Follow me on Twitter

-
Follow me on twitter 

Comments

Post a Comment

Popular posts from this blog

ANIMAL KINGDOM Part-1, NCERT Class-11

-
Basis of Classification: Levels of Organisation *All members of Kingdom Animalia is multicellular •Cellular Level of Organisation:   1) Cells are arranged as loose aggregates   2) Some division of labour occur among the cells e.g. Sponges •Tissue Level of Organisation: 1) Cells performing the same function are arranged intotossues e.g. Coelenterates •Organ Level of Organisation: 1) Tissues are grouped together to form organs, each specialised for a particular function e.g. Platyhelminthes •Organ System Level of Organisation: 1) Organs have associated to form functional systems, each system concerned with specific physiological function  e.g. Annelids to Chordates Types in case of Organ System Level of Organisation: •Incomplete Digestive System:      Possess only one single opening outside the body which act as both mouth and anus e.g. Platyhelminthes •  Complete Digestive System:     Possess two openings • Open Type Circulatory System: ...
Read more

ANIMAL KINGDOM Part-3, NCERT Class-11

-
Image
Body Organisation Animals have three germinal layers of cell in their embryonic stage. Those layers are called Ectoderm , Endoderm and Meroderm . On the basis of presence of mesoderm or middle layer, animals are divided into two  categories- • Diploblastic: Animals that have only two embryonic layers are called diploblastic body organisation. They lac the mesoderm layer. An undifferentiated layer called mesoglea is present instead of mesoderm e.g. Coelenterates • Triploblastic: Animal that have all three embryonic layers are called to have triploblastic body organisation. Mesoderm is present in between Ectoderm and Endoderm. e.g. Platyhelminthes to Chordates   Body organisation (Germinal layers) (a) Diploblastic (b) Triploblastic Click  here  for part 1 of this chapter Click  here  for part 2 of this chapter
Read more

ANIMAL KINGDOM Part-2, NCERT Class-11

-
Image
Symmetry • Asymmetrical: Any plane that passes through the center doesn't divide the following organism into two equal half e.g. sponges • Radial Symmetry: Any plane that passes through the central axis of the body divides the following organism into two equal halves e.g.   Coelenterates , Ctenophores, Adult Echinoderms      Radial Symmetry( Hydra sp. ) • Bilateral Symmetry: The body of the following organism can be divided into two equal halves if and only if the cutting plane pass through in a particular way through central axis e.g. Annelids , Arthropods etc. Bilateral Symmetry( Brachyura sp.) Click  Here  for part 1 of this chapter
Read more