Ac vi es:

A. Beginning

1. Gree ngs

2. Administra ve business – roll call, etc. (performed internally)

3. Reflec on - Ocean: origin of life

4. The teacher will ask the students to look at the Venn diagram assigned the previous day so they can review the subject. The teacher will discuss the differences between terrestrial grasses, seagrasses and marine algae. The similari es should be highlighted, since students must carefully analyze what they studied during the previous class so they can describe these similari es.

B. Development

1. A er the discussion, the teacher will ask students to build a meline describing the evolu on of seagrasses. To do this, the group will be divided into 4 or 5 subgroups. Each group will receive a piece of paperboard or brown paper and several pictures of the organisms shown at each period (if copies cannot be made, the teacher can place the pictures on the board so students can see them and capture the details in their own drawings). Students will be asked to use their paperboard or brown paper to draw a meline with the different geologic me periods important to plant evolu on, which are:

 Precambrian Era: The beginning of this era gave rise to phytoplankton, while mul cellular algae developed near the end of the era. The Precambrian occurred between 4,500 to 500 million years ago, approximately.

 Silurian Period: Algae dominated during this period, although terrestrial plants began developing. This period occurred approximately 450 million years ago.

 Devonian Period: The first true trees with fruits (gymnosperms) appeared. This period occurred approximately 416 million years ago.

 Cretaceous Period: This period saw the rise of angiosperms (flowering plants) and, at the end, mangroves, and seagrasses. This occurred approximately 145 million years ago.

Note: These are not all the periods that occurred during Earth’s history. For this class, only the most per nent periods will be studied, as these were the me periods in which seagrasses evolved.

The instructor will issue students the following instruc ons:

• Draw a line on the paperboard or brown paper.

• Divide this line in the following geologic era and periods: Precambrian Era, Silurian Period, Devonian Period, and Cretaceous Period.

• Then, on each era or period, the students will draw or a ach the pictures of the organisms they think evolved in that me period. To do this, they must analyze the events occurring during these me periods. The teacher will project these historic events on the board.

• When finished, students will a ach their melines on the wall for their classmates to see.

Note: The historic events the teacher will project on the board and the pictures of organisms used to complete the meline can be found in the CD-ROM included with this guide.

Second op on to make the meline

Schools that have the available technology can use several accessible, free programs such as Cronos. They can also use Microso Word, an Excel template, or a PowerPoint add-in (for versions previous to 2013) that can be downloaded for free through the internet. The 2013 PowerPoint program can use a meline template that is already included in the program. Here, we provide a list of some online services that provide meline drawing services; most, for free: h p://www.office meline.com/download.aspx#Download – Add-in to make PowerPoint timelines. h p://www.so schools.com/teacher_resources/ meline_maker/ h p://www.teach-nology.com/web_tools/materials/ melines/ h p://www. ki-toki.com/ h p:// meglider.com/ h p://www.capzles.com/ h p://www.ourstory.com/ h p:// melinemaker.office meline.com/ h p://www.dipity.com/ h p://www. metoast.com/ h p://www.simile-widgets.org/ meline/ h p://www.rememble.com/ h p:// merime.com/es/ h p://www.preceden.com/

Note: Neither the Sea Grant Program nor the University of Puerto Rico sponsor any brand or program in par cular.

Third op on to make the meline

If none of the previously-men oned op ons is available, the teacher can print or copy the meline included in the guide’s CD-ROM and hand it out to the students so they can complete their meline.

2. A er each sub-group displays their melines for the rest of the class to observe, the teacher will discuss them with the group. They can be asked about why they drew their melines the way they did, and while they jus fy their choices, discuss and review how seagrasses evolved and how they have adapted for survival.

3. At the end of the discussion, the teacher can show the Seagrass meadows PowerPoint presenta on included in the CD-ROM. Their evolu on is presented there, and the student will be able to see which group was the closest to reality. Then, using what they have learned in class, students will be allowed to fix their meline and rearrange it into the correct order before submi ng it for their final scores.

4. A er discussing these plants’ evolu on, the teacher will use the Seagrass meadows PowerPoint presenta on to show the students the different species of seagrass found in Puerto Rico and their characteris cs. This presenta on shows pictures of five (5) seagrass species. Although there are five species found in Puerto Rico, special emphasis will be given to the four (4) most common types.

