Name ______________________________ Class ___________________ Date __________________
CHAPTER 29 ACTIVE READING WORKSHEETS
PLANT STRUCTURE AND
FUNCTION
Section 29-4: Leaves
Read the passage below, which covers topics from your textbook. Answer the
questions that follow.
Leaves come in a wide variety of shapes and sizes and are an important
feature used for plant identification. Leaves can be round, straplike,
needlelike, or heart-shaped. The broad, flat portion of a leaf, called the blade,
is the site of most photosynthesis. The blade is usually attached to the stem
by a stalklike petiole. The maple leaf is a simple leaf; it has a single blade.
In compound leaves such as the white clover, the blade is divided into
leaflets. In some species, the leaflets themselves are divided. The result is a
doubly compound leaf, such as that of the honeylocust.
Leaves consist of three tissue systems. The dermal tissue system is
represented by the epidermis. In most leaves the epidermis is a single layer of
cells coated with a nearly impermeable cuticle. Water, oxygen, and carbon
dioxide enter and exit the leaf through stomata in the epidermis. Epidermal
hairs are often present and usually function to protect the leaf from insects
and intense light.
In most plants, photosynthesis occurs in the leaf mesophyll, a ground
tissue composed of chloroplast-rich parenchyma cells. In most plants, the
mesophyll is organized into layers. The palisade mesophyll layer occurs
directly beneath the upper epidermis and is the site of most photosynthesis.
Palisade cells are columnar and appear to be packed tightly together in one or
two layers. However, there are air spaces between the long side walls of
palisade cells. Beneath the palisade layer is the spongy mesophyll. It
consists of irregularly shaped cells surrounded by large air spaces, which
allow oxygen, carbon dioxide, and water to diffuse into and out of the leaf.
Read the question and write your answer in the space provided.
SKILL: Vocabulary Development
1. What is the meaning of the term impermeable in the passage?
_______________________________________________________________
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Modern Biology
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Leaves
Name ______________________________ Class ___________________ Date __________________
Read each description related to leaves. On the line, write the term described.
_____________________ 2. the leaf’s dermal tissue system
_____________________ 3. structure that attaches the blade to the stem
_____________________ 4. structure that consists of irregularly shaped cells
surrounded by large air spaces
_____________________ 5. the broad, flat leaf part where most photosynthesis
occurs
_____________________ 6. ground tissue made up of chloroplast-rich
parenchyma cells
_____________________ 7. leaf with a single blade
_____________________ 8. the plant part whose columnar cells have air spaces
between them
_____________________ 9. leaf with a divided blade
Write your answers in the spaces provided.
SKILL: Interpreting Graphics
10. The figure below shows the internal structure of a leaf. Write the following
labels on the figure: “Spongy mesophyll,” “Cuticle,” “Palisade mesophyll,”
and “Upper epidermis.” Write your answers
Circle the letter of the word or phrase that best completes the analogy.
11. Simple is to maple leaf as compound is to
a. corn leaf.
b. white clover.
c. vein.
d. Both (a) and (b)
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Modern Biology
120
Leaves