What are the main parts of this tree?

1

1. What are the main parts of this tree?
2. What is the function of each part?

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REVIEW
How do plants obtain energy?
AUTOTROPHS
In the food chain, they are the producer.
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PLANT STRUCTURE AND FUNCTION
Anchors the plant Collects water and nutrients
for plant
Roots
LEAVES
Stem
Above ground Transports nutrients
STEM
Leaves
Photosynthesis Transpiration
ROOTS
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ROOTS
Roots can be short or long
Roots can be thick and massive or thin and
thread-like.
Most roots grow in the soil, some do not.
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TYPES OF ROOTS
1.
TAPROOTS like carrots and beets sing
thick structures with smaller branching
roots accumulate and store food
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TYPES OF ROOTS
2.
Fibrous Roots have many small branching
roots from a central point
example grass
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TYPES OF ROOTS
3.
PROP ROOTS originate above ground to
help support the plant
example corn
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STEMS
Stems transport water, dissolved minerals, and
sugar to and from roots and leaves.
1.
2.
Herbaceous Stems
Woody stems
Fleshy, green stems,
Can also carry out photosynthesis.
Grow year after year Have cork
tissue for protection
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LEAVES

• The primary function of the leaves is
  photosynthesis.

• Sunlight passes through the transparent cuticle
  into the photosynthetic tissues just beneath the
  leaf surface.

Cuticle
Upper epidermis
Palisade Layer (where most chloroplasts are
found)
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LEAVES
Size, Shape, and type of leaves vary enormously.
Leaf Arrangement
Opposite Arrangement
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Section 23.2 Summary pages 612-621
LEAVES

• Gases can also move in and out of a leaf through
  the stomata, which are located in the upper
  and/or lower epidermis.

Stomata
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Section 23.2 Summary pages 612-621
LEAVES

• Guard cells are tiny cells that surround and
  control the size of a stoma.

• The loss of water through the stomata is called
  transpiration.

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Section 23.2 Summary pages 612-621
LEAVES
Stoma
Transpiration
Water

• When water enters the guard cells, the pressure
  causes them to bow out, opening the stoma.

Guard cell
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Section 23.2 Summary pages 612-621
LEAVES
Transpiration
Water

• As water leaves the guard cells, the pressure is
  released and the cells come together, closing the
  stoma.

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Section 23.2 Summary pages 612-621
LEAVES
One way to distinguish among different groups of
plants is to examine the pattern of veins in
their leaves.
PARALLEL VEINS (Monocot)
NET-LIKE VEINS (Dicot)
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Section 23.3 Summary pages 622-625
PLANT RESPONSES

• Although a plant lacks a nervous system and
  usually cannot make quick responses to stimuli,
  it does have mechanisms that enable it to respond
  to its environment.

• Plants can respond to
• Gravity
• Light
• Temperature

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Section 23.3 Summary pages 622-625
PLANT RESPONSES

• Tropism is a plants response to an external
  stimulus.

• The tropism is called positive if the plant grows
  toward the stimulus.

• The tropism is called negative if the plant grows
  away from the stimulus.

WE WILL LOOK AT THREE TYPES OF TROPISM
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Section 23.3 Summary pages 622-625
TROPISM
The growth of a plant toward light is called
phototropism.

• As these cells lengthen, the stem bends toward
  the light.

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Section 23.3 Summary pages 622-625
TROPISM
Gravitropism is plant growth in response to
gravity.
Stems usually exhibit a negative gravitropism.
Roots that grow down into the soil are able to
anchor the plant and can take in water and
dissolved minerals.
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Section 23.3 Summary pages 622-625
TROPISM
Some plants exhibit another tropism called
thigmotropism, which is a growth response to
touch.

• Because tropisms involve growth, they are not
  reversible.

• The position of a stem that has grown several
  inches in a particular direction cannot be
  changed.

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Section 23.3 Summary pages 622-625
PLANT RESPONSES

• A responsive movement of a plant that is not
  dependent on the direction of the stimulus is
  called a nastic movement.

• An example of a nastic response is the sudden
  closing of the hinged leaf of a Venuss-flytrap.

• Nastic movements do not involve growth.

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Section 1 Check
Question 1
Most plants produce their own food in the
form of _______.
A. cellulose
B. proteins
C. glucose
D. chlorophyll
The answer is C.
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Section 1 Check
Question 2
Which of the following is NOT a function of
most plant roots?
A. absorbing water and nutrients
B. conducting photosynthesis
C. store starch
D. anchoring the plant
The answer is B.
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Section 2 Check
Question 3
Most roots that humans eat are _____ roots.
A. taproots
B. fibrous roots
C. prop roots
D. aerial roots
The answer is A, taproots.
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Chapter Assessment
Question 4
If a plant becomes too dry, are the stomata in
the leaves more likely to be open or closed?
Answer
The stomata are more likely to be closed to
prevent any more water loss from the plant.
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Chapter Assessment
Question 5
What is the main difference between tropisms and
nastic responses?
Answer
The main difference between the two is that
tropisms are not reversible and nastic responses
are reversible. Also, nastic responses do not
depend on the direction of the stimulus, tropisms
do.
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Question 6
As you walk through a room, you notice that a
plant sitting on a table 2 m from a window is
leaning toward the window. What type of response
is the plant exhibiting?
Answer
phototropism.