Earth and Life Science Quarter 1 Module 14: Geologic Timeline

Earth and Life Science Quarter 1 – Module 14: Geologic Timeline

Senior High School

[illustration: students studying outdoors under a tree, a teacher helping students at a desk, a child working by a lamp, and a globe]

CO_Q1_ELS SHS Module 14

Earth and Life Science Alternative Delivery Mode Quarter 1 – Module 14: Geologic Timeline First Edition, 2021

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Published by the Department of Education
Secretary: Leonor Magtolis Briones
Undersecretary: Diosdado M. San Antonio

Development Team of the Module

Writer: Christian Jay D. Salazar

Editors: Melanie I. Samudio
Jocelyn M. Manset

Reviewers: Jason Ricaforte, Angelica Beriña, Princess Paolah L. De Guzman, Marissa C. Betchaida, Louie L. Alvarez, Gregorio M. De Chavez, Jr., Jocelyn M. Manset, Mario B. Maramot, Elaine T. Balaogan, Job S. Zape Jr., Jonathan V. Mayo

Illustrator: Ednelinda Robles, Lovely Joy La Rosa, Charles Erick A. Jusay, Sandro Carlo B. Tablizo

Layout Artist: Elizalde L. Piol, Anselma M. Ebero, Jocelyn M. Manset

Management Team: Francis Cesar B. Bringas
Job S. Zape, Jr.
Ramonito Elumbaring
Reicon C. Condes
Elaine T. Balaogan
Fe M. Ong-ongowan
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Nadine C. Celindro
Nicolas M. Burgos
Mario B. Maramot
Fe M. Ong-ongowan
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Earth and Life Science Quarter 1 – Module 14: Geologic Timeline

Senior High School

Introductory Message

This Self-Learning Module (SLM) is prepared so that you, our dear learners, can continue your studies and learn while at home. Activities, questions, directions, exercises, and discussions are carefully stated for you to understand each lesson.

Each SLM is composed of different parts. Each part shall guide you step-by-step as you discover and understand the lesson prepared for you.

Pre-tests are provided to measure your prior knowledge on lessons in each SLM. This will tell you if you need to proceed on completing this module or if you need to ask your facilitator or your teacher’s assistance for better understanding of the lesson. At the end of each module, you need to answer the post-test to self-check your learning. Answer keys are provided for each activity and test. We trust that you will be honest in using these.

In addition to the material in the main text, Notes to the Teacher are also provided to our facilitators and parents for strategies and reminders on how they can best help you on your home-based learning.

Please use this module with care. Do not put unnecessary marks on any part of this SLM. Use a separate sheet of paper in answering the exercises and tests. And read the instructions carefully before performing each task.

If you have any questions in using this SLM or any difficulty in answering the tasks in this module, do not hesitate to consult your teacher or facilitator.

Thank you.

What I Need to Know

This module was designed and written with you in mind. It is here to help you master the nature of Biology. The scope of this module permits it to be used in many different learning situations. The language used recognizes the diverse vocabulary level of students. The lessons are arranged to follow the standard sequence of the course. But the order in which you read them can be changed to correspond with the textbook you are now using.

The module covers:

• Lesson 1 – Geologic Timeline

After going through this module, you are expected to:

1. Describe how the Earth’s history can be interpreted from the geologic time scale.
2. Define fossils and its type.
3. Determine the guide fossils that are used to define and identify subdivision of the geologic time scale.
4. Track the Earth’s history using the geologic time scale.
5. Identify the different divisions in the geologic time scale.

What I Know

Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper.

1. Which of the following does NOT belong to Paleozoic Era?

   • A. Cambrian
   • B. Devonian
   • C. Jurassic
   • D. Ordovician

2. What do you call the remains or evidence used as markers when building up the geologic time scale?

   • A. fossil
   • B. minerals
   • C. piles of rock
   • D. sandstone

3. Why do most of the eons and eras end in “zoic”?

   • A. because these time periods were recognized by the plants present at that time
   • B. because these time periods were recognized by the animal life present at that time
   • C. A and B
   • D. none of the above

4. In what type of rocks are fossils made up of?

   • A. igneous rock
   • B. metamorphic rock
   • C. sedimentary rock
   • D. all of the above

5. What do you call the person who studies fossils and ancient life?

   • A. anthropologist
   • B. archeologist
   • C. biologist
   • D. paleontologist

6. What do you call the process by which the remains of ancient living things are turned into rock?

   • A. fertilization
   • B. fossilization
   • C. fragmentation
   • D. metamorphosis

7. How were the scientists able to arrange the fossils they gathered?

   • A. They were able to arrange the fossils according to age.
   • B. They were able to arrange the fossils according to structure.
   • C. They were able to arrange the fossils according to chemical content.
   • D. They were able to arrange the fossils according to place of discovery.

