Introduction
In this experiment, we will study the homology and analogy of animals and plants with the help of their model.
Basic Building Concept
1. Those organs of different plants and animals which are similar in shape but perform different functions are called homologous organs. For example – The spines of barberry and tendril of pea plants have similarly modified leaves. But due to the adaption, both perform different functions.
2. Those organs which perform similar functions but have different structures in different organisms are called analogous organs. For example – tendril of pea and tendril of cucurbit. The first one is a modified leaf and the second one is a modified stem, but both of them perform the similar function of climbing support.
Aim
To study the homologous and analogous properties of plants and animals with the help of their charts/models.
Requirements
1. Plant specimens such as Bougainvillea, cucurbits, potato, and sweet potato,
2. Animal models like bird, butterfly, forelimb of a frog.
Theory
Homologous organs are those organs that have a similar structure and embryonic origin but perform different functions.
Analogous organs are those organs that perform similar functions but same different basic structures.
Procedure
Step 1: Take the model and observe it carefully.
Step 2: Note down all their structures and functions.
Step 3: Draw the well-labelled diagram in your notebook.
| TENDRILS OF CUCURBITS AND SPINES OF BOUGAINVILLEA | FORELIMB OF BIRD AND FORELIMB OF FROG | POTATO AND SWEET POTATO | WINGS OF BUTTERFLY AND WINGS OF BIRD |
|---|---|---|---|
 1. Tendrils of cucurbit are modified stems that are helpful in climbing for support. 2. Spines of bougainvillea are modified stem, helpul in protection. 3. Both of them are homologous organs as they are the same in structure but perform different functions |  1. Upper arm, forearm, wrist, palm, and five fingers are present at the forelimbs of the frog. The humerus is present in the upper arm, radius and ulna in the forearm, carpel in the wrist, metacarpals in the palm, and phalanges in fingers. The forelimb of frogs helps them in absorbing the shock associated with leaping. 2. Upper arms of forelimbs in birds have a humerus, radius, and ulna in forearms, carpel in the wrist, five fingers with phalanges, and palm with metacarpals. The forelimbs help birds in flying. 3. They are homologous organs. |  1. Potatoes have eyes-like structures called nodes. 2. They are modified stems, adopted for storing food. 3. Sweet potatoes are modified roots, adopted in storing foods. 4. They are analogous organs as both of them have different structures but perform similar functions. |  1. The wings of a butterfly are supported by a few muscles, which help in flying in the air. 2. The wings of birds are covered with flesh, skin, and feathers, which help in flying. 3. They are analogous organs as they are structurally different and perform similar functions. |
Result
1. Tendrils of cucurbits and spines of bougainvillea are homologous organs.
2. Forelimbs of birds and forelimbs of frogs are homologous organs.
3. Potato and sweet potato have analogous organs.
4. Butterfly wings and birdwings are analogous organs.
Precautions
1. Observe the specimen carefully.
2. Specimen should be fresh and clean.
Viva Questions and Answers
Q.1 What was the aim of our experiment?
ANS. To study the homology and analogy of animals and plants with the help of their model.
Q.2 What do you understand about homologous organs?
ANS. Those organs of different plants and animals are similar in shape but perform different functions are called homologous organs.
Q.3 What do you understand about analogous organs?
ANS. Those organs which perform similar functions but have different structures in different organisms are called analogous organs.
Q.4 Name an analogy organ between animals?
ANS. Wings of bat and wings of a bird.
Q.5 Name a homology organ between plants?
ANS. Spines of Opuntia and Pitcher of pitcher plants.
Q.6 Name a homology organ between animals?
ANS. Forelimbs of lizard, frog, human, and bird.
Q.7 Sweet potato and potato have what kinds of organs?
ANS. Analogous organ
Q.8 What do you know about nodes?
ANS. Potatoes have eyes-like structures called nodes.
Q.9 Butterfly wings and bird wings have what kind of organ?
ANS. Analogous organ
Q.10 What are the things that covered birds’ wings?
ANS. Flash, skin, and feather.
Saquib Siddiqui is a Mechanical Engineer with expertise in science projects and experiments. Saquib’s work focuses on integrating scientific concepts with practical applications, making complex ideas accessible and exciting for learners of all ages. In addition to his practical work, Saquib has authored several articles, research papers, and educational materials.
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