By: Marta Hempel
Curriculum Expectations
F2.1 Use appropriate terminology related to plants, including, but not limited to: mesophyll, palisade, aerenchyma, epidermal tissue, stomata, root hair, pistil, stamen, venation, auxin, and gibberellin.
F2.2 Design and conduct an inquiry to determine the factors that affect plant growth (e.g., the effects on plant growth of the quantity of nutrients, the quantity and quality of light, and factors such as temperature and water retention or percolation rate).
F2.3 Identify, and draw biological diagrams of, the specialized plant tissues in roots, stems, and leaves (e.g., xylem, phloem), using a microscope and models.
F3.1 Describe the structures of the various types of tissues in vascular plants, and explain the mechanisms of transport involved in the processes by which materials are distributed throughout a plant (e.g., transpiration, translocation, osmosis).
F3.4 Describe the various factors that affect plant growth (e.g., growth regulators, sunlight, water, nutrients, acidity, tropism).
F2.2 Design and conduct an inquiry to determine the factors that affect plant growth (e.g., the effects on plant growth of the quantity of nutrients, the quantity and quality of light, and factors such as temperature and water retention or percolation rate).
F2.3 Identify, and draw biological diagrams of, the specialized plant tissues in roots, stems, and leaves (e.g., xylem, phloem), using a microscope and models.
F3.1 Describe the structures of the various types of tissues in vascular plants, and explain the mechanisms of transport involved in the processes by which materials are distributed throughout a plant (e.g., transpiration, translocation, osmosis).
F3.4 Describe the various factors that affect plant growth (e.g., growth regulators, sunlight, water, nutrients, acidity, tropism).
Learning Goals
Students will ...
1. Use appropriate terminology to identify various anatomical plant structures.
2. Use a microscope and models to identify specialized tissues in the roots, stems, and leaves of plants.
3. Draw biological diagrams of specialized plant tissues.
4. Design and conduct an experiment to determine the factors that affect plant growth.
5. Name the structures of vascular plants and the mechanisms that are involved in transporting materials throughout
the plants.
6. Describe the factors that affect plant growth.
1. Use appropriate terminology to identify various anatomical plant structures.
2. Use a microscope and models to identify specialized tissues in the roots, stems, and leaves of plants.
3. Draw biological diagrams of specialized plant tissues.
4. Design and conduct an experiment to determine the factors that affect plant growth.
5. Name the structures of vascular plants and the mechanisms that are involved in transporting materials throughout
the plants.
6. Describe the factors that affect plant growth.
Content
Table of Contents
Plant Tissues
• Epidermis
• Ground Tissues
• Vascular Tissues
• Leaves
- Stomata
• Roots
• Stems
Transport
Growth
• External Factors Affecting Plant Growth
• Soil Nutrients
- Nitrogen Cycle
• Internal Factors Affecting Plant Growth
• Epidermis
• Ground Tissues
• Vascular Tissues
• Leaves
- Stomata
• Roots
• Stems
Transport
Growth
• External Factors Affecting Plant Growth
• Soil Nutrients
- Nitrogen Cycle
• Internal Factors Affecting Plant Growth
Plant Tissues
Epidermis
The outer cell layer of the plant body is the called the epidermis. The cuticle is a waxy exterior surface on parts of the epidermis that protect against water loss, infection by microorganisms, and restricts gaseous exchange through the epidermal cells.
Ground Tissues
Vascular Tissues
Leaves
Leaves are the major sites of photosynthesis and they contain chlorophyll, the green pigment
necessary to capture light energy.
Mesophyll: The photosynthetic region that consists of parenchyma cells containing many chloroplasts.
Stomata
During photosynthesis, the leaf must acquire a constant supply of carbon dioxide and be able to release the oxygen produced. The exchange of these gases is regulated by tiny pores called stomata (singular: stoma). Stomata are mostly found in the lower epidermis of leaves.
