key concept plants have specialized cells and tissue systems
DESCRIPTION
KEY CONCEPT Plants have specialized cells and tissue systems. Parenchyma cells are the most common plant cell type. store starch, oils and water help heal wounds to the plant have thin flexible walls. Plant tissues are made of three basic cell types. they are strong and flexible. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/1.jpg)
21.1 Plant Cells and Tissues
KEY CONCEPT Plants have specialized cells and tissue systems.
![Page 2: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/2.jpg)
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
![Page 3: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/3.jpg)
21.1 Plant Cells and Tissues
– they are strong and flexible.– celery strings are strands of collenchyma.– they have unevenly thick cell walls.
• Collenchyma cells provide support to a growing plant.
![Page 4: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/4.jpg)
21.1 Plant Cells and Tissues
– second cell wall hardened by lignin– die when they reach maturity – used by humans to make linen and rope
• Sclerenchyma cells are the strongest plant cell type.
![Page 5: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/5.jpg)
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
![Page 6: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/6.jpg)
21.1 Plant Cells and Tissues
– provides support – stores materials in roots and stems – most commonly made of parenchyma
• Ground tissue is found inside a plant.
![Page 7: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/7.jpg)
21.1 Plant Cells and Tissues
stem
leaf
root
– two networks of hollow tubes
– xylem transports water and minerals
– phloem transports photosynthetic products
• Vascular tissue transports water, minerals and organic compounds.
![Page 8: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/8.jpg)
21.1 Plant Cells and Tissues KEY CONCEPT 20-2 The vascular system allows for the transport of water, minerals, and sugars.
![Page 9: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/9.jpg)
21.1 Plant Cells and Tissues Water and dissolved minerals move through xylem.
• Xylem contains specialized cells. – vessel elements are short and wide– tracheid cells are long and narrow – xylem cells die at maturity
vesselelement
tracheid
![Page 10: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/10.jpg)
21.1 Plant Cells and Tissues
– Plants passively transport water through the xylem.– Cohesion is the tendency of water molecules to bond
with each other.
• The cohesion-tension theory explains water movement.
– Adhesion is the tendency of water molecules to bond with other substances.
![Page 11: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/11.jpg)
21.1 Plant Cells and Tissues
– absorption occurs at roots
• Water travels from roots to the top of trees.
– cohesion and adhesion in xylem– transpiration at leaves
![Page 12: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/12.jpg)
21.1 Plant Cells and Tissues
– water vapor exits leaf stomata– helps pull water to the top
branches
• Transpiration is the loss of water vapor through leaves.
![Page 13: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/13.jpg)
21.1 Plant Cells and Tissues Phloem carries sugars from photosynthesis throughout the plant.
• Phloem contains specialized cells. – sieve tube elements have
holes at ends– companion cells help sieve
tube elements – unlike xylem, phloem tissue is
alive
![Page 14: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/14.jpg)
21.1 Plant Cells and Tissues
– plants actively transport sugar from the source– sugar flows to the sink due to pressure differences
sugars
phloem xylem
water
Sugars move from their source, such as photosynthesizing leaves, into the phloem.
1
The sugars move into the sink, such as root or fruit, where the are stored.
3
Water moves from the xylem into the phloem by osmosis, due to the higher concentration of the sugars in the phloem. The water flow helps move sugars through the phloem.
2
• The Pressure-flow model explains sugar movement.
![Page 15: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/15.jpg)
21.1 Plant Cells and Tissues KEY CONCEPT 21.3 Roots and stems form the support system of vascular plants.
![Page 16: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/16.jpg)
21.1 Plant Cells and Tissues Roots anchor plants and absorb mineral nutrients from soil.
• Roots provide many functions.– support the plant– absorb, transport,
and store nutrients – root hairs help
absorption
![Page 17: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/17.jpg)
21.1 Plant Cells and Tissues
root cap
– root cap covers the tip
• There are several parts of a root.
![Page 18: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/18.jpg)
21.1 Plant Cells and Tissues
apical meristem
– root cap covers the tip
• There are several parts of a root.
– apical meristem is an area of growth
• There are several parts of a root.
![Page 19: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/19.jpg)
21.1 Plant Cells and Tissues
– vascular cylinder contains xylem and phloem
vascular cylinder
– root cap covers the tip
• There are several parts of a root.
– apical meristem is an area of growth
• There are several parts of a root.
