Activity and Summary - Organ and Organ Systems in Animals

Activity 1

Examine a quill feather. Hold the base of the central shaft with one hand and gently bend the tip of the feather with your other hand. Be careful not to break the feather. Next, hold the shaft and wave the feather in the air. Record your observations concerning the structure of the quill feather. Re-late your observations to the feather’s possible function. Describe the function of the feather under “Function of feather” in your data table.

 Examine the vane of the feather. Does the vane appear to be a solid structure? Include a descrip-tion of the quill feather’s vane structure under “Structure of feather” in your data table.

Make a drawing of the quill feather. Label the shaft, vanes and barbs. Compare your diagram with the feather.

Activity 2

Students are divided into groups of three or four and given an earthworm on a damp  paper towel. The paper towel should be placed in container so that the worms do  not move away. For two minutes, students should observe the worm and record its behavior and morphology. Identify the earthworm’s anterior, posterior ends and its external apertures and locate the earthworm’s clitellum. Using a battery torch, focus light on the earthworm and observe whether the earthworm moves towards light or away from light. Why? This will be recorded on their lab sheet under “Worm’s behaviour and morphology.” Students can then watch a short video of an earthworm dissection where the different organs of the worm are labelled and explained. Ask the students to label the different parts of the worm and its anatomy after watching the video. At the end of the lab work, students may be asked to recall about the parts of the worm’s body responsible for regulating, signalling, and performing its behaviour.

Earthworm dissection video

http://www.youtube.com/watch?v=A2BY0hRUA9E

In the given diagram using the terms given below, label the parts of the worm:

Mouth, Anus, Brain, Crop, Gizzard, Intestine, Pharynx, Segments, Clitellum,  Blood vessels, Hearts, Oesophagus, and Nerve Cord.

SUMMARY

Earthworm, Cockroach and Frog show characteristic features in body organization. Lampito mauritii (earthworm) is commonly found in Tamil Nadu, its body is covered by cuticle. It has a long and cylindrical narrow body which is bilaterally symmetrical. All segments of its body are alike except the 14 to 17 segments, which are thick and dark and glandular, forming the clitellum. This helps in the formation of cocoons. A ring of S-shaped chitinous setae is found in each segment. These setae help in locomotion. Earthworm's development is direct and no larva is formed during development.

Cockroach is a typical cosmopolitan insect and exhibits all the fundamental characteristics of class Insecta. The body of the cockroach is compressed dor-so-ventrally, bilaterally symmetrical, seg-mented and divisible into three distinct regions – head, thorax and Abdomen. The photoreceptor organ of the cockroach consists of a pair of compound eyes with mosaic vision. Segments bear jointed ap-pendages. There are three throacic seg-ments of each bearing a pair of walking legs. Two pairs of wings are present, one pair each on 2^nd and 3^rd segment. There are ten segments in abdomen. Fertilization is internal. The development of cockroach is gradual through nymphal stages (pau-rometabolus).

Frogs are cold blooded vertebrates – Poikilotherms. Skin is smooth and moist, Red blood corpuscles are nucleated. Eggs are laid in water. The larvae pass through an aquatic stage before metamorphosing into adult.

Birds are warm blooded, bipedal ver-tebrates. They have an exoskeleton of feathers. Their forelimbs are modified into wings to aid in aerial mode of life.