Stomata also allow water vapour to escape from the leaf. The loss of water vapour in plants is called transpiration. When a pair of guard cells contains low levels of water, they go limp and rest against each other, closing the stoma. As water builds up in the leaf tissues, the guard cells swell and open.
Stomata also allow water vapour to escape from the leaf. The loss of water vapour in plants is called transpiration. When a pair of guard cells contains low levels of water, they go limp and rest against each other, closing the stoma. As water builds up in the leaf tissues, the guard cells swell and open.
Roots
- Absorb water and minerals from the soil
- Provide physically support
- Anchor the plant
- Store carbohydrates
The primary root is the first main root which develops from the seed. A secondary root, also called a lateral root, is smaller than the main root and branches from it.
Taproots: a root that increases in diameter, grows downward, and develops small lateral roots.
Fibrous Roots: in grasses and other monocots, the primary root is replaced by adventitious roots and lateral roots that form the fibrous root system.
Root hairs: fine roots that form behind the root tip and increase the root’s surface area for absorption.
Stele: cylinder at the center of the root which contains the vascular tissues, xylem and phloem, and some ground tissue. Secondary growth in roots is associated with an increase in diameter of the vascular cylinder.
Stems
- Provide support for the plant
- A act as a transport link between plant parts
- Store water and carbohydrates
- Can be herbaceous or woody.
Transport
Plants transport nutrients, water, a variety of carbohydrates, and hormones throughout their bodies.
Transpiration: Evaporation of water from leaves reduces the pressure at the top of the plant. If water is available to the roots, water will move up the stems and into the leaves, assisted by capillary action.
Translocation: process where carbohydrates produced by photosynthesis are moved from the leaves to other plant parts through the phloem tissue. The pressure flow hypothesis is the most accepted explanation of translocation. Fluids flow from an area of higher pressure toward an area of lower pressure.
Transpiration: Evaporation of water from leaves reduces the pressure at the top of the plant. If water is available to the roots, water will move up the stems and into the leaves, assisted by capillary action.
Translocation: process where carbohydrates produced by photosynthesis are moved from the leaves to other plant parts through the phloem tissue. The pressure flow hypothesis is the most accepted explanation of translocation. Fluids flow from an area of higher pressure toward an area of lower pressure.
Growth
Meristems - region of plant tissue where cells divide by mitosis.
Apical meristems: meristem at the root tips and shoot tips.
Lateral meristem: cylinders of meristematic tissue within the roots and stems which causes the increase in the diameters of roots and stems. Cambium is another name for a lateral meristem.
Primary growth: growth in the diameters of roots and stems in the first year of a plant’s life and growth in the length of roots and stems throughout the plant's life.
Secondary growth: the result of lateral meristem activity throughout the rest of a plant’s life whereby the diameter of the roots and stems increases.
Secondary growth in the stems of trees occurs after year one and involves the vascular cambium. Cells of the vascular cambium divide by mitosis to produce phloem to the outside and xylem to the inside. The phloem cells tend to crush the fragile phloem cells of the previous years. The xylem cells do not crush earlier xylem cells because they have thicker walls. The oldest xylem is nearest the centre of the stem while the youngest is next to the cambium. The xylem thickens and forms tissue known as wood. Each year a new layer of xylem is added which adds size and strength to the aging stem. Xylem cells produced in the spring tend to grow very large because of the moisture available, but as conditions get drier later in the season xylem cells that get produced are much smaller. One zone of spring xylem plus one zone of summer-fall xylem forms an annual ring. By counting the number of rings,one can tell the age of a tree.
Apical meristems: meristem at the root tips and shoot tips.
Lateral meristem: cylinders of meristematic tissue within the roots and stems which causes the increase in the diameters of roots and stems. Cambium is another name for a lateral meristem.
Primary growth: growth in the diameters of roots and stems in the first year of a plant’s life and growth in the length of roots and stems throughout the plant's life.
Secondary growth: the result of lateral meristem activity throughout the rest of a plant’s life whereby the diameter of the roots and stems increases.