![Page 20: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/20.jpg)
21.1 Plant Cells and Tissues
– Fibrous root systems have fine branches.
Fibrous root Taproot
• There are two main types of roots.
– Taproot systems have one main root.
![Page 21: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/21.jpg)
21.1 Plant Cells and Tissues Stems support plants, transport materials, and provide storage.
• Stems have many functions. – support leaves and flowers – house most of the vascular system – store water
Baobab trees Cactus
![Page 22: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/22.jpg)
21.1 Plant Cells and Tissues
– grow underground for storage
Ginger rhizomes Potato tubers
Stems support plants, transport materials, and provide storage.
• Stems have many functions. – support leaves and flowers – house most of the vascular system – store water
![Page 23: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/23.jpg)
21.1 Plant Cells and Tissues
– grow underground for storage
Stems support plants, transport materials, and provide storage.
• Stems have many functions. – support leaves and flowers – house most of the vascular system – store water
– form new plants
Strawberry stolons
![Page 24: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/24.jpg)
21.1 Plant Cells and Tissues • Some stems are herbaceous and conduct photosynthesis.
![Page 25: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/25.jpg)
21.1 Plant Cells and Tissues • Some stems can be woody, and form protective bark.
![Page 26: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/26.jpg)
21.1 Plant Cells and Tissues
• Secondary growth increases a plant’s width.
• Primary growth increases a plant’s length.
![Page 27: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/27.jpg)
21.1 Plant Cells and Tissues
• Tree rings help determine the age of a tree.
heartwood
bands bark
one year of growth
sapwood
![Page 28: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/28.jpg)
21.1 Plant Cells and Tissues
KEY CONCEPT Leaves absorb light and carry out photosynthesis.
![Page 29: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/29.jpg)
21.1 Plant Cells and Tissues
Most leaves share some similar structures.
• The blade is usually broad and flat. – collects sunlight for
photosynthesis– connects to the stem by a
petiole
blade
petiole
![Page 30: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/30.jpg)
21.1 Plant Cells and Tissues
• Mesophyll is between the leaf’s dermal tissue layers.
cuticle
upperepidermis
palisademesophyll
spongymesophyll
lowerepidermis
![Page 31: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/31.jpg)
21.1 Plant Cells and Tissues
– Stomata open and close when guard cells change shape.
– When stomata are open, water evaporates and gas exchanges.
– Stomata close at night and when plant loses too much water.
guard cells stoma
• Guard cells surround each stoma.
![Page 32: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/32.jpg)
21.1 Plant Cells and Tissues
• Leaves may be simple, compound, or double compound.
Simple leaf Compound leaf Double compound leaf
![Page 33: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/33.jpg)
21.1 Plant Cells and Tissues
• Leaf veins may be parallel or pinnate.
Pinnate veinsParallel veins
![Page 34: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/34.jpg)
21.1 Plant Cells and Tissues
• Leaf margins may be toothed, entire, or lobed.
Toothed margin Entire margin Lobed margin
![Page 35: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/35.jpg)
21.1 Plant Cells and Tissues
Most leaves are specialized systems for photosynthesis.
• There are two types of mesophyll cells. – both types contain chloroplasts – palisade mesophyll absorbs sunlight – spongy mesophyll connects to stomata
xylem
phloem
cuticle
upperepidermis
palisademesophyll
spongymesophyll
stomata
lowerepidermis
![Page 36: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/36.jpg)
21.1 Plant Cells and Tissues
– for extreme temperatures, ex: pine needles
• Leaves have many adaptations.
![Page 37: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/37.jpg)
21.1 Plant Cells and Tissues
• Leaves have many adaptations.
– for extreme temperatures, ex: pine needles
– for water loss,ex: cactus spines
![Page 38: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/38.jpg)
21.1 Plant Cells and Tissues
– for aquatic environments, ex: water lily
• Leaves have many adaptations.
– for extreme temperatures, ex: pine needles
– for water loss,ex: cactus spines
![Page 39: KEY CONCEPT Plants have specialized cells and tissue systems](https://reader036.vdocuments.us/reader036/viewer/2022062722/568138e0550346895da09235/html5/thumbnails/39.jpg)
21.1 Plant Cells and Tissues
– for aquatic environments, ex: water lily
– for getting food,ex: Venus’ flytrap
• Leaves have many adaptations.
– for extreme temperatures, ex: pine needles
– for water loss,ex: cactus spines