21 1 Plant Cells and Tissues KEY CONCEPT

21. 1 Plant Cells and Tissues KEY CONCEPT Plants have specialized cells and tissue systems.

21. 1 Plant Cells and Tissues Plant tissues are made of three basic cell types. • Parenchyma cells are the most common plant cell type. – store starch, oils and water – help heal wounds to the plant – have thin flexible walls

21. 1 Plant Cells and Tissues • Collenchyma cells provide support to a growing plant. – they are strong and flexible. – celery strings are strands of collenchyma. – they have unevenly thick cell walls.

21. 1 Plant Cells and Tissues • Sclerenchyma cells are the strongest plant cell type. – second cell wall hardened by lignin – die when they reach maturity – used by humans to make linen and rope – makes up the hard or gritty part of a fruit or vegetable

21. 1 Plant Cells and Tissues Plant organs are made of three tissue systems. • Dermal tissue covers the outside of a plant. – protects the plant – secretes cuticle of leaves – forms outer bark of trees

21. 1 Plant Cells and Tissues • Ground tissue is found inside a plant. – provides support – stores materials in roots and stems – most commonly made of parenchyma

21. 1 Plant Cells and Tissues • Vascular tissue transports water, minerals and organic compounds. – two networks of hollow tubes stem – xylem transports water and minerals – phloem transports photosynthetic products leaf root

21. 1 Plant Cells and Tissues Which type of cell is found in the hard or gritty parts of fruits and vegetables? A. B. C. D. Collenchyma Sclerenchyma Parenchyma Plasmodesmata

21. 1 Plant Cells and Tissues Plant cells that have thin walls and store starch, oils, and water are A. B. C. D. Parenchyma Collenchyma Sclerenchyma Vascular cells

21. 1 Plant Cells and Tissues Dead parenchyma cells that make up bark form a type of A. B. C. D. Collenchyma tissue Vascular tissue Dermal tissue Ground tissue

21. 1 Plant Cells and Tissues A plant’s ground tissue is found A. B. C. D. In its outer layer Only in its leaves Above the ground Throughout the plant

21. 1 Plant Cells and Tissues Water and dissolved minerals are carried from the roots to the rest of the plant by the A. B. C. D. Dermal tissue Ground tissue Xylem Phloem