Thu 3/30 Activities Learning Target Describe the forms and functions of plant roots and stems. (21.3) Describe the structures that are common to most leaves. (21.4) Identify the adaptations that allow plants to photosynthesize and survive in various climates and regions. ( 21.4) Class Activities *attached below (scroll down)* Website: my.hrw.com Username: bio678 Password:a4s5s Review 21.2 (group activity) *21.3-21.4 Notes / 21.3-21.4 Study Guide WS* ---check/ water plants Biology Sec. 21.3 & 21.4 Notes Sec. 21.3 KEY CONCEPTS Roots and stems form the support system of vascular plants. 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 There are several parts of a root. Root cap covers the tip Apical meristem is an area of growth Vascular cylinder contains xylem and phloem There are two main types of roots. Fibrous root systems have fine branches. Taproot systems have one main root. Stems support plants, transport materials, and provide storage. Stems have many functions. support leaves and flowers Holt McDougal Biology 1 Plant Structure and Function
house most of the vascular system store water grow underground for storage form new plants Some stems are herbaceous and conduct photosynthesis. Some stems can be woody, and form protective bark. Primary growth increases a plant s length. Secondary growth increases a plant s width. Tree rings help determine the age of a tree. Sec. 21.4 KEY CONCEPTS Leaves absorb light and carry out photosynthesis. Most leaves share some similar structures. The blade is usually broad and flat. collects sunlight for photosynthesis connects to the stem by a petiole Mesophyll is between the leaf s dermal tissue layers. Guard cells surround each stoma. 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. Leaves may be simple, compound, or double compound. Leaf veins may be parallel or pinnate. Leaf margins may be toothed (or serrated), entire (smooth), or lobed. Most leaves are specialized systems for photosynthesis. Holt McDougal Biology 2 Plant Structure and Function
There are two types of mesophyll cells. both types contain chloroplasts palisade mesophyll absorbs sunlight spongy mesophyll connects to stomata Leaves have many adatations for extreme temperatures, ex: pine needles for water loss, ex: cactus spines for aquatic environments, ex: water lily for getting food, ex: venus fly trap Holt McDougal Biology 3 Plant Structure and Function
KEY CONCEPT Roots and stems form the support system of vascular plants. VOCABULARY vascular cylinder meristem primary growth root hair fibrous root secondary growth root cap taproot MAIN IDEA: Roots anchor plants and absorb mineral nutrients from soil. Complete the table by filling in each blank with the name of the root part that corresponds to each description. Parts of a Root Description 1. Center of a root Made of xylem and phloem tissues that are surrounded by dermal cells 2. Tiny projections of dermal cells Increase the surface area available for absorbing water 3. Cone of cells at the tip of the root Protects the growing tip as it pushes through the soil Fill in the blank with the term that best completes the sentence. 4. Groups of cells that are located near a growing tip and give rise to new plant cells form a tissue called. 5. Root systems that are made of fine branches of about the same size are called. 6. Root systems that have one main root and can sometimes store food are called. Holt McDougal Biology 4 Plant Structure and Function
continued 7. Plant use energy to absorb water as well as such as nitrogen, iron, and magnesium. 8. The increased concentration of in root cells causes minerals to move into the root by osmosis. MAIN IDEA: Stems support plants, transport materials, and provide storage. 9. The main functions of most stems include,, and. 10. The two plants shown in Figure 3.4 whose stems can store water are and. 11. The plants shown in Figure 3.4 that have underground stems are and. 12. Stems that have little or no wood and often contain chlorophyll for photosynthesis are called stems. 13. Growth that makes stems grow taller or roots grow longer is called growth. 14. Growth that makes stems and roots of woody plants grow wider is called growth. 15. One year of growth on a includes a larger, lighter band of growth that takes place in spring and a smaller, darker band of growth that takes place later in the growing season. Vocabulary Check Fill in the blank with the term from the box that best matches the description. 16. tough covering on root tip 17. unspecialized tissue of dividing cells 18. houses xylem and phloem 19. increases surface area of a root Holt McDougal Biology 5 Plant Structure and Function
Section 4: Leaves KEY CONCEPT Leaves absorb light and carry out photosynthesis. VOCABULARY blade petiole mesophyll guard cell MAIN IDEA: Most leaves share similar structures. In the box below, sketch a leaf attached to a stem. Label the blade, petiole, and stem. Fill the 1. in blank with the word or phrase that best completes the sentence. 2. The of a leaf collects sunlight for photosynthesis. 3. The connects a leaf to the stem of a plant. 4. The marks where a leaf ends. It grows between the petiole and the stem of a plant.. 5. The outer covering of leaves is made of tissue that is often covered with a waxy cuticle. 6. The veins of a leaf are made of tissue. 7. The tissue that lies between the two dermal layers of a leaf is called. 8. Stomata and are found on the underside of a leaf. 9. The three leaf characteristics that can be used for plant identification include leaf shape, veins patterns, and the shape of the leaf. Holt McDougal Biology 6 Plant Structure and Function
continued MAIN IDEA: Most leaves are specialized systems for photosynthesis. 10. is the photosynthetic tissue of a leaf. 11. Tall, rectangular mesophyll cells, called mesophyll, absorb much of the light that falls on a leaf. 12. Loosely packed mesophyll cells, called mesophyll, create air spaces that connect with the outside of the plant through stomata. 13. Leaf adaptations that help plants survive in dry or cold environments include cactus spines that reduce water loss, thick leaves that store water, and very thick. Vocabulary Check Fill in the blank with the word or phrase that is described by the sentence. 14. Like the part of a knife with the same name, this is the widest part of a leaf. 15. Found on the underside of a leaf, this guards the exchange of gases through stomata 16. This term means stalk or leafstalk. 17. This term means middle leaf, which is where it is found. Holt McDougal Biology 7 Plant Structure and Function
Holt McDougal Biology 8 Plant Structure and Function