PREVISIOnES VInCuLADAS A LAS PERSOnAS VíCTImAS DuRAnTE LAS DISTInTAS ETAPAS DEL PROCESO
9.6 Participación de grupos especiales de víctimas
Evolutionary Relationships: Taxo Taxonomy nomy
Content Standard Content Standard
The learners demonstrate an understanding of Basic Taxonomic Concepts and Principles, Description, Nomenclature, Identification and Classification.
Performance Standard Performance Standard The learners shall be able to:
• construct a dichotomous key Learning Competency Learning Competency
The learners should be able to identify the unique/distinctive characteristics of a specific taxon relative to other taxa STEM_BIO11/12IIIh-j-15STEM_BIO11/12IIIh-j-15
Specific Learning Outcomes Specific Learning Outcomes
At the end of the lesson, the learners will be able to:
• describe the Linnaean system of classification;
• classify organisms into a hierarchy; and
• construct and use dichotomous keys for identification.
180 MINS 180 MINS
LESSON OUTLINE Introduction
IntroductionCommunicating Learning Objectives 20 Motivation
Motivation Classification Tasks 30
Instruction
Instruction Discussion on Linnaean Classification 60 Practice
Practice Use of dichotomous keys for identification
45
Enrichment
Enrichment Assignment 15
Evaluation
Evaluation Group Work 10
Materials Materials
Writing materials, sheets of paper, photos of plants (citrus fruits) and animals (turtles)
Resources Resources
(1) Pancho JV, William G SM. Vas cular Flora of Mount Mak iling and Vicinity (Luzon: Philippines). Part 2. Laguna, Philippines: National
Academy of Science and Technology (NAST) Philipp ines, Department of Science and Technology, Bicutan, Taguig City and Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños College; 2006. 223-241pp.
(2) Reece JB, Urry LA, Cain ML, Wasserman SA, Minorsky PV, Jackson RB.
Campbell Biology.10th edition. San Francisco, California, USA: Pearson Education Inc.; 2014. 548-549 pp.
(3) Simpson MG. Plant Syst ematics. MA, USA: Else vier Academic Press Publications; 2006. 12-13pp.
Additional Resou
Additional Resources at the Backrces at the Back
INTRODUCTION (20 MINS) Communicating Learning Objectives Communicating Learning Objectives
1. Introduce the following learning objectives using any of the suggested protocols (Verbatim, Own words, Read-aloud)
I. I can describe the Linnaean system of classification.
II. I can classify organisms into hierarchy of groups based on similarities and distinct characters.
III. I can use and construct dichotomous keys.
Review Review
2. Say, “The practice of classification is almost everywhere such that, humans tend to classify almost everything.. For instance, one can describe the clothes to wear, types of utensils used in the kitchen and even the type of footwear . Classification becomes an essential part of everyday life and the habit can be quite useful. In the past humans have classified living organisms based on their general form and economic use. The type of classification may not be that systematic as compared to the ones we used today. However, it does not deny the fact that they were useful.”
Early taxonomists (e.g. Emperor Shen Nung of China around 3000BC) have classified plants based on practical uses—for food, as herbal medicine, for shelter and others.
At this point, ask learners how they will classify objects or items commonly encountered or used in everyday life such as those found in homes, schools and neighborhood/communities.
The following are sample responses:
I. Kitchen utensils (can be classified based on their use--- spoons, forks, ladles, pots, pans) II. Clothing (skirts, blouses, socks, pants)
III. Learners in schools/universities (can be classified based on gender, age group, etc) IV. Books in the Library (can be classified based on Dewey decimal system)
Teacher Tip:
Teacher Tip:
Here are some definitions:
Classification
Classification – method of grouping organisms; arranging entities into some type of order to provide a system for cataloguing and expressing relationships between these entities
Hierarchy
Hierarchy- a system of organizing groups into ranks according to status; putting groups at various levels according to importance or power
Nomenclature
Nomenclature- the formal naming of taxa according to some standardized system. For plants, fungi, and algae, rules for naming are provided by the International Code of Botanical Nomenclature. For animals, rules on naming are based on the International Code of Zoological Nomenclature.
Identification
Identification- is the process of associating an unknown taxon with a known one
Description
Description- is the assignment of features or attributes (characters) to a taxon
Taxonomy
Taxonomy- the theory and practice of classifying organisms
Reminder:
Reminder:
Taxonomy
Taxonomyis a major part of systematics that includes description, identification, nomenclature and classification
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3. Ask the learners to define the following biological terms in their own words.
I. classification II. description III. hierarchy IV. identification V. nomenclature VI. taxonomy
4. Say, “ About three hundred years ago, a Swedish botanist and doctor named Carl Linnaeus realized:
‘All the real knowledge we have depends on the method by which we distinguish the similar from the dissimilar. The greater the number of natural distinctions we make, the clearer becomes our idea of things…from here Linnaeus set himself the task of devising a method to : “join the similar to the similar, and to separate the dissimilar from the dissimilar in nature” Note that the Linnaeus method was known as Linnaeus’ system of classification or the Linnaean taxonomy.
5. Stress the importance of a classification system, nomenclature and identification 6. Topics to be covered:
I. Some Early Taxonomists II. Linnaean System of Classification III. Binomial Nomenclature
IV. Classifying organisms based on similar and distinct characters V. The dichotomous key
MOTIVATION (30 MINS)
Classification Tasks
1. Tell learners to form a group, with 4 members.
2. Ask them to look inside their bags and gather all possible types of writing and coloring materials they can obtain within their group (e.g. ballpen, sign pen, whiteboard marker, pencil, highlighter, color pens ). Ask learners to classify these materials.
3. Ask learners to write down key features to be used for groupings. Place these features in a table (learners may focus on characters based on absence (-) or presence (+).
Sample Table:
Sample Table:
4. Ask learners to create their own simple hierarchical system of classification by assigning ranks to groups created. They may create a label for the ranks. A flow chart may be constructed.
F
Feeaattuurrees s bbaalll l ppeen n oorrddiinnaarry y ppeenncciil l hhiigghhlliigghhtteerr whiteboardwhiteboard marker marker short (less than 6
inches) - - - - + +
--long (more than 6
inches) + + + + - - ++
with black ink + + - - - - ++
without ink - + - + - -
--120
Sample Flow Chart:
Sample Flow Chart:
5. Ask for a volunteer to present the chart. (This activity will give them the actual feeling of how classification is done.)
INSTRUCTION (60 MINS) Setting the Atmosphere and Discussion Setting the Atmosphere and Discussion
1. After getting a feel of how classification is done, learners begin to appreciate the job of early taxonomists. Discuss a little about the history of classification and the scientists who have contributed to the field of taxonomy.
2. The taxonomic system was devised byCarolus LinnaeusCarolus Linnaeus (1707-1778). It is a hierarchical system since organisms are grouped into ever more inclusive categories from species up to kingdom.In 1981, a category higher than a kingdom, called domain, was proposed by Carl Woese. The table below illustrates how four species are classified using the present classification system. (Note that it is standard practice toitalicize the genus and species names).
Teacher Tip:
Teacher Tip:
Discuss on some scientists’ contribution to the classification system throughout history.
For instance, Andrea Cesalpino, John Ray, Augustus Quirinus Rivinus, Joseph Pitton de Tournefort, Robert Whittaker, and Carl Woese. ( Ask learners to make a personal research on their respective contributions.)
D
DOOMMAAIIN N EEUUKKAARRYYAA KINGDOM
KINGDOM Animalia Plantae
PHYLUM
PHYLUM Chordata Arthropoda Magnoliophyta
CLASS
CLASS Mammalia Insecta Lilopsida
ORDER
ORDER Primates Canivora Diptera Liliales
FAMILY
FAMILY Hominidae Canidae Drosophilidae Liliaceae
GENUS
GENUS omo H Canis Drosophila Allium
specific epithet
specific epithet sapiens familiaris melanogaster cepa SPECIES
SPECIES Homo sapiens Canis familiaris Drosophila melanogaster
Allium capa
COMMON NAME
COMMON NAME human dog fruit fly onion
Teacher Tip:
The word ‘species ’ is both in singular and plural form; there is no such word as
‘specie’
*Classification is based on key characters/
features used in groupings.. Take for example the classification of humans. Refer to the table below.
Note:
Most of us are accustomed to the Linnaean system of classification that assigns every organism a kingdom, phylum, class, order, family, genus, and species
The Linnean method is artificial since organisms are classified based on morphological similarities and not on evolutionary relationships.
Phylogenetic classification is based on evolutionary history or pattern of d escent.
D
DOOMMAAIIN N EEUUKKAARRYYA A FFEEAATTUURREESS
KINGDOM Animalia Organisms that are able to move on their own PHYLUM Chordata Animals with a backbone
CLASS Mammalia Chordates with fur or hair and milk glands ORDER Primates Mammals with grasping fingers
FAMILY Hominidae Primates with relatively flat faces and three-dimensional vision GENUS Homo Hominids with upright position and large brain
specific epithet sapiens Members if the genus Homo with a high forehead and notably thin skull bones
SPECIES Homo sapiens COMMON NAME human
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3. The Linnaean taxonomy which is hierarchical in nature is the most employed system nowadays.
Note: This system was created long before scientists understood that organisms evolved.
4. Working as teams (4 learners per team) ask learners to come up with their own mnemonic. They may share it with other groups (Which mnemonic works best for you?).
5. Discuss binomial nomenclature.
Nomenclature refers to the practice of assigning scientific names. Binomial comes from the words
“bi” meaning “two” and “nomen” meaning “name”. A species name consists of two parts: the genus or generic name and the specific epithet. The first letter of the genus is always capitalized (e.g. Canis) while the specific epithet is not capitalized (e.g. familiaris). One can distinguish a species name from the way it is written. Species name can be in bold lettersoror underlinedoror italicized.
Teacher Tip:
Teacher Tip:
Linnaeus introduced the binomial system of nomenclature for plants, animals, fungi, protozoans and protists. The binomial system consists of the generic name and the specific epithet. Thus, the species name is binomial in nature.
Trivia:
Trivia:
What is the longest species name ?
Parastratiosphecomyia Parastratiosphecomyia stratiosphecomyioides stratiosphecomyioides
This is the scientific name of the soldier fly.
Sample mnemonics:
Sample mnemonics:
• K K ingsPPlayCChess O OnFFineGGlassSSets
• K K ingsPPlayCChessOOnFFinelyGGreen S
Spaces
• K K eepPPondCCleanOOrFFroggyGGetsSSick
• K K ingsPPlayCChessOOnFFineGGrained S
Sand
• K K ingPPhilipCCameOOverFForGGreenSSoup
• K K indlyPPutCCandyOOutFForGGood Learner
Learners
Examples:
Examples:
Discuss dichotomous key as a tool in identification.
A dichotomous keydichotomous key is a tool that helps identify unknown organisms to some taxonomic level (e.g., species, genus, family, etc.). The key is constructed in such a way that a series of choices is made that leads the user to the correct identity of a sample organism. "Dichotomous" means, "divided into two parts." Therefore, a dichotomous key always offer two choices for each step, each of which describes key characteristics of a particular organism or group of organisms.
Sample Key: K
Sample Key: Key to comey to common mon snackssnacks S
SPPEECCIIEESS GGEENNUUSS ENGLISH MEANINGENGLISH MEANING SPECIFIC EPITHETSPECIFIC EPITHETENGLISH MEANINGENGLISH MEANING
Canis familiaris Canis a dog familiaris familiar
Felis catus Felis happy catus cat
Teacher Tip:
Do your personal review on the characteristics of the citrus family before giving this exercise. Be familiar with terms associated with the family.
Explain the rationale of the activity.
The importance of correct identification cannot be underestimated.
Present the plant pictures to learners and give clear instructions on what they need to do.
Note:
You may provide photos.
1a. Plastic bag packaging Go to 2 1b. Hard tube packaging Go to 4 2a. Chips have ridged surface Go to 3
2b. Chips have non-ridged surface Lays Cheese and Onion 3a. Chips orange color Tortillos Cheese
3b. Chips tan color V-Cut
4a. Chips orange color Pringles Cheddar Cheese 4b. Chips have other color Go to 5
5a. Chips solid tan with no speckles Pringles Original
5b. Chips tan with greenish speckles Lays Stax Sour Cream and Onion
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6. Now that you have an idea of how a dichotomous is constructed, let us try making one based on real organisms. Let’s try something quite challenging.
Practical example/ work with actual groupings Practical example/ work with actual groupings
7. Say, ”Many plants in the Philippines are often confused because they share characteristics and look similar….among these are plants belonging to the Citrus family (Family Rutaceae). We are quite familiar with this group but often one identity is interchanged with the other or all examples are treated as the same…”
8. Ask learners to work in groups. Show to class actual fruit samples with few leaves and flowers or if not, colored pictures of these plants belonging to calamansi family (Rutaceae). Generally, family Rutaceae is composed of trees or shrubs that are often spiny and rarely herbal. The leaves can be simple or compound, alternately or oppositely arranged, with few to numerous pellucid glands, and without stipules. In the Philippines, there are 20 genera and 83 species.
9. Using these fruits below from family Rutaceae, tell your learners to observe the features or characteristics of each fruit. Place all these characters in a table. Suggest to them possible characters that they can use like presence/absence of a feature or trait, shape, color etc. Use common names at the end of each choice.
I. citron II. key lime III. pomelo
IV. makrut lime or Mauritius papeda V. calamondin or calamansi VI. bitter orange VII. mandarin orange VIII.Cochin China Atalantia
10. Ask for group volunteers to show their dichotomous key in class. Comment on how they constructed their key. After the group has presented their key, show the correct dichotomous key to your learners.
11. Below is the dichotomous key you will show the learners after they have constructed their own key.
Dichotomous key to t
Dichotomous key to the different fruits he different fruits of family Rutaceaeof family Rutaceae
12. Ask your learners to compare their key with the one you showed them. After comparing, let them answer the questions below:
I. What trait(s) or character(s) did you use to separate the fruits into groups? Give an example to illustrate this.
II. Notice differences among fruits. These differences set them distinct from the others. Can you give an example to show this?
13. Stress that the presence of similarities among organisms will place them in a group. Differences among organisms would set them distinct from each other.
Teacher Tip Teacher Tip Glossary of terms Glossary of terms
1. axillaryaxillary –relating to or located in an axil: an axillary bud
2. basalbasal- located at or near the base of a plant stem, or at the base of any other plant part
3. berryberry –fleshy fruit with many seeds derived from a single flower containing one ovary
4. foliagefoliage- collectively, a cluster of leaves 5. fascicledfascicled- in bundles or clusters; can
be appied to stems, flowers or leaves 6. globoseglobose-rounded
7. petiolepetiole--the stalk that attaches the leaf blade to the stem;
8. racemeraceme- an inflorescence in which the pedicellate flowers are borne along the main stem, with the oldest flowers at the base
9. solitarysolitary-growing singly 1a. Foliage not constricted; berries less than 2 cm in diameter Cochin China Atalantia
1b. Foliage constricted; berries exceeding 2 cm in diameter Citrus 2a. Leaves not constricted; petioles not or narrowly winged; fruits
ellipsoid
Citron
2b. Leaves constricted, petioles winged; fruits globose Go to 3
3a. Flowers in axillary racemes Go to 4
3b. Flowers solitary or fascicled in leaf axils Go to 5 4a. Basal leaf portion narrowly winged; fruits small key lime 4b. Basal leaf portion broadly winged; fruits very large pomelo
5a. Basal leaf portion broadly winged makrut lime
5b. Basal leaf portion narrowly winged Go to 6
6a. Fruits 2-3 cm in diameter Calamansi
6b. Fruits much larger Go to 7
7a. Fruits tight-skinned bitter orange
7b. Fruits loose-skinned mandarin orange
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PRACTICE (45 MINS) Learners will still work as a group.