Note: The teacher must know these characteris cs fully in order to have an effec ve class discussion. Please see the seagrass background sec on.

E. Closing

1. To conclude the class, students will be provided with a sheet showing several pictures of seagrasses commonly found in Puerto Rico. They will be asked to use what they have learned to iden fy the different species according to the characteris cs of their leaves.

Note: The photographs of the seagrass species have been enlarged so that students can see the finer details of their physical characteris cs. However, it is worth men oning that seagrasses greatly differ in terms of blade length and thickness. These can be very short or long, and thick or very thin.

Main characteris cs found in seagrass leaves:

Turtle grass (Thalassia testudinum): The leaves are flat, long, and ribbon-shaped. The leaf p is rounded.

Manatee grass (Syringodium filiforme): The leaves are cylindrical, fine, and elongated, like spaghe strands.

Shoalgrass (Halodule wrigh i): The leaves are long and flat, while the ps are pointed, with two or three peaks.

Paddle grass (Halophila decipiens): The leaves are small, flat, and oval-shaped. The leaves look like small oars or paddles.

2. Clear up any remaining doubts and ques ons about the topic.

Homework:

1. Students will be asked to write a comic strip summarizing what they have learned in class. To do this, they can use a website like ToonDoo.com or any other site such as:

StripGenerator

Pixton

Marvel Superhero Squad

Dilbert

ComicMaster h p://toonlet.com/ h p://goanimate.com/- animated comic strip h p://www.makebeliefscomix.com/

If students do not have access to a computer to make the comic strip, they can draw it.

If the strips are made digitally, they can be sent to the teacher via e-mail to be projected during the next class. The students that draw their strips should bring them in so the other students can see.

Praxis reflec on:

The reflec on will be performed by the teacher at the end of class.

Reasonable accommoda on:

Reasonable accommoda on will be offered to all students who need it. Students with physical or cogni ve difficul es will be offered reasonable me in which to complete their tasks, tutoring during office hours and all the necessary opportuni es, according to their par cular cases.

Oceanic literacy: Essen al principles and fundamental concepts

Principle 4: “The ocean made the Earth habitable.” b. The first life is thought to have started in the ocean. The earliest evidence of life is found in the ocean.

Principle 5: “The ocean supports a great diversity of life and ecosystems.” d. Ocean biology provides many unique examples of life cycles, adapta ons, and important rela onships among organisms (symbiosis, predator-prey dynamics, and energy transfer) that do not occur on land.

Content standards and grade expecta ons

Biological sciences

Standard: Subject organiza on structure and levels

Expecta ons and indicators:

From molecules to organisms: structures and processes

4.B.CB1.EM.2 Men ons and debates about the func onal advantages of structural adapta ons.

Standard: Conserva on and change

4.B.CB1.CC.1 Defines, iden fies, and uses evidence to prepare arguments regarding the adap ve mechanisms plants and animals develop to survive and react to changes in their environments.

4.B.CB1.CC.2 Recognizes that an organism’s shape, structure, and vital func ons can change across all its developmental stages.

Standard: Subject organiza on structure and levels

Expecta ons and indicators:

From molecules to organisms: structures and processes

5.B.CB1.IE.2 Explains the role plants have played in evolu on.

References:

Merriam-Webster Online Dic onary. (2020). Herb. Retrieved on March 27, 2020. h ps://www.merriamwebster.com/dic onary/herb

Seagrass meadows: Teacher’s Guide 85

Earth is covered by volcanic gases with very little oxygen. The first oceans are formed. The first living organisms appear. Many mountains are formed. This era ends with much more oxygen in the atmo sphere, as well as some multicellular organisms.

Silurian

Silurian Period

The first terrestrial, estuarine and freshwater ecosystems are formed. The first fishes develop. Vast coral reefs take shape. Weather similar to our current weather.

This period is also known as the ‘Age of the Fishes’. There is a great variety of terrestrial invertebrates. This is the period in which life moves onto dry land. Global climate is warm and dry.

