roots, stems, and leaves the three main plant organs are roots, stems, and leaves. these organs are...

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Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: dermal tissue vascular tissue ground tissue.

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Page 1: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

Roots, Stems, and Leaves

• The three main plant organs are roots, stems, and leaves.

• These organs are made up of three main kinds of tissues:– dermal tissue– vascular tissue– ground tissue.

Page 2: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

Plant Tissues

• Dermal tissue –– the “skin” of a

plant. – protects the plant

and prevents water loss.

Page 3: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

Plant Tissues cont.• Vascular tissue

– moves water and nutrients throughout the plant. • Xylem tissue

– moves water. – made up of

tracheids and vessel elements.

• Phloem tissue– moves sugars. – consists of sieve

tube elements and companion cells.

Page 4: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

Plant Tissues cont.

• Ground tissue- – all the cells that lie between dermal and vascular tissues.– made up mostly of parenchyma cells.

• Parenchyma cells have thin cell walls and function in photosynthesis and storage.

– Collenchyma and sclerenchyma• These cells have thick cell walls that help support the plant.

Page 5: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

Plant Tissues cont.

• Meristematic tissue- – responsible for plant

growth. – Produces new cells by

mitosis. – Develop specialized

structures and functions when mature in a process called differentiation

– found at the tips of stems and roots.

Page 6: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

Roots• 2 types of roots-

– Taproot : One big primary root + small secondary roots– Fibrous root: Primary and secondary roots = same size

• Functions: – anchor a plant in the ground. – absorb water and dissolve nutrients from the soil.

• Root pressure forces water upward through the xylem toward the stem.

Page 7: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

Stems

• Functions:– They produce leaves, branches, and flowers. – They hold leaves up to the sunlight. – They also carry water and nutrients between roots and leaves.

• Arrangement of tissues – Monocots: vascular bundles are scattered – Dicots : vascular bundles are arranged in a ring.

• These vascular bundles contain xylem and phloem tissue.

• Growth:– Primary : grows longer– Secondary: grows wider

Page 8: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

Leaves• main organs of

photosynthesis. – make food (sugars) – made up of a

specialized ground tissue called mesophyll cells.

• Mesophyll : many chloroplasts responsible for photosynthesis

• veins : Xylem and phloem tissues

• Stomata: small openings – prevent water loss.

Page 9: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

Transport in Plants• Capillary action:

– Cohesion- forces between water and water molecules

– Adhesion – forces between water and other molecules

• Transpiration pull – water moves from areas

where there is plenty of water to areas where there is little water.

• Pressure-flow hypothesis– explains how phloem

transport happens• sugars move from areas

of high concentration to areas of low concentration.

Page 10: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

D

C

BA

Which part is responsible for photosynthesis?

Page 11: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

If a plant becomes too dry, are the stomata in the leaves more likely to be open or closed?

Page 12: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

• Which tissue is found in the center of a plant stem?– A. dermal tissue– B. vascular tissue – C. ground tissue

Page 13: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

• Which of the three kinds of ground tissue serve mainly for storage? – A.parenchyma – B. collenchyma – C. sclerenchyma

Page 14: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

• Cells that can differentiate into many plant tissues are found in A. the vascular cylinder.

B. dermal tissue.

C.meristematic tissue.

Page 15: Roots, Stems, and Leaves The three main plant organs are roots, stems, and leaves. These organs are made up of three main kinds of tissues: –dermal tissue

• Photosynthetic tissues in a leaf include the– A.phloem.– B.vein.– C.palisade mesophyll.

• A process in which water is lost through the leaves of a plant is called– A.transpiration.– B.photosynthesis.– C.glycolysis.