8. In what era did the rocks with fossils of animals and plants such as dinosaurs, mammals, and trees form?

   • A. Cenozoic Era
   • B. Mesozoic Era
   • C. Paleozoic Era
   • D. Phanerozoic Era

9. In what era did the first skeletal elements, soft-bodies metazoans, and animal traces exist?

   • A. Cenozoic Era
   • B. Late Proterozoic
   • C. Mesozoic Era
   • D. Paleozoic Era

10. What period the first mammals and dinosaurs existed?

    
    

• A. Cretaceous
• B. Jurassic
• C. Permian
• D. Triassic

11. In Paleozoic Era, in what period did the first vascular land planet exist?

• A. Cambrian
• B. Devonian
• C. Ordovician
• D. Silurian

12. These marine animals lived inside their shells, taking up the whole inside of the long shell.

• A. echinoderms
• B. gastropods
• C. mollusks
• D. sea arthropods

13. In what phylum do crinoids belong?

• A. echinoderms
• B. arthropods
• C. gastropods
• D. mollusks

14. What do you call the marine arthropods that were made of chitin, like some insects and other organisms like lobsters?

• A. crinoids
• B. fossil clam
• C. gastropods
• D. trilobites

15. Which of the following marine animals are bivalves with two symmetrical shells – the shells are mirror images of each other?

• A. crinoids
• B. fossil clam
• C. gastropods
• D. trilobites

Lesson 1 Geologic Timeline

Fossils are the remains or evidence of prehistoric plants and animals that have fossilized. Fossils were used as markers when building up the geologic time scale. The names of most of the eons and eras end in “zoic”, because these time periods were recognized by the animal life present at the time. Rocks formed during the Proterozoic Eon have fossil evidence of simple organisms, such as bacteria, algae, and wormlike animals. In the Phanerozoic Eon, the rocks formed have fossils of animals and plants such as dinosaurs, mammals, and trees.

And with that, geologists have developed the geological time scale, which divides the Earth’s history into eons that are subdivided into eras, which are further divided into periods and then into epochs. The geologic time scale is the “calendar” for events in Earth’s history. It subdivides all time since the end of the Earth’s formative period as a planet (nearly 4 billion years ago) into named units of abstract time: in descending order of duration, which are eons, eras, periods, and epochs.

The geologic time scale provides a system of chronologic measurement relating stratigraphy to time that is used by geologists, paleontologists, and other Earth scientists to describe the timing and relationships between events that have occurred during the history of the Earth. The detailed studies made of rocks throughout the world have allowed geologists to correlate rock units globally, and break them into time units. The result is the Geologic Time Scale, usually presented in a chart like form with the oldest event and time unit at the bottom and the youngest at the top.

What’s In

Activity 1

Review the vocabulary words and complete the activity on the other side of this worksheet.

1. Fossils – remains of ancient life that have been turned to stone
2. Body Fossils – actual parts of plants and animals that have been turned to stone (i.e. bone, shells, leaves)
3. Coprolite – fossilized dinosaur dung (scat)
4. Fossilization – process by which the remains of ancient living things are turned to rock
5. Paleontologist – a scientist who studies fossils and ancient life
6. Sedimentary Rock – rock made of layers of tightly packed sand and clay

[transcriber’s note: the heading for the activity that these vocabulary items and fill-in-the-blank passage belong to is not on this page]

7. Sandstone – a type of sedimentary rock that is made of sand
8. Trace Fossil – a fossilized sign that a plant or animal once lived in an area (i.e. footprints, coprolite)
9. Porous – full of tiny holes that water, air, and light can pass through
10. Mineralization – to convert into a mineral substance; to fill with a mineral substance

Instructions: Fill in the blanks, using vocabulary words.