MILLIONS OF YEARS AGO

Cretaceous Period

Global warming is extreme. Almost all of Earth has tropical temperatures. The first pollinizing insects appear: bees , wasps, and beetles, among others. The dinosaurs become extinct at the end of the period.

University ofPuerto Rico

MayagüezCampus Sea GrantProgram

Seagrasses Timeline–Seagrass evolution

Name: __________________________Date: _____________________________

Teacher: ___________________________Grade-Group:

Instructions: Write on the horizontal arrows the different geologic periods during which seagrasses evolved. Then, attachthe pictures (provided by the teacher) or draw in each of the squa res the organisms that developed during each period or era. The teacher will use the board to project the historic events happening in each period so that you can determine the correct order in which these organisms appeared.

MesozoicEra

Note: These are not the only geologic eras or periods that occurred; only the ones most relevant to sea grass evolution. PrecambrianEra

PaleozoicEra

University ofPuerto Rico

MayagüezCampus

Sea GrantProgram

Identifythe seagrasses

Name: ____________________________Date: _____________________________

Teacher: __________________________Grade-Group: _______________________

Seagrasses are plants which grow, flower,and live under the sea. They come in different shapes and sizes; these include leaves shaped like spaghetti strands, and long, ribbon-like leaves, just to name a few.

Can you identify the different species of seagrass?

Carefully observe the following pictures and identify the type of seagrass according to the leaves’ characteristics (written on the table). Write the code corresponding to the seagrass on the line below each image. For instance, if the species were manatee grass, write MG on the line, and so forth. Note: The teacher can show the pictures of seagrasses at a larger size so students can appreciate their features.

Seagrass species

TG

MG

SG

PG

Leaf characteristics

Turtle grass (Thalassia testudinum)

Long, flat leaves

Rounded leaf tips

Shaped like a ribbon

Manatee grass (Syringodium filiforme)

Fine, long, cylindrical leaves

Shaped like spaghetti strands

Shoalgrass (Halodule wrightii)

Flat, narrow leaves

Feature two or three points at the end of each leaf

Paddle grass (Halophila decipiens)

Flat, oval-shaped leaves

Leaves grow in pairs

Shaped like a small paddle

Unit: Marine ecosystems

Necessary condi ons for seagrass development

Seagrass distribu on in Puerto Rico and around the world

Time: 1 or more class periods (the teacher will adjust, according to the grade and group)

Teaching strategy: ECA

Phases: conceptualiza on and applica on

Teaching methods: Demonstra ve, exposi onal, inquisi ve, ac on or ac vity

Teaching techniques: review, coopera ve work, discussion, conference, homework

Assessment technique: Open ques ons, digital model (if the technology is unavailable, students can draw it or complete it manually), maps (interac ve or paper-based), comic strip, one-sentence summary.

Integra on with other subjects: Biology, Ecology, Social Studies, Geography, Art

Materials:

• Seagrass meadows - Teacher’s Guide

• Teacher’s Guide CD-ROM

• Slideshow – Seagrass meadows

• Materials for building the model: if using the digital one, they will need a computer and the interac ve document; if comple ng it by hand, they will need poster boards, pa erns, transparent tape and a small cardboard box; if they will be drawing it, they’ll need coloring pencils or crayons along with white or brown paper

• Map of the rivers in Puerto Rico (if the ac vity will be digital, they will need a computer and digital maps)

• World map (if the ac vity will be digital, they will need a computer and digital maps)

Note: All digital materials are included in the CD-ROM included with this guide.

Taxonomy type: N. Webb (2005)

Depth of knowlege levels:

Level I: Memory thinking

Level II: Processing thinking de Level III: Strategic thinking

Level IV: Extended thinking

Objec ves:

A er studying the Necessary condi ons for seagrass development and Seagrass distribu on in Puerto Rico and around the world topics, the student will be able to:

• select the elements necessary for seagrass survival. (procedural)

• explain the necessary condi ons for seagrass development. (conceptual)

• create the necessary environment for seagrass growth. (procedural)

• iden fy the places in Puerto Rico in which seagrass can thrive. (procedural)

• use the knowledge acquired to predict the places around the world in which seagrasses grow and develop. (procedural)

• appreciate and conserve the seagrass ecosystem. (a tudinal)