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Plant Cells, Tissues, and Organs

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Presentation on theme: "Plant Cells, Tissues, and Organs"— Presentation transcript:

1 Plant Cells, Tissues, and Organs
Section 2.1 Homework Pg. 62 #1-4

2 Chapter 2 Plants: From Cells to Systems
In this chapter you will investigate: how plant cells specialize to form different tissues the link between cells, tissues, organs, and systems in plants the function of plant tissues and organs how organs work together to meet the needs of a plant diseases that threaten plant tissues and organs

3 Organization in a multi-cellular organism
Hierarchical levels of organization: Organism Organ systems Organs Tissues Cells Most complex Least complex

4 Specialized plant cells

5 simplest level of organization
Heart muscle cell Circulatory system Heart muscle tissue Heart Zebra Maple tree Epidermal cell Dermal tissue Leaf Shoot system simplest level of organization a collection of similar cells that perform a particular function a structure composed of two or more tissues working together to perform a complex body function consists of one or more organs and other structures that work together to perform a vital body function made up of many different organ systems working together

6 Plant stem cells are called meristematic cells.
Meristematic cells have the potential to constantly divide and differentiate. photosynthesis gas exchange material transport support

7 Meristematic cells allow plants to constantly replace old organs.
All growth in the plant is due to the division of meristem. Most occurs at the terminal bud. Buds Regions containing meristematic cells

8 Apical meristems Lateral meristems
Found in buds at tips of roots and shoots. Responsible for increase in height. Lateral meristems Responsible for increase in width.

9 Growth is controlled by chemicals called auxins.
Produced by actively dividing cells. Signal neighbouring cells not to divide.

10 moves substances through plant
Plant tissue types Meristematic tissue Differentiates into... Dermal tissue covers outer surface Vascular tissue moves substances through plant Ground tissue supportive tissue

11 Every plant organ contains tissue from all three systems.

12 Dermal tissue Plant’s outermost layer Two types: Epidermal tissue
thin layer of cells; covers non-woody surfaces of plant Periderm tissue covering that forms the woody surface on stems/large roots

13 Adaptations of dermal tissue
Function Root hairs Maximize water uptake Leaf hairs Contain chemical irritants Waxy cuticle Makes surface waterproof

14 Vascular tissue system of tubes
distributes absorbed water, minerals and nutrients

15 Xylem Phloem Dead, hollow tissue
Transports water and minerals upwards from roots Phloem Living tissue Transports sugars produced by leaves, to the rest of the plant

16 Non-woody plant Woody plant
Vascular tissue arranged in bundles Woody plant Vascular tissue forms a ring along trunk diameter

17 Ground tissue “Filler” tissue between dermal and vascular
Variety of functions: photosynthesis, in the green parts of plants storage of carbohydrates in the roots storage and support in the stems

18 Plants have two organ systems
SHOOT SYSTEM Stem, leaves, flowers, fruit (if present) ROOT SYSTEM One or more separate roots

19 The Root System Functions: Structure: anchor the plant
absorb water and minerals from soil store food Structure: no leaves usually grows below ground composed of dermal tissue root hairs maximize surface area

20 Spaces between cortex cells allow water to move from soil to the endodermis.
Endodermis controls transport of water and minerals between cortex and xylem.

21 Types of roots: Taproots vs. Fibrous roots

22 The Shoot System Structure: Functions:
carry out photosynthesis (leaves) structural support transport substances throughout plant produce flowers for sexual reproduction Structure: usually above ground components: leaves stem flowers/fruit

23 Leaves Main site of photosynthesis:
chloroplasts contain chlorophyll; absorb sunlight’s energy glucose is used for cellular respiration, plant growth, and energy storage CO2+ H2O + light energy ___________+ O2

24 Layers of the Leaf

25 Transparent outer layer, made of dermal tissue.
Epidermis Transparent outer layer, made of dermal tissue. The upper epidermis secretes waxy cuticle.

26 The lower epidermis contains stomata (holes) for exchange of gases ((H2O, O2, CO2).
opening/closing of stomata is controlled by guard cells

27 Middle layers, sandwiched between upper and lower epidermis
Mesophyll Middle layers, sandwiched between upper and lower epidermis Palisade cells – Perform most of the photosynthesis in the leaf contain many chloroplasts tightly-packed together

28 Spongy parenchyma cells – Loosely-packed
to allow the movement of gases within the leaf


30 Vascular bundles Composed of vascular tissue (xylem and phloem) arranged in bundles visible on the leaf as veins

31 Chloroplasts membrane- bound organelle
contains more membrane- bound sacs (thylakoids) thylakoids are arranged in stacks (grana)

32 CO2+ H2O + light energy  glucose + O2
Leaves have structures that help the plant obtain and keep the reactants for photosynthesis: CO2+ H2O + light energy  glucose + O2 Spongy parenchyma is loosely-packed to allow gases to circulate to all photosynthesizing cells. Cuticle is transparent to let light through. Palisade cells are tightly-packed to maximize the area exposed to the Sun. Guard cells close the stomata on hot days to prevent evaporation of water.

33 The Stem Functions: Support for shoot system Transport of nutrients and water to leaves Specialized stems: Food storage, protection, photosynthesis, reproduction Uses: sugar cane, medicines, cork, wood and paper

34 Flowers Contain reproductive structures (male/female/both) Male Female
Organ Stamen Carpel/Pistil Gamete Pollen grains Eggs

35 Fertilization occurs by pollination, and produces seeds.
contained in the fruit Pollination can be assisted by wind, animals, or insects.

36 Flowers: Adaptations To attract pollinators, plants will have attractive flowers or nectar.

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