Jay, a famous p _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ t, was hiking in the Cordillera mountains searching for f _____ _____ _____ _____ _____, which are remains of ancient life that have turned to stone. All of a sudden, the ground shook beneath him. Jay ran over a hill and saw that there had been a huge landslide. He went over to look at the piles of rocks and saw layers of s _____ _____ s _____ _____ _____ _____, a type of sedimentary rock. Fossils are found in sandstone, so Jay was excited to search through the rocks! Just as he began to dig, he found fossilized bones. The bones had turned to stone through a process called _____ _____ s s _____ _____ _____ _____ _____ _____ _____ _____. Jay saw that the fossils belonged to an Apatosaurus. These bones are examples of b _____ _____ _____ _____ _____ _____ i l _____, which are fossilized parts of plants and animals. Jay hiked further up the mountain and found fossilized dinosaur dung, called c _____ _____ _____ _____ _____ _____ _____ _____. He also found a huge footprint, which is an example of a t _____ _____ _____ f _____ _____ _____ _____ _____. Jay carefully removed the fossils from the rocks and donated them to a museum.

Activity 2: Find Me

Directions. Encircle the 8 words listed below. Words may appear straight across, back-word straight across, up, and down.

COPROLITE    PALEONTOLOGIST FOSSILS    MINERALIZATION SEDIMENTARY    SANDSTONE FOSSILIZATION    POROUS

L	N	O	I	T	A	Z	I	L	A	R	E	N	I	M
S	T	S	I	G	O	L	O	T	N	O	E	L	A	P
E	K	B	K	S	D	Z	U	I	L	I	H	K	M	F
D	C	L	T	J	Q	L	W	O	G	B	M	I	N	O
I	Y	E	I	N	M	P	Q	R	K	J	P	A	T	S
M	F	P	D	L	S	A	N	D	S	T	O	N	E	S
E	R	O	I	M	I	X	Y	U	E	R	J	P	J	I
N	D	K	S	Z	R	F	Z	T	J	A	X	T	Q	L
T	E	B	P	S	M	E	I	L	W	B	P	I	Y	I
A	Q	V	Y	E	I	L	X	V	Y	O	F	Q	V	Z
R	Z	I	K	F	O	L	P	M	R	A	M	R	G	A
Y	C	V	W	R	H	R	Y	O	K	V	F	I	L	T
M	L	S	P	Q	U	N	U	P	I	P	W	E	H	I
T	V	O	F	M	B	S	A	R	T	F	N	F	B	O
N	C	G	Z	U	R	N	L	O	N	I	H	O	A	N

Activity 3: Let’s Trace

Look and analyze at the illustration below and answer the question listed below.

[chart: geologic time scale; GEOLOGIC TIME SCALE, 650 MILLION YEARS AGO TO THE PRESENT]

Axis label: Million of years ago. Printed axis ticks: 0, 1.8, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650. Values are not labeled on the chart for individual rows.

Era	Period	Events
Cenozoic	Quaternary	evolution of humans
Cenozoic	Tertiary	mammals diversify
Mesozoic	Cretaceous	extinction of dinosaurs; first primates; first flowering plants
Mesozoic	Jurassic	first birds; dinosaurs diversify
Mesozoic	Triassic	first mammals; first dinosaurs
Palezoic	Permian	major extinctions; reptiles diversify
Palezoic	Carboniferous: Pennsylvanian	first reptiles; scake trees; seed ferns [transcriber’s note: this events cell spans the Pennsylvanian and Mississippian rows]
Palezoic	Carboniferous: Mississippian
Palezoic	Devonian	first amphibians; jawed fishes diversify
Palezoic	Silurian	first vascular land plants
Palezoic	Ordovician	sudden diversification of metazoan families
Palezoic	Cambrian	first fishes; first chordates
Late Proterozoic		first skeletal elements; first soft-bodied metazoans; first animal traces

1. For how long has there been life on Earth?

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2. For what percentage of time has life existed on Earth (round to the nearest whole number)?

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3. For about how many years of geological time have humans existed on Earth?

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4. For about how many years of geological time have the dinosaurs existed on Earth?

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5. Did dinosaurs exist at the same time as humans?

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6. How do scientists determine when an era begins and when it ends?

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7. What is the purpose of making a geological timeline?

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Notes to the Teacher

This module will help you understand the concepts about animal reproduction. All parts are comprised of activities. Be guided with the instructions on how you will answer each. Expectedly, you will meet the target at the end of the module.

