Basis Of Classification
Chapter Name : Animal Kingdom |
Sub Topic Code : 103_11_04_01_03 |
Topic Name : Basis Of Classification |
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Sub Topic Name : Diploblastic And Triploblastic Organization |
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Introduction
Based on the number of layers the cells are arranged in the embryo, animals are divided into diploblastic and triploblastic.
Pre-Requisites:
Levels of organization.
Activity:
See the sketch of the different layers of the embryonic cells in your NCERT textbook (for class 11), fig.4.2. Observe the various embryonic layers.
Real Life Question:
Does it really matter how the cells were arranged when we were just embryos?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Diploblastic Triploblastic Ectoderm Endoderm Mesoderm Mesoglea | Animals with cells arranged in two embryonic layers. Animals with cells arranged in three embryonic layers. External layer of cells in embryo. Present both in diploblasts and triploblasts. Internal layer of cells in embryo. Present in both diploblasts and triploblasts. Cell layer between endoderm and ectoderm. Present only in triploblasts. Undifferentiated layer between endoderm and ectoderm. Present in diploblasts. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Observe various figures of embryonic germ layers. | Try to spot diploblastic and triploblastic organisms. |
Places to visit :
Biology Laboratory
Practical examples around us
| Examples | Explainations |
|---|---|
| Humans are triploblasts. |
What you learn in Theory:
Different germ layers formed in the embryonic stage of animals.
What you learn in Practice:
Different organisms have different cell layers in the embryonic stages that form various organs eventually.