Plant+structure+&+function

http://www.phschool.com/science/biology_place/biocoach/plants/structure.html

Concept 1: Basic Plant Structure Plants have three vegetative organs: roots, stems, and leaves. Use information from the illustration to answer the questions below. 1. Which part of the leaf has the main function to carry out photosynthesis?

2. The petiole is part of which plant organ?

3. Where on the stem are the axillary buds attached?

4. From what plant part does the shoot develop?

Concept 3: Plant Tissue Systems The tissues of a plant are organized into three tissue systems: the dermal tissue system, the ground tissue system, and the vascular tissue system. Use information from the table to answer the questions below it. Tissue System and Its Functions	Component Tissues	Location of Tissue Systems Dermal Tissue System • protection • prevention of water loss	Epidermis Periderm (in older stems and roots) Ground Tissue System • photosynthesis • food storage • regeneration • support • protection	Parenchyma tissue Collenchyma tissue Sclerenchyma tissue Vascular Tissue System • transport of water and minerals • transport of food	Xylem tissue Phloem tissue 1. Where is the vascular tissue system located in roots?

2. Where is the ground tissue system located in a (dicot) stem?

3. What type of tissue are the veins in leaves?

4. Name three tissues in the ground tissue system.

Concept 5: Ground Tissues The three types of ground tissue, parenchyma, collenchyma, and sclerenchyma, function in photosynthesis, storage, regeneration, support, and protection. Use information from the table to help answer the questions below it. Ground Tissue	Parenchyma Tissue	Collenchyma Tissue	Sclerenchyma Tissue * Function	• Photosynthesis • Food storage • Healing and tissue regeneration	• Support in young stems, roots, and petioles	• Rigid support • Protection Cell Types in This Tissue	Parenchyma cells

Collenchyma cells

Sclereid cells & fiber cells 1. Potatoes contain food in the form of starch, which ground tissue are you eating when you eat mashed potatoes?
 * Some texts include tracheids and vessels as components of sclerenchyma tissue.

2. The part of rhubarb that people eat is the petiole of a large leaf. Which tissue provides support for rhubarb?

3. Which ground tissue is a major component of the blades of spinach leaves?

4. Which ground tissue makes the shell of a nut hard?

Concept 4: Dermal Tissues The dermal tissue system protects the soft tissues of plants and controls interactions with the plants' surroundings. The epidermis is a dermal tissue that is usually a single layer of cells covering the younger parts of a plant. It secretes a waxy layer called the cuticle that inhibits water loss.

Some of the many types of cells in the epidermis are shown below.

Most epidermal cells lack chloroplasts.

Guard cells contain chloroplasts and regulate gas exchange between the inside of the leaf and the surrounding air.

Epidermal hairs lower water loss by decreasing the flow of air over the plant surface, which in turn, slows the loss of water from the plant.

Glandular hairs prevent herbivory by storing substances that are harmful to insects.

Root hairs increase water uptake by increasing the surface area of the cell. In older stems and roots, the epidermis may be replaced by the periderm, which provides protection while permitting gas exchange.

The outer layer of periderm, cork tissue, is composed of dead cells whose cell walls are impregnated with a waxy material, suberin. Concept 6: Vascular Tissues Vascular tissue is composed of xylem and phloem, which function in the transport of water and dissolved substances. Use the information in the table to help answer the questions below it. Vascular Tissue	Xylem Tissue	Phloem Tissue Function	• Conduct water and dissolved minerals • Support	• Conduct food and other organic substances Cell Types Unique to This Tissue	Tracheids Vessel members Companion cells	Sieve-tube elements Additional Cell Types in This Tissue	Parenchyma cells Fibers Parenchyma cells Fibers

1. Which tissue is most likely to transport dissolved sugar?

2. What tissue transports water through dead cells?

3. Companion cells are unique to which tissue?

4. Vessel members are unique to which tissue?

Concept 7: Primary Growth Primary growth is the lengthening of the stem and roots. All plant growth occurs by cell division and cell elongation. Cell division occurs primarily in regions of undifferentiated cells known as meristems.

