Lesson Plan of Internal Structure of Leaf
General Science Grade VI
Students’ Learning Outcomes
· Describe the internal structural of leaf.
Information for Teachers
· In plants, leaves are the major site of photosynthesis.
· They are often referred as food factories of nature.
· A leaf is made up of many layers those are sandwiched between two layers i.e. the upper epidermis and lower epidermis.
· The upper epidermis is covered by waxy cuticle which reduces evaporation from the upper surface and lower epidermis has stomata pores for exchange of gases.
· Palisade mesophyll cells are tightly packed elongated cells where most food production takes place.
· Spongy mesophyll cells are loosely packed with large intercellular spaces, where the exchange of gases takes place more efficiently.
· Conducting tissues consist of xylem and phloem.
· Xylem transport water and minerals and phloem transport food to other parts of plant.
· Midrib Veins
Material / Resources
Different leaves, chart showing the internal structure of leaf, prepared slide showing Transverse section of leaf, microscope.
Worm up activity
· Bring some leaves to the class.
· Show them to the students and ask the following questions.
o What is the role of a leaf in a plant?
(Expected response: to prepare food)
o Why is the color of a leaf green?
(Expected response: due to chlorophyll)
o Name the structures visible on the surface of the leaf?
(Expected response: Lamina and midrib)
· Facilitate the students to get to the right response and then introduce the today’s topic.
· Show the students a prepared slide of the internal structure of a leaf under the microscope.
· Display a chart showing a diagram of the internal structure of a leaf.
· Ask the students to observe the chart showing the diagram of the internal structure of a leaf and observe the prepared slide under the microscope one by one.
· Ask them to compare the internal parts of the T.S of a leaf with the diagram displayed on the chart.
· Now explain the parts of the internal section of a leaf as shown on the chart and explain the function of each part.
· During the activity, ask the students to observe the chart of the internal structure of leaf.
· Draw the internal structure of leaf on board and explain the role of stomata, mesophyll tissues, xylem, phloem and cuticle.
· Explain how the internal and external structure of leaf facilitates photosynthesis.
· Draw the figure as given below, on board and ask the students to complete these boxes by suitable answers.
v Carbon dioxide
v Sun light
Structure of Leaf
Sum up / Conclusion
· Repeat the important points of the lesson by involving the students as:
· A leaf consists of many layers i.e. cuticle, upper and lower epidermis, mesophyll tissues (spongy and palisade), conducting tissues (Xylem and phloem) which perform different functions. In most plants photosynthesis takes place in the leaf. Leaves are often referred as food factories.
· Make a line drawing on the board to show the internal structure of the leaf and label it 1-9 as given in the diagram
· Draw a table on the board as shown
· Fill it by the responses of the students and ask them to copy on their note books.
Structure of Leaf
· Write the following questions on the board and ask them to copy and solve as home work on their notebooks.
o How Lamina can help in photosynthesis?
o Does the arrangement of leaves, play any role in photosynthesis?
o What is the role of stomata in photosynthesis?
o Why more chloroplasts are present in palisade tissues rather than the spongy mesophyll tissues?