Secondary growth in the stems of trees occurs after year one and involves the vascular cambium. Cells of the vascular cambium divide by mitosis to produce phloem to the outside and xylem to the inside. The phloem cells tend to crush the fragile phloem cells of the previous years. The xylem cells do not crush earlier xylem cells because they have thicker walls. The oldest xylem is nearest the centre of the stem while the youngest is next to the cambium. The xylem thickens and forms tissue known as wood. Each year a new layer of xylem is added which adds size and strength to the aging stem. Xylem cells produced in the spring tend to grow very large because of the moisture available, but as conditions get drier later in the season xylem cells that get produced are much smaller. One zone of spring xylem plus one zone of summer-fall xylem forms an annual ring. By counting the number of rings,one can tell the age of a tree.
External Factors Affecting Plant Growth
- Light
- Carbon dioxide
- Water
- Nutrients
Soil Nutrients
Macronutrients: 9 elements needed in large quantities (>1000 mg/kg of dry mass).
Nitrogen (N), phosphorous (P), potassium (K). Calcium (Ca), magnesium (Mg), sulfur (S), carbon (C), oxygen (O), and hydrogen (H).
Micronutrients: 8 elements needed in smaller amounts (<100 mg/kg of dry mass).
Iron (Fe), chlorine (Cl), boron (B), manganese (Mn), zinc (Zn), copper (Cu), molybdenum (Mo), and nickel (Ni).
Carbon, oxygen, and hydrogen are obtained primarily from carbon dioxide and water.The remaining macronutrients and all eight micronutrients are found as dissolved ions in the soil. In soils, most nutrients are either present in the form of minerals or dead organic matter. Nutrients are released in the form of inorganic ions through the physical and chemical weathering of rocks and the decomposition of organic matter by fungi and bacteria.
Nitrogen (N), phosphorous (P), potassium (K). Calcium (Ca), magnesium (Mg), sulfur (S), carbon (C), oxygen (O), and hydrogen (H).
Micronutrients: 8 elements needed in smaller amounts (<100 mg/kg of dry mass).
Iron (Fe), chlorine (Cl), boron (B), manganese (Mn), zinc (Zn), copper (Cu), molybdenum (Mo), and nickel (Ni).
Carbon, oxygen, and hydrogen are obtained primarily from carbon dioxide and water.The remaining macronutrients and all eight micronutrients are found as dissolved ions in the soil. In soils, most nutrients are either present in the form of minerals or dead organic matter. Nutrients are released in the form of inorganic ions through the physical and chemical weathering of rocks and the decomposition of organic matter by fungi and bacteria.
Nitrogen Cycle
Internal Factors Affecting Plant Growth
Growth and development are also influenced by internal chemical regulators (hormones).
The five hormone groups that exist in most plants are:
Auxins: Both stimulate and inhibit plant growth. Primarily involved in promoting plant cell elongation, apical bud growth, and the growth and ripening of fruit. Lateral bud growth is inhibited by them. Auxins also regulate cell division in the vascular cambium and the dropping of fruit and leaves.
Gibberellins: Promoting cell division and elongation in plant shoots. In some plants they cause the stem to elongate just before the plant flowers. This process, called bolting, produces a long stem that raises the flower up to pollinators and the wind. Dwarf varieties of some plants have a mutated gene which blocks the synthesis of gibberellin. Gibberellins are also used commercially to stimulate seed germination.
Cytokinins: Cytokinins are hormones that stimulate cell division and leaf mesophyll growth. Cytokinins are mostly concentrated in endosperm tissue and young fruit. These hormones are important commercially because they are used in tissue cultures to allow the production of new plants which have the identical genotype as an original, genetically altered cell.
Ethylene: Has a role in fruit ripening. Many fruits begin to produce ethylene gas just before the conversion of starch into sugars which increase the sweetness of the fruit. Ethylene is also related to the colour change and softening of ripening fruit. When growers do not want fruit to ripen in storage or during transport, they keep the fruit in conditions which keep ethylene concentrations low. Ethylene is applied externally when they do want the fruit to ripen.
