In this post we are going to discuss about Plant Tissue. For the post of Morphology and Anatomy of Frog, Click here . Plant Tissue : •A tissue is a group of cells having a common origin and usually performing a common function. •A plant is made up of different kinds of tissues. •Tissues are classified into two main groups, namely, meristematic and permanent tissues based on whether the cells being formed are capable of dividing or not. For the post of Morphology and Anatomy of Cockroach, Click here . Meristematic Tissue : •Growth in plants is largely restricted to specialised regions of active cell division called meristems (Gk. meristos: divided). •Plants have different kinds of meristems. •The meristems which occur at the tips of roots and shoots and produce primary tissues are called apical meristems. •Root apical meristem occupies the tip of a root while the shoot apical meristem occupies the distant most region of ...
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
In this post we are going to discuss briefly about the Skeletal System and Joints. Skeletal System : •Skeletal system consists of a framework of bones and a few cartilages. •This system has a significant role in movement shown by the body. •Imagine chewing food without jaw bones and walking around without the limb bones. •Bone and cartilage are specialised connective tissues. •The former has a very hard matrix due to calcium salts in it and the latter has slightly pliable matrix due to chondroitin salts. •In human beings, this system is made up of 206 bones and a few cartilages. •It is grouped into two principal divisions – the axial and the appendicular skeleton. •Axial skeleton comprises 80 bones distributed along the main axis of the body. •The skull, vertebral column, sternum and ribs constitute axial skeleton. •The skull is composed of two sets of bones – cranial and facial, that totals to 22 bones. •Cranial bones a...
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