Activity
Leaf Structure and Function
In this activity, students with visual impairments compare the structure and function of broadleaf leaves and pine needles.
Students with visual impairment should be introduced to the natural world with real objects when at all possible. This activity allows students to observe both real objects to represent types of leaves and tactile graphics of the leaves.
Related vocabulary:
- cone – reproductive structure of coniferous trees
- coniferous trees – a tree which has cones and needles rather than broad leaves, usually evergreen
- broadleaf – a tree or plant with flat, wide leaves, usually deciduous
- evergreen – tree which has leaves which remain green throughout the winter
- deciduous – tree which loses its leaves in the winter
Materials
- Prepare pine needles if available in your area. A new broom may be used to remove the “needles” as a model if there are not pine needles nearby.
- Pine cones – If not available naturally in your area, buy cones at a craft store.
- APH Sense of Science – Plants Kit – Tactile graphic or colored image of a leaf
- APH Basic Science Tactile Graphics – Leaf shapes tactile graphic – Unfortunately, there is not a large print version in this set.
- APH Tactile and Visual Globe for each student
For Students with Low Vision:
Preparation
- Remove the “Leaf” raised line and picture from the APH Sense of Science Plant kit
- Set up the light box or Mini-lite box if working with a low vision student.
Procedure
When students arrive in class, have pine needles and the tactile graphic of a large leaf from the APH Sense of Science Plants Kit for each student on the desk.
- Ask students: Do you recognize these types of leaves? Discuss how the leaves are different in shape – broad and flat versus needle-like. Consider surface area.
- Ask: What benefit might leaves with this needle-like structure provide for trees?
- Discuss: Trees with this type of leaf can survive in cold, dry climates because they can retain water better than broadleaf trees and won’t freeze as easily. Where would you expect these types of trees to be in the world? In the United States?
- Coniferous trees are more suited for cold and dry climates. Most are evergreen meaning that they don’t lose their leaves (needles) in the winter They are in fact found in the US only in the NE of the country and are found mostly in regions of the world that are N of the United States. Use the APH Tactile and Visual Globe to describe the location of coniferous forests.
- Ask: What type of tree has this needle-like leaf?
- Discuss: coniferous evergreen trees
- Show students examples of cones.
- Ask: Do trees with cones have flowers? Discuss (No they don’t)
- Ask: Why not? Discuss cones
- Discuss the function of cones: reproduction
- Closure: Students will review vocab words.
Variations
If you have coniferous trees in your area, go and find specimens prior to this activity with the students.
NGSS Standards:
Middle School – Structure and Function
LS1.A: Structure and Function
- Systems of specialized cells within organisms help them perform the essential functions of life. (HS-LS1-1)
- All cells contain genetic information in the form of DNA molecules. Genes are regions in the DNA that contain the instructions that code for the formation of proteins, which carry out most of the work of cells. (HS-LS1-1) (Note: This Disciplinary Core Idea is also addressed by HS-LS3-1.)
- Multicellular organisms have a hierarchical structural organization, in which any one system is made up of numerous parts and is itself a component of the next level. (HS-LS1-2)
By Laura Hospitál
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