Stems & Leaves

Brooke & Becca (TL) May 24th 10:05­10:55 am

Introduction

Introduce Becca to the group Remind of class rules (raise hand for questions, comments) Introduce topic as stems & leaves

Objectives

1. Students will be able to describe the process of photosynthesis. 2. Students will be able to identify the major functions of the stem and the major functions

of the leaf to support the plant through the life cycle. Icebreaker

Review definitions/concepts from previous lessons. Write terms of flip chart and definitions on index cards.

Work in groups of 3 to match index card word to definition on flip chart. Xylem: Part of the root that delivers water and nutrients to the stem Taproot: A type of root that stores a lot of food for the plant, like a carrot Fibrous Root: The type of root a tree has that creates a large network

underground Nitrogen: a nutrient plant get from the air and the soil that is part of chlorophyll

and needed for photosynthesis Root Cap: the tip of a plant’s root that protects it from damage as it grows Root Hair: Small structures on the roots that draw in water and minerals from the

soil Go over answers and allow students to read their answers to the class if they want to.

Content

1. Begin by looking at our seeds that we planted last week (5 mins) pass back handouts and plants

a. Which stage of the life cycle are they in now? How can you tell? What are you observing? What has changed since last week? i. Record in journal.

2. Types of stems a. Soft ­usually green & able to bend b. Woody­ hard, covered in bark and not green/ don't have chlorophyll c. What types of stems are growing from our pea plants?

3. Parts of the Stem a. Xylem: moves water and minerals up to the leaves (we talked about this last

week and it was in the review activity) b. Phloem: moves food (sugar/glucose) to feed the rest of the plant after leaves

undergo photosynthesis c. Fun way to remember these words: “xy” goes up toward the “sky”, “phlo” flows

down toward the ground 4. Functions of Stems

a. Just like we talked about with roots, the stems and the leaves of the plant have certain jobs that are important for the health and growth of the plant to support it through its life cycle

b. Plant support system i. Hold leaves up to the sun ii. Hold fruit and flowers in place

c. “Nutrient Highway” between roots and leaves (phloem & xylem) 1. Transports water & nutrients from soil like we discussed last class 2. Two way road → xylem going toward leaves, phloem going

toward roots a. Think about what happens when you don't water a plant.

What parts do you see die/wilt first? 5. Stems We Eat

What are some types of stems that we eat? Can you think of any? a. Celery, asparagus, rhubarb (have pictures to pass around) b. Celery Activity

i. What do you think will happen to the celery? Activity: Water movement experiment Materials needed: celery, containers, water, food dye 1. Show celery with leaves still in tact in cup with food dye (2) 2. Ask class what they think will happen to the leaves and to the stem of the celery 3. Pass around celery that has already sat overnight in the dye and show how the leaves have changed color and the xylem are colored when you look at the base of the stem

4. We are able to see the water moving up through the stem and into the leaves since it is colored.

5. Types of Leaves

a. Simple leaf: leaf with only one blade b. Compound leaf : leaf with more than one blade c. Allow the students to identify which types of leaves the images on the flipchart

are d. What types of leaves are on your pea plant?

6. Parts of the Leaf a. Blade: broad flat area, most of the leaves area b. Tip: tip of the leaf c. Vein: carry water and nutrients within a leaf, supports structure of the leaf

i. Can you see these on your pea leaves? ii. What do veins do in humans? iii. Similar to our vascular system → carries fluid, blood, and nutrients

through our bodies d. Petiole:stem like part of the leaf that connects the blade to the stem; extension of

the xylem and phloem tubes of the stem (aka secondary stems) i. Similar to the roots’ lateral roots that came off the primary root ii. Deliver water and nutrients into the vein of the leaf so they can spread

throughout the rest of the blade e. Stipule: two small flaps that grow at the base of the petiole

i. In many plants the stipules drop off after the blade has developed, but garden peas and a few other kinds of plants have large stipules that serve as an extra food­producing part of the leaf.

f. Stomata: takes in CO2, gives off O2 (microscopic pores in the blade) i. The stomata are so small that we cannot see them ii. They are throughout the blade taking in water and oxygen and releasing

carbon dioxide iii. They are similar to the pores in our skin iv. When a plant is left in the sun on a hot day the leaves will wilt because it

is losing water through the stomata

7. Functions of Leaves a. Food making Factory

i. Plants are adapted to making their own food, unlike animals & humans who have to eat plants & animals to get energy

ii. Photosynthesis 1. Photo means “light” and synthesis means “putting together” 2. Plants make their own food

a. Chlorophyll is the chemical in leaves that make them green in color. In spring and summer, when there is lots of sunlight, this chemical absorbs energy from the sun. The Stomata takes in CO2 from the air. The light energy from the sun and CO2 from the air are used to make glucose (sugar), the plant’s food.