Abscisic Acid: A growth regulator which acts as an inhibitor. It promotes the closure of stomata, induces seed and bud dormancy, and providing resistance to water stress.
The five hormone groups that exist in most plants are:
Auxins: Both stimulate and inhibit plant growth. Primarily involved in promoting plant cell elongation, apical bud growth, and the growth and ripening of fruit. Lateral bud growth is inhibited by them. Auxins also regulate cell division in the vascular cambium and the dropping of fruit and leaves.
Gibberellins: Promoting cell division and elongation in plant shoots. In some plants they cause the stem to elongate just before the plant flowers. This process, called bolting, produces a long stem that raises the flower up to pollinators and the wind. Dwarf varieties of some plants have a mutated gene which blocks the synthesis of gibberellin. Gibberellins are also used commercially to stimulate seed germination.
Cytokinins: Cytokinins are hormones that stimulate cell division and leaf mesophyll growth. Cytokinins are mostly concentrated in endosperm tissue and young fruit. These hormones are important commercially because they are used in tissue cultures to allow the production of new plants which have the identical genotype as an original, genetically altered cell.
Ethylene: Has a role in fruit ripening. Many fruits begin to produce ethylene gas just before the conversion of starch into sugars which increase the sweetness of the fruit. Ethylene is also related to the colour change and softening of ripening fruit. When growers do not want fruit to ripen in storage or during transport, they keep the fruit in conditions which keep ethylene concentrations low. Ethylene is applied externally when they do want the fruit to ripen.
Abscisic Acid: A growth regulator which acts as an inhibitor. It promotes the closure of stomata, induces seed and bud dormancy, and providing resistance to water stress.
Student Activities
Parts of A Plant Activity
Modify and use the activity in the following link to create an activity where your students have to guess what parts of the plant various food items are. This is a great hook leading into the topic of plant parts, but can also be used as an assessments where students are required to apply their knowledge.
Sample
Sample
- Provide approximately 10 samples of different fruits and vegetables listed in the document.
- Place the samples on paper plates distributed throughout your classroom.
- Divide your class into groups and direct each group to one of the fruit/vegetable stations.
- Have the groups analyze the fruits and vegetables at their stations in order to fill out the activity worksheet.
- Have the groups rotate through the stations until they have had a chance to visit each one.
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Build-A-Tomato-Plant Simulation
Plant Hormone Activity
Have your students read the textbook and their notes on plant hormones to complete the provided worksheet.
plant_hormones_activity.docx | |
File Size: | 38 kb |
File Type: | docx |
Online Resources
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Assessment Tools
Plant Growth Lab
Have your students design and conduct their own lab to determine the different factors that affect plant growth.
Factors that you may have your class focus on are:
A sample lab can be found on the bellow link.
http://www.nuffieldfoundation.org/practical-biology/investigating-effect-minerals-plant-growth
Factors that you may have your class focus on are:
- quantity of nutrients
- quantity of light
- quality of light
- temperature
- percolation rate
- quantity of water
- quality of water
A sample lab can be found on the bellow link.
http://www.nuffieldfoundation.org/practical-biology/investigating-effect-minerals-plant-growth
factors_plant__growth_lab.doc | |
File Size: | 41 kb |
File Type: | doc |
Plant Structure Quiz
plant_structure_quiz.docx | |
File Size: | 247 kb |
File Type: | docx |
Glossary
Annual Ring - One zone of spring xylem plus one zone of summer-fall xylem found in woody plants.
Apical meristems - regions at the tips of all roots and shoots responsible for the primary growth, which lengthens shoots and roots.Capillary action -
Cuticle - waxy exterior surface on parts of the epidermis. Epidermis - the outermost cell layer of a plant experiencing primary growth.
Fibrous Roots - in monocots the primary root is replaced by adventitious roots and lateral roots to form the fibrous root system.
