Unit 6 - Lesson 1 - Lecture

​Unit 6

Lesson 1

Plant Seeds and Tissues

Plant Cells and Tissues
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Plant Cells

•Plant cells are identifiable
by their cell walls and
large central vacuole.

•Plants have many types
of cells adapted for
specific purposes.

Multiple Choice

Plant Cells are identifiable by their...

(Choose all that apply)

• cell walls

• large central vacuole

• multiple nuclei

• green cytoplasm

Plant Cells and Tissues
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Plant Cells

Parenchyma Cells

•Most flexible, thin-walled cells found throughout the plant are parenchyma cells.

•Can undergo cell division when mature, allowing them to repair damaged parts
of plants.

•Basis of many plant structures and functions, including:

•Storage

•Photosynthesis

•Gas exchange

•Protection

Multiple Choice

cells in which photosynthesis and food storage occur

• collenchyma

• sclerenchyma

• parenchyma

Plant Cells and Tissues
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Plant Cells

Collenchyma Cells

•Plant cells that often are elongated and occur in long strands or cylinders that
provide support for the surrounding cells are collenchyma cells.

•Have unevenly thickened cell walls, which allow the cells to stretch and be
flexible.

•Retain the ability to undergo cell division when mature.

Multiple Choice

Which characteristic does collenchyma give to a plant?

• color

• flexibility

• height

• taste

Plant Cells and Tissues
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Plant Cells

Sclerenchyma Cells

•Plant cells that lack cytoplasm and other living components when they mature,
leaving thick, rigid cell walls are called sclerenchyma cells.

•Sclerenchyma cells provide support for the plant and transport of materials.

•Classified as either sclereids or fibers

•Sclereids are also called stone cells, short and irregularly shaped

•Fibers are needle shaped, when stacked together they form a tough elastic
tissue

Multiple Choice

cells that provide strength such as sclereids and fibers

• collenchyma

• sclerenchyma

• parenchyma

Plant Tissues

•Tissues are groups of cells that work together to perform a function.

•A plant tissue can be composed of one or more types of cells.

•There are four different tissue types found in plants – meristematic, dermal,
vascular, and ground.

Plant Cells and Tissues
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Multiple Choice

Which of the following is not one of the four different tissue types found in plants?

• epidermal

• dermal

• meristematic

• vascular

Plant Tissues

Meristematic tissue

•Meristematic tissues make up meristems, or
regions of rapidly dividing cells which produce
new cells for plants.

•Apical meristems: tissues at the tips of roots
and stems, responsible for primary growth

•Intercalary meristems: found at one or more
location along a monocot stem

•Lateral meristems: increase root and stem
diameter through secondary growth

Plant Cells and Tissues
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Multiple Choice

Lateral meristems...

• increase root and stem diameter through secondary growth

• tissues at the tips of roots and stems, responsible for primary growth

• found at one or more location along a monocot stem

Plant Tissues

Meristematic tissue

•The vascular cambium is a thin cylinder of
meristematic tissue.

•Can run the entire length of roots or stems

•Some plants also have a type of lateral meristem
called the cork cambium.

•Produces cells that form a protective outside
layer on stems and roots.

Plant Cells and Tissues
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Multiple Choice

True or False: Meristematic tissue Can run the entire length of roots or stems

• True

• False

Plant Tissues

Dermal tissue—the epidermis

•The layer of cells that makes up the outer covering on a plant is the epidermis.

•Epidermal cells resemble pieces of a jigsaw puzzle with interlocking ridges and
dips.

Plant Cells and Tissues
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Plant Tissues

Dermal tissue – the epidermis

•The epidermis has several adaptations to protect the plant and prevent water
loss.

•Changes in the shape of guard cells result in the opening and closing of a
stomata.

•Some epidermal cells have hairlike projections called trichomes, which prevent
insect and animal predation.

•Root hairs are fragile extensions of root epidermal cells.

Plant Cells and Tissues
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Plant Tissues

Vascular tissue

•Xylem is the water-carrying vascular
tissue, composed of specialized cells
called vessel elements and tracheids.

•Vessel elements are tubular cells
stacked end-to-end.

•Lack end walls, allowing free
movement of water from one vessel
element to another

•Tracheids are tubular cells with pitted
ends and end walls.

•Less efficient at moving water than
vessel elements

Plant Cells and Tissues
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Multiple Select

Xylem is the water-carrying vascular tissue, composed of specialized cells called ______ _______and _________

• sieve tube members

• vessel elements

• companion cells

• tracheids

Plant Tissues

Vascular tissue

•Phloem is the main food-carrying tissue in
vascular plants

•Consists of two types of cells, sieve tube
members and companion cells.

•Sieve tube members contain cytoplasm but
lack nuclei and ribosomes when mature.

•Companion cells occur next to sieve tube
cells and have a nucleus.

•Scientists hypothesize that the companion
cell nucleus functions for both cells.

Plant Cells and Tissues
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Multiple Select

Phloem is composed of which two types of cells?

• sieve tube members

• vessel elements

• companion cells

• tracheids

Plant Tissues

Ground tissue

•Plant tissues that are not meristematic, dermal, or vascular tissues are
ground tissues.

•Consists of parenchyma, collenchyma, and sclerenchyma cells

•Functions include photosynthesis, storage, and support

Plant Cells and Tissues
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