Diversity of Life: Investigation 6: Transpiration

Focus Question: What happened to the water in the vials?

Procedure, Part 1:

  1. Write the focus question and copy the data table in your notebook.

Celery condition / Starting volume of water (mL) / Ending volume of water (mL) / Change / Starting mass of celery (g) / Ending mass of celery (g) / Change
  1. Fill in the data from yesterday:
  2. celery condition (with leaves or without leaves)
  3. the starting volume of water
  4. the starting mass of celery
  1. Measure the volume of water using a graduate cylinder and the mass of the celery using a scale. Record in the “ending” columns on the data table. Calculate the changes.
  1. Discuss the results with your partner. Where did the missing water go?

Procedure, Part 2:

  1. Observe the celery in the red water. What do you notice?
  1. Cut a thin cross section of the celery stalk and observe with a hand lens or microscope.
  1. Discuss with your partner how your observations might help you explain the movement of water in the celery.
  1. Answer the focus question in your notebook. Use evidence from the data table and a diagram to explain what happened to the water in the vials.

Language Objective:

Students will observethe process of transpiration, by measuring and comparingthe amount of water missing from vials with different conditions of celery, build an explanation and a model to describe the transport of water in plantsand provide evidencefrom the data chart.

English Language Development:

  • Use a pictorial to explain to students that the tubelike structures that carry water from the roots through the plant are called xylem. Xylem is made of specialized long, thin cells stuck end to end to form the water transportation system of most land plants.
  • Explain that through evaporation and the cohesive property of water, water is pulled up from the roots through the xylemto the leaves of the plant.
  • Students draw the diagram in their notebook and then take turns explaining to their partners how the process of transpiration relates to the celery investigation.
  • Students then draw a line-of-learning under their focus question answer and add new ideas about transpiration using the vocabulary words from the pictorial.

Essential Question: What are water’s unique physical and chemical properties?

Application at Grade 7: How does water move through vascular plants? How does water interact with living things?

TEKS for Life Science:

  • investigate and explain how internal structures of organisms have adaptations that allow specific functions such as gills in fish, hollow bones in birds, or xylem in plants;
  • differentiate between structure and function in plant and animal cell organelles, including cell membrane, cell wall, nucleus, cytoplasm, mitochondrion, chloroplast, and vacuole;
  • observe and describe how different environments, including microhabitats in schoolyards and biomes, support different varieties of organisms

TEKS for ELL’s:

  • Vocabulary needs to be taught in the context of connected discourse so that language is meaningful;
  • At the same time ELL’s are learning in English, the focus is on academic English, concepts, and the language structures specific to the content.

Velez & Vargas LHS 2011