What’s New

The Story of Fossils by Patti Hutchison

Imagine you are hiking in the woods. As you walk up a steep hill, you find a fossil. It is a mold of many tiny seashells. What would seashells be doing in the middle of the woods?

Most fossils are found in sedimentary rocks. These rocks form on the surface of the earth. They record the processes that have happened on the surface, including life. Scientists are able to arrange fossils according to age. This is called the fossil record. By studying the fossil record, scientists have found that the earth and its life forms have gone through many changes in the past.

Fossils have taught us how and when rock layers have formed. They have also helped scientists learn about life forms that have come and gone. Fossils have even taught us about the climate of the earth long ago.

The Geologic Time Scale is divided into huge blocks of time called eras. Eras are defined by major changes in the fossils found in the sedimentary rock layers that were formed during those time spans.

Activity 4

Directions: Read the story entitled “The Story of Fossil” by Patti Hutchison. Answer the guide questions stated below.

1. In what type of rocks are FOSSILS made of?

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2. How do scientists arrange discovered fossils?

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3. How did fossils help and teach scientist about the history of the earth?

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4. Aside from geological aspect, what other aspects can be predicted by guide fossils? How? (climatic, organismic etc.)

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What is It

Activity 5

Read and analyze the statements below. Write T if the statement is TRUE and F if the statement is FALSE.

_______ 1. Scientists determine when an era begins and when it ends through geological timeline.

_______ 2. Dinosaurs exist at the same time as humans.

_______ 3. The purpose of making a geological timeline is to identify age of organism through its fossils.

________ 4. Quaternary period of geological time has humans evolved on Earth.

_______ 5. Triassic Period of geological time have the dinosaurs existed on Earth.

What’s More

Activity 6

Directions: Write the division and period of the listed organism below. Refer to geological time scale.

Organism	Era	Period
1. first vascular land plants	____________	____________
2. jawed fish diversity	____________	____________
3. evolution of humans	____________	____________
4. first chordates	____________	____________
5. mammals diversify	____________	____________
6. first primates	____________	____________
7. dinosaurs’ diversity	____________	____________
8. major extinctions of reptiles’ diversity	____________	____________
9. sudden diversification of metazoan families	____________	____________
10. first flowering plants	____________	____________

Activity 7: Crossword Puzzle

Directions. Complete the crossword by filling in the word that describes each clue.

[illustration: blank crossword grid with clue numbers 1 to 8 printed in some of the cells]

Across:

2. a term used with two symmetrical shells – mirror images of each other.
3. the term “crinoid” means
4. type of proteins that make up the skin, hair and nails.
5. multicellular organisms in the sea that often live in colonies and served as habitat of marine organisms

Down:

1. exoskeletons are made up of this material
2. common slow-moving gastropod lived inside their shells
3. phylum where starfish and sea urchins belong
4. individuality of coral is called _____.

What I Have Learned

Fill in the blanks. Read and analyze the statements below. Write the word that will complete the sentence/paragraph.

1. _____________________ are the remains or evidence of prehistoric plants and animals that have fossilized.
2. Fossils were used as markers when building up the geologic time scale. The names of most of the eons and eras end in “zoic” because these time periods were recognized by the _____________________ present at the time.
3. The geologic time scale is the “calendar” for events in Earth’s history. It subdivides all time since the end of the Earth’s formative period as a planet (nearly 4 billion years ago) into named units of abstract time: in descending order of duration, which are _________, __________, _________ and ___________.
4. The _____________________ provides a system of chronologic measurement relating stratigraphy to time that is used by geologists, paleontologists and other Earth scientists to describe the timing and relationships between events that have occurred during the history of the Earth.
5. The Geologic Time Scale is divided into huge blocks of time called eras. Eras are defined by major changes in the fossils found in the _____________________ rock layers that were formed during those time spans.

What I Can Do

Activity 7

There are tables of fossils presented below. In the first box, choose an example and draw its physical structure. Second box and third box are references that serve as your guide to choose what organism you prefer to draw. Check the example. Good luck!

Example:

[illustration: branching tabulate coral fossil]	Branching Tabulate Coral Age: Devonian (approximately 416 to 359 million years ago) Class: Anthozoa Modern Relatives: Corals still exists today.	Branching Tabulate Coral is a marine animal. Corals are multicellular organisms that often live in colonies. The individual animal is called a polyp. There are many different species of coral, with different forms, shapes, and sizes.