Lateral meristems - cylindrical regions in roots and stems responsible for all increases in diameters of the roots and stems.
Macronutrients - 9 elements needed in large quantities (>1000 mg/kg of dry mass) by plants.
Meristem - regions of a plant where cells retain the ability to divide repeatedly by mitosis.
Mesophyll - region of photosynthetic cells between the epidermal layers of leaves.
Micronutrients - 8 elements needed in smaller amounts (<100 mg/kg of dry mass) by plants.
Primary growth - all plant growth originating at the apical meristems resulting in increases in length, as well as growth originating at the lateral meristems in the first year of a plant’s life.
Primary root - the first main root which develops from a seed.
Root Hair - Hairlike structures found on roots that allow for a much larger surface area for water to be absorbed and used by the plant.
Secondary growth - plant growth originating at lateral meristems which results in increased diameters of roots and stems in the second and all subsequent years of a plant’s life.
Secondary root (lateral root) - smaller than the main root and branches out from it.
Stele: cylinder at the center of the root which contains the vascular tissues, xylem and phloem, and some ground tissue.
Stomata - A tiny pore in a plant leaf surrounded by a pair of guard cells that regulate its opening and closure, and serves as the site for gas exchange.
Taproots - a root that increases in diameter, grows downward, and develops small lateral roots.
Transpiration - The loss of water vapor in plants.
Translocation - process where carbohydrates produced by photosynthesis are moved from the leaves to other plant parts through the phloem tissue.
Vascular cambium - a lateral meristem which is responsible for creating new xylem and phloem tissue.
Apical meristems - regions at the tips of all roots and shoots responsible for the primary growth, which lengthens shoots and roots.Capillary action -
Cuticle - waxy exterior surface on parts of the epidermis. Epidermis - the outermost cell layer of a plant experiencing primary growth.
Fibrous Roots - in monocots the primary root is replaced by adventitious roots and lateral roots to form the fibrous root system.
Lateral meristems - cylindrical regions in roots and stems responsible for all increases in diameters of the roots and stems.
Macronutrients - 9 elements needed in large quantities (>1000 mg/kg of dry mass) by plants.
Meristem - regions of a plant where cells retain the ability to divide repeatedly by mitosis.
Mesophyll - region of photosynthetic cells between the epidermal layers of leaves.
Micronutrients - 8 elements needed in smaller amounts (<100 mg/kg of dry mass) by plants.
Primary growth - all plant growth originating at the apical meristems resulting in increases in length, as well as growth originating at the lateral meristems in the first year of a plant’s life.
Primary root - the first main root which develops from a seed.
Root Hair - Hairlike structures found on roots that allow for a much larger surface area for water to be absorbed and used by the plant.
Secondary growth - plant growth originating at lateral meristems which results in increased diameters of roots and stems in the second and all subsequent years of a plant’s life.
Secondary root (lateral root) - smaller than the main root and branches out from it.
Stele: cylinder at the center of the root which contains the vascular tissues, xylem and phloem, and some ground tissue.
Stomata - A tiny pore in a plant leaf surrounded by a pair of guard cells that regulate its opening and closure, and serves as the site for gas exchange.
Taproots - a root that increases in diameter, grows downward, and develops small lateral roots.
Transpiration - The loss of water vapor in plants.
Translocation - process where carbohydrates produced by photosynthesis are moved from the leaves to other plant parts through the phloem tissue.
Vascular cambium - a lateral meristem which is responsible for creating new xylem and phloem tissue.
Resources
All pictures and diagrams on this site, unless otherwise notes, were taken from:
Ritter, Bob, Christine Adam-Carr, and Douglas Fraser. Nelson Biology 11. Upper Saddle River: Nelson Education Limited, 2001. Print.
Ritter, Bob, Christine Adam-Carr, and Douglas Fraser. Nelson Biology 11. Upper Saddle River: Nelson Education Limited, 2001. Print.