3. Although animals can eat these plants and use the glucose that they have made for energy, plants make glucose for themselves. Glucose is the food they use to grow and carry out their life processes.

4. Show cycle of how animals, plants, humans, environment are interconnected/interdependent

a. Remind of nutrient cycle from last class, similar concept 5. Can anyone raise their hand and share a food that is the leaf of

the plant?

b. Leaves come in all different shapes/sizes to suit their environment & needs i. Give examples (i.e. desert plants vs. tropical plants)

1. What kinds of plants grow in the desert? What are their leaves like?

2. Desert plants like cacti don’t have leaves because they would dry out in the hot sun

a. Instead, they have spikes that provide them with shade b. They have extensive root systems so they can get water

from the ground more efficiently c. They store water in their thick stems

3. Tropical plants at the rainforest floor have large leaves because the sunshine and rain is blocked by all of the other plants in the canopy (above the forest floor)

a. The large leaves give them more area to absorb sunlight and water

ii. Show pictures of different types of leaves c. Why do leaves change color in the fall where we live?

i. In the summer, plants get plenty of water and sunlight and all of the extra sugar they make gets turned into starch and is stored within the plant (remind of tap roots from last class)

ii. Not enough light or water in the winter for the plant to undergo photosynthesis ­ days get shorter, ground freezes ­ so they rely on their stored sugar (starch) for food

iii. They lose their chlorophyll and begin change color from green to brown iv. The leaves die and fall off ­ but many plants’ seeds remain underground

and ready to sprout again in the spring when the conditions are good for growing again

8. Leaves That We Eat

a. Pass around pictures of leaves and the names of the leafy vegetables separately (8 of each)

b. Have students with pictures stand in a line at the front of the class c. See if students with the names of the leaves can find their match! d. spinach, cabbage, kale, swiss chard, bok choy, collard greens, romaine,

radicchio e. There are 15 students, so 1 intern will hold a picture since we need an even

number of participants

Activity: Edible leaves and stem. ­Observe different parts of leaves and stem with raw kale and kale chips. ­Don’t forget food safety (hand washing or sanitizing). ­Pass out one of each type of kale to students and encourage them to use good descriptive words like last class. ­Prompt students to fill in final blank of their worksheet (something new you learned today)

Evaluation Students must determine the two parts of the stem, related to their functions. Students must also fill in the blanks of a paragraph describing the process of photosynthesis. Supplies: Index cards w/ definitions for icebreaker activity Tape Pre­colored celery to show 2 cups w/ celery in food dye

Plastic Cups Food Dye 2 stalks celery

Names of edible leaves along w/ pictures Kale chips Raw kale leaves Hand Sanitizer Pictures of desert & tropical leaves New Worksheets Worksheets from last class Key Terms: Xylem Phloem Blade

Tip Vein Petiole Stipule Stomata Chlorophyll Glucose

Resources: http://sciencewithme.com/learn­about­leaves/ http://creatingalearningenvironment.com/10­science­experiments­every­child­should­experience­school­holiday­ideas/ http://www.kcedventures.com/blog/how­do­leaves­breathe­a­simple­science­experiment­for­kids

1. What has changed about your pea sprout? Does it have leaves and a stem? What else do you notice?

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2. Label the two parts of the stem.

The _______________ moves minerals and water from the roots, up the stem

and to the leaves, so they can perform photosynthesis.

The _______________ moves the food made by photosynthesis to the rest of the

plant.

Name: _____________________________________

Minerals and Water

Food (Glucose)

3. Using the word back and the diagram fill in the blanks. Photosynthesis is a process where the ________________ of plants use

_________________ from the sun to convert _______________________

from the air and ___________________ from the soil into _________________

to feed the plant and _____________________ is released into the air.

WORD BANK

Water, glucose, carbon dioxide, light, oxygen, leaves

4. Edible leaf observations: Observation Question: Raw Kale Kale Chip

What does the food look like?

What is the texture like?

What does it taste like?

Examples of describing words: crispy, crunchy, lumpy, soft, silky, smooth, rough, sweet, bitter, salty, green, black, brown, other colors, shiny. 5. What is one new thing you learned today?

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Leaves That We Eat

Spinach Romaine Lettuce

Kale

Basil