1.	TRILOBITE Age: Devonian (approximately 416 to 359 million year ago) Phylum: Arthropod Modern Relatives: Crabs, Spiders and insects	Trilobites were marine arthropods. The first trilobites show up in the fossil record dating back to about 525 million years ago. There were many different types of trilobites, ranging in size from 1mm to 72mm (28 inches long!) Trilobite species went extinct by 250 million years ago. Trilobite fossils are formed from the exoskeletons. These were made of chitin, like some insects and others organisms like lobsters. They split apart and shed their shell as they grow, just like lobsters do.

2.	Crinoid Age: Devonian (approximately 416 to 359 million years ago) Phylum: Echinoderm Modern Relatives: Starfish, sea urchins and sea cucumbers	Crinoids were marine animals. Its name means “Lily”. It is in the same phylum (Echinoderm) as starfish and sea urchins. Crinoids ate by filtering food out of the water with it arms. Its mouth and anus were next to each other in the calyx. It “rooted” in place with a holdfast. When crinoids die, their stems quickly break apart. The most common fossils of crinoids are the stem which is sometimes broken into little “cheerio” like pieces.

3.	Gastropod Age: Cretaceous (Approximately 146 to 65 million years ago) Phylum: Mollusk Modern Relatives: Snails, Slugs and Whelks	Gastropods were marine animals. There were many different species of gastropods. All had coiled shells, but some were tightly coiled while some were loosely coiled. They had many different shapes and surface texture. The animals lived inside their shells, taking up the whole inside of the long shell. They could retract into their shells, covering the opening with their foot.

4.	Fossil Clam Age: Cretaceous (approximately 146 to 65 million years ago) Class: Bivalve Modern Relatives: Oysters, Scallops and Mussels	Fossil clams are marine animals. Clams are bivalves, with two symmetrical shells – the shells are mirror images of each other. Fossil clams range in size from a few millimeters to up to 2 meters (about 6 feet) in diameter. Clams lived inside their shells and had a muscular foot they used to borrow and move around. They lived in colonies on the ocean floor. Some clams had smooth shells while some were rough.

Assessment

Multiple Choice. Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper.

1. Why do most of the eons and eras end in “zoic”?

• A. because these time periods were recognized by the animal life present at that time
• B. because these time periods were recognized by the plants present at that time
• C. A and B
• D. none of the above

2. Which of the following marine animals are bivalves with two symmetrical shells – the shells are mirror images of each other?

• A. crinoids
• B. fossil clam
• C. gastropods
• D. trilobites

3. How were the scientists able to arrange the fossils they gathered?

• A. They were able to arrange the fossils according to age.
• B. They were able to arrange the fossils according to structure.
• C. They were able to arrange the fossils according to chemical content.
• D. They were able to arrange the fossils according to place of discovery.

4. What do you call the marine arthropods that were made of chitin, like some insects and other organisms like lobsters?

• A. crinoids
• B. fossil clam
• C. gastropods
• D. trilobites

5. What do you call the process by which the remains of ancient living things are turned into rock?

• A. fertilization
• B. fossilization
• C. fragmentation
• D. metamorphosis

6. In what phylum do crinoids belong?

• A. arthropods
• B. echinoderms
• C. gastropods
• D. mollusks

7. What do you call the person who studies fossils and ancient life?

• A. anthropologist
• B. archeologist
• C. biologist
• D. paleontologist

8. Which of the following marine animals lived inside their shells, taking up the whole inside of the long shell?

• A. echinoderms
• B. gastropods
• C. mollusks
• D. sea arthropods

9. In what type of rocks are fossils made of?

• A. igneous rock
• B. metamorphic rock
• C. sedimentary rock
• D. all of the above

10.In Paleozoic Era, in what period did the first vascular land planet exist?

• A. Cambrian
• B. Devonian
• C. Ordovician
• D. Silurian

11.In what period the first mammals and dinosaurs existed?

• A. Cretaceous
• B. Jurassic
• C. Permian
• D. Triassic

12.What do you call the remains or evidence used as markers when building up the geologic time scale?

• A. fossil
• B. minerals
• C. piles of rock
• D. sandstone

13.In what era did the first skeletal elements, soft-bodies metazoans, and animal traces exist?

