics of the types of connective tissue. 4. What are neurons and neuroglia? 5.What are sensory and motor neurons? 6.For each of the 3 types of muscle, give its location, function and characteristics.