The following points highlight the four main parts of mature egg of birds. The parts are: 1. Plasma Membrane 2. Primary Egg Membranes 3. Secondary Egg Membranes 4. Ooplasm. Mature Egg: Part # 1. Plasma Membrane: The mature egg is covered by a plasma membrane which is the unit membrane. It is composed of an outer and an inner layer [...]
Introduction to Invertebrates Phyla: The invertebrates include those which are without backbone as opposed to vertebrates in which a series of vertebrae constitute a backbone, but this division of the animal kingdom into invertebrates and vertebrates is largely a matter of convenience. The invertebