Usos de Suelo

and similar to the solutions achieved in a related problem.

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Problem-Solving Teachers instructional guide (PSTIG)

Week: 3

Topic: Supporting Tissues and Systems in Animal Sub Topic: Forms of Skeleton: Chilin, Cartilage, and Bone

Types of skeleton:

Vertebrate skeleton Mammalian skeleton Joints

Functions of skeleton in Animal

Instruction Objectives: At the end of the lesson student should be able to:

a) Define skeleton

b) Mention forms of skeletal materials and examples of animal that possesses each of them

c) Mention and describe types of skeleton d) Describe mammalian skeleton

e) Describe vertebral column f) Describe a typical vertebral

g) Identify different types of vertebral column

h) Mention characteristics features of each type of vertebral column i) Identify and describe ribs and sternum

j) Describe appendicular skeleton (pectoral and pelvic girdles) k) Identify pelvic girdle and pectoral girdle

l) Draw each bone of vertebral column and appendicular bone PRESENTATION

Lesson One: 80 minutes

STEP ONE: The teacher introduces the lesson by asking the students to mention bone in their body and show the bone mentioned. What is the use of the bone in the body? After the students‟ response, the teacher defines skeleton as the bony framework of the body which provides support, shape and protection to the soft tissues and organs in the body.

STEP TWO: the teacher mentions and discusses three types of skeletal materials in animals. These are; chitin, cartilage and bone

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1) Chitin: this is tough, light and flexible materials. Chitn is a major component of arthropods. It is freely permeable to water and strengthened by the deposits of hardened proteins and minerals. It found in insects, prawn, centipede e.t.c.

2) Cartilage: this is a tissue found in the skeleton of complex vertebrates. It consists of living cells (chondroblasts), carbohydrate and protein fibres. It is tough and flexible. It helps in cushion the effects of bone moving against bone when we move. There are three types of cartilage viz; hyaline cartilage, found in trachea and bronchi. Fibro cartilage; found in the disc between the small bone of vertebral column. And elastic cartilage found in the pinnea (external ear) of mammals

3) Bone: this is also a tissue and is the major component of vertebrate skeleton.bone consists of living cells osteocytes, protein fibres collagen and non-living minerals calcium carbonate and calcium phosphate. Bone has blood supply to nourish them.

STEP THREE: the teacher mentions and describes three types of bone. They are hydrostatic skeleton, exoskeleton and endoskeleton.

1) Hydrostatic skeleton: animal with this type of skeleton use fluid pressure to provide support. The fluid is secreted to fill the spaces in the body. This fluid presses against the muscular body wall to contract, exert a force against the fluid. Hydrostatic skeleton is found in Earthworm.

2) Exoskeleton: this is an outer skeleton found outside the body of arthropods.

The main component of this skeleton is chitin. It is found in crustaceans, insects, myriapods.

3) Endoskeleton: this is the internal skeleton found in major vertebrates.

Endoskeleton of vertebrates is composed of bones. The bone can grow steadily as the animal grows. Bone of many shapes and sizes make up the endoskeleton.

STEP FOUR: the teacher discusses the general plan of mammalian skeleton, which consists of two groups; the axial skeleton and the appendicular skeleton.

Axial skeleton is made up of the skull, the vertebral column, ribs and sternum.

Appendicular skeleton consists of the girdles- pectoral girdle and pelvic girdle. The skull is up made of several flat bones which are joined to form the brain box, the face and lower jaw. The vertebral column known as backbone is the central supporting structure. It consists of 33 vertebrae. The vertebrae are separated by fibro-cartilage but held together by ligament. There are five types of vertebrae in the vertebral

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column; the cervical vertebra, the thoracic vertebra, the lumbar vertebra, the sacrum vertebra and the caudal vertebra.

Lesson Two: 80 Minutes

The teacher starts introducing the new teaching strategy of problem-solving by altering the conventional sitting arrangement as he/she divides the class into groups of five to six students per group. The purpose of grouping is that the apparatus may not be able to go round students individually, and this allows members of each group to ignite intellectual interactive spirit among one another.

Students main activities in the first lesson is to listen to teacher‟s explanation on the topic of the day which is theoretical background.

Step 1: the teacher introduces the lesson with a class activity presented to the students thus;

Specimen A, B and Care bones obtained from mammalian skeleton

Identify each specimen and categorise them in to the group they belong to.

a) Where can you find each of the specimen in mammalian body.

b) State the differences among them.

Students take the specimens and answer questions raised.

Step 2: The teacher lead discussion on the answers provided by the students. Asks students to explain how they arrived at the answers. Students explain how they got the answer, e.g the source of information for solution.

Step 3: The teacher introduces students to the steps involved in problem solving as