Cell division in the apical meristems and subsequent elongation and maturation of the new cells produces primary growth.

The other type of growth, secondary growth, is the increase in girth of stems and roots. Primary Growth and the Location of Apical Meristems	Cell Elongation Animate Animate Notice that the internode distance increases during primary growth (elongation), but then this distance becomes set. 1. Meristems make it possible for plants to have indeterminate growth. Explain the term"indeterminate growth."

2. The term "apical" comes from the word "apex." Explain why the term "apical meristem" is used for the meristems in root tips and axillary buds as well as in apical buds.

Concept 8: Primary Growth of Stems The apical meristem produces the three primary meristems, protoderm, procambium, and ground meristem, which develop into dermal tissues, vascular tissues, and ground tissues respectively. Use the information in the illustration to help answer the questions below it.

1. Xylem and phloem tissues are derived from which primary meristem?

2. What is the dermal tissue called that is found in young stems and roots?

3. From which primary meristem is the epidermis derived?

Concept 10: Primary Growth of Roots In roots, the three primary meristems, protoderm, procambium, and ground meristem, develop from the apical meristem and differentiate into epidermis, vascular tissues, and ground tissues. Label the longitudinal section of a root below. On the left, label the regions in which cell division, cell elongation, and cell differentiation take place. On the right, label the apical meristem, the three primary meristems, and the three primary tissues. Click on the Check Your Answers button to compare your answer with the correct answers.

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Concept 11: Structure of Young Roots In young dicot roots, the epidermis, cortex, endodermis, and vascular cylinder (stele) are arranged in a characteristic pattern that is different from the pattern in stems. The photomicrograph below shows part of the cross section of a young dicot root. To see a color-coded display of a root, click on the Study button. To practice identifying areas of the root, click on the Practice button.

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practice Cross Section of a Young Dicot Root

Concept 12: Monocot Stems and Roots The arrangement of tissues in monocot stems and roots is somewhat different from the arrangement of tissues in dicots. Label the tissues that are indicated by numbers, and answer the questions by typing in the input boxes. Most monocots undergo only primary growth. Cross Section of a Monocot Stem

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6. How is the arrangement of vascular tissue different in monocot and dicot stems?

Cross Section of a Monocot Root

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14. How is the arrangement of vascular tissues in a monocot root different from a dicot root?

Concept 13: Leaf Structure The structure of leaves promotes photosynthesis and allows the control of gas exchange and water loss. 1. What structure secretes a waxy cuticle that prevents water loss?

2. How does the lower epidermis differ from the upper epidermis?

3. How do guard cells differ from other epidermal cells, and what is their function?

Concept 14: Lateral Meristems In woody plants, secondary growth of stems and roots occurs through the activity of two lateral meristems: the vascular cambium and the cork cambium. Use information in the graphic to answer the questions below it. Secondary growth occurs in all gymnosperms and most angiosperms, including most dicots but few monocots.

1. From which cambium does the outer bark of a woody stem develop?

2. From which cambium does secondary xylem and secondary phloem develop?

3. Which cambium develops from parenchyma cells located between vascular bundles?

4. From which cells does fascicular cambium develop?

5. Which secondary meristem forms from the fascicular and interfascicular cambium?

Concept 15: Secondary Growth Each time a cambium cell divides, one daughter cell, the initial, remains part of the cambium and the other daughter cell, the derivative, undergoes differentiation. Use information from the animation to help answer the questions below it. Animate Secondary xylem develops into the wood of a tree trunk. The secondary phloem is a thin layer to the outside of the vascular cambium.

1. What two types of tissue are produced by the vascular cambium?

2. What type of tissue does a derivative cell become part of if that cell is to the outside of the vascular cambium?

3. What type of tissue does a derivative cell become part of if that cell is to the inside of the vascular cambium?