7: Plant Tissues

Question 1

What are the types of tissues, components, and their functions?

Answer 1

Dermal - Epidermis & Periderm (Protection and prevent loss of water)

Ground - Parenchyma, Sclerenchyma and Collenchyma (Metabolism, storage and support)

Vascular - Xylem & Phloem (Transport water and sugar)

Question 2

What are meristematic tissues?

Answer 2

Undifferentiated tissues which consists of clumps of small cells with dense cytoplasm and proportionately large nuclei

Apical meristem - elongation of root and shoots

Lateral meristem - increase in girth of trunk

Question 3

What are the three primary meristems of apical meristem?

Answer 3

Protoderm - forms epidermis

Procambium - forms primary vascular tissue

Ground meristem - differentiates into ground tissue

Question 4

What are the types of lateral meristems? Explain.

Answer 4

Vascular cambium - produces secondary vascular tissues: secondary xylem and phloem

Cork cambium - produces cork cells and replaces the epidermis with thicker, rougher periderm

Question 5

What is the organisation of the plant body?

Answer 5

A vascular plant consists of:

• root system which anchors plant and penetrates soil to absorb water and ions
• shoot systems which consists of stem as framework to position leaves and leaves as principle sites of photosynthesis

Question 6

What is primary and secondary growth?

Answer 6

Primary growth: results from cell division at the apical meristems at the plant tip resulting in the growth of length

Secondary growth: results from cell division at the lateral meristem which increases the shoot’s girth and thickens the plant body

Question 7

What are dermal tissues?

Answer 7

Guard cells - dumbbell-shaped cells flanking the stomata

Trichomes - hairlike outgrowth that regulates microclimate

Root hairs - tubular extensions of epidermal cells to increase root surface area

Question 8

What are the functions of ground tissue?

Answer 8

Parenchyma: stores food and water

Collenchyma: provides support for plant organs

Sclerenchyma: for support with secondary walls impregnated with lignin

Question 9

Explain xylem

Answer 9

• dead and lignified at functional maturity
• is the principle water-conducting tissue
• primary xylem derived from procambium
• secondary xylem formed by vascular cambium

Question 10

Explain phloem

Answer 10

• alive at functional maturity
• principle food-conducting tissue in vascular plants, located toward the outer part of roots and stems