• A. Cenozoic Era

  
  

• B. Late Proterozoic

  
  

• C. Mesozoic Era

  
  

• D. Paleozoic Era

  
  

14.Which of the following does NOT belong to Paleozoic Era?

• A. Cambrian
• B. Devonian
• C. Jurassic
• D. Silurian

15.In what era did the rocks with fossils of animals and plants such as dinosaurs, mammals and trees form?

• A. Cenozoic Era
• B. Mesozoic Era
• C. Paleozoic Era
• D. Phanerozoic Era

Additional Activities

Do you think that the average annual global temperature and carbon dioxide levels have been consistent throughout the history of earth? Justify your answer.

Answer Key

[transcriber’s note: this page is printed rotated 180 degrees; the sections are transcribed in their upright reading order]

Assessment

• A 1.
• B 2.
• A 3.
• D 4.
• B 5.
• B 6.
• D 7.
• B 8.
• C 9.
• D 10.
• D 11.
• A 12.
• B 13.
• C 14.
• D 15.

What I Know

• C 1.
• A 2.
• B 3.
• C 4.
• D 5.
• B 6.
• A 7.
• D 8.
• B 9.
• D 10.
• D 11.
• B 12.
• A 13.
• D 14.
• B 15.

What’s in

Activity 1

• Paleontologist
• Fossils
• Sandstone
• Fossilization
• Body fossils
• Coprolite
• Trace fossil

Activity 2

1. Answer may vary according to student’s perception

What’s New

[transcriber’s note: in the printed key, the “What’s New” label and the Activity 4 entry sit in the same box as the Activity 3 entry, and the order of these three entries is taken from the upright layout]

Activity 3

Answer may vary according to student’s perception

Activity 4

Answer may vary according to student’s perception

What’s It

Activity 5

• T 1.
• F 2.
• T 3.
• T 4.
• F 5.

What’s More

Activity 6

• Silurian – Paleozoic 1.
• Devonian – Paleozoic 2.
• Quaternary – Cenozoic 3.
• Cambrian – Paleozoic 4.
• Tertiary – Cenozoic 5.
• Cretaceous – Mesozoic 6.
• Jurassic – Mesozoic 7.
• Permian – Paleozoic 8.
• Ordovician – Paleozoic 9.
• Cretaceous – Mesozoic 10.

Activity 7

Across 2. Bivalves 3. Lily 5. Keratin 7. Coral

Down

1. Chitin
2. Snails
3. Echinoderm
4. Polyp

References

Chambers, John E. (July 2004). “Planetary accretion in the inner Solar System” (PDF). Earth and Planetary Science Letters. 223 (3–4): 241–252. Bibcode:2004E&PSL.223..241C. doi:10.1016/j.epsl.2004.04.031.

Deconto, Robert M.; Pollard, David (2003). “Rapid Cenozoic glaciation of Antarctica induced by declining atmospheric CO2”. Nature. 421 (6920): 245–249. Bibcode:2003Natur.421..245D. doi:10.1038/nature01290. PMID 12529638.

Ogg, J.G.; Ogg, G.; Gradstein, F.M. (2016). A Concise Geologic Time Scale: 2016. Elsevier. p. 20. ISBN 978-0-444-63771-0. Ogg (eds.). The geologic time scale 2012 (1st ed.). Amsterdam: Elsevier. pp. 359–365. doi:10.1016/B978-0-444-59425-9.00016-0. ISBN 978-0-44-459425-9.

Claire; Macchiarelli, Roberto; et al. (2014). “The 2.1 Ga Old Francevillian Biota: Biogenicity, Taphonomy and Biodiversity”. PLoS ONE. 9 (6): e99438. Bibcode:2014PLoSO…999438E. doi:10.1371/journal.pone.0099438. PMC 4070892. PMID 24963687

Van Kranendonk, Martin J. (2012). “16: A Chronostratigraphic Division of the Precambrian: Possibilities and Challenges“. In Felix M. Gradstein; James G. Ogg; Mark D. Schmitz; abi M.

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Ground Floor, Bonifacio Bldg., DepEd Complex Meralco Avenue, Pasig City, Philippines 1600

Telefax: (632) 8634-1072; 8634-1054; 8631-4985

Email Address: blr.lrqad@deped.gov.ph * blr.lrpd@deped.gov.ph