1. Present to each group photos of 4 unknown turtles. Assign a letter or number for each photo.
Provide a dichotomous key for each group.
2. Say, “The world has six species of marine turtles with the green sea turtle having two subspecies.
The loggerhead, flatback, hawksbill, leatherback and green sea turtle are considered endangered.
The olive Ridley is plentiful in some seas. The Philippines is a rich haven for these marine creatures owing that we are part of the Coral Triangle. Now NAME that TURTLE to save it!”
3. Ask learners to use the provided dichotomous key to determine the identity of the unknown turtles.
Check if the group got each species correct. Rank each group based on who accomplished the task first. Then, ask each group the difficulties they encountered and how they overcame these difficulties.
KEY TO COMMON SPECIES OF TURTLES KEY TO COMMON SPECIES OF TURTLES
1a.Has scutes arranged in a distinct patterns forming medial, lateral,
and marginal positions on the carapace Go to 2
1b.Has no scutes on the carapace but has longitudinal ridges on the carapace
Leatherback turtle
2a. Medial scutes 5 Go to 3
2b. Medial scutes more than 5 Olive Ridley turtle
3a. Lateral scutes 4 Go to 4
3b. Lateral scutes more than four Go to 5
4a. Medial scutes imbricated and the beak is ‘hooked’ Hawksbill turtle 4b. Medial scutes are not imbricated and the beak is not noticeably
hooked
Go to 6
5a. With terminal scute at the centerline along the posterior margin of the plastron
1. axillaryaxillary –relating to or located in an axil: an axillary bud
2. basalbasal- located at or near the base of a plant stem, or at the base of any other plant part
3. berryberry –fleshy fruit with many seeds derived from a single flower containing one ovary
4. foliagefoliage- collectively, a cluster of leaves 5. fascicledfascicled- in bundles or clusters; can
be appied to stems, flowers or leaves 6. globoseglobose-rounded
7. petiolepetiole--the stalk that attaches the leaf blade to the stem;
8. racemeraceme- an inflorescence in which the pedicellate flowers are borne along the main stem, with the oldest flowers at the base
9. solitarysolitary-growing singly
Take note of the assigned letter for each picture.
ENRICHMENT (15 MINS)
1. Ask the learners to submit an assignment on other practical uses of biological classification..
EVALUATION (10 MINS) Group Work
2. Divide the class into groups. Learners will still work as a group composed of four (4) members. Ask learners to make their own dichotomous key in order to identify their favorite plants/ vegetables found in a school garden or for instance, in the market. Give them time to think and write down the plants or in their own spare time they can also visit an actual garden. Ask learners to submit their work the following meeting. Ask for difficulties they encountered and strategies they used to make the task easy.
5b. Without terminal scute at the centerline along the posterior margin of the plastron
Loggerhead turtle
6a. Posterior margin of the carapace pointed Black Turtle 6b. Posterior margin of the carapace rounded Go to 7 7a. Lateral scutes of the carapace are noticeably larger than the
medial scutes
Flatback turtle
7b. Lateral scutes of the carapace are nearly the same size as the medial scutes
Green turtle
A
A Black Turtle EE Kemp’s Ridley Turtle
B
B Flatback Turtle FF Leatherback Turtle
C
C Green Turtle GG Loggerhead Turtle
D
D Hawksbill Turtle HH Olive Ridley Turtle
Teacher Tip
Practice more on using dichotomous keys Practice makes Perfect!
Note:
Note:
Write down the following in the board.
Dermochelys coriacea (Leatherback turtle) Lepidochelys olivacea (Olive Ridley turtle) Eretmochelys imbricata (Hawksbill turtle) Lepidochelys kempii ( Kemp’s Ridley turtle) Caretta caretta (Loggerhead turtle) Chelonia mydas agassizii (Black Turtle)-subspecies of the Eastern Pacific g reen turtle
Chelonia mydas mydas (Green turtle)
Chelonia mydas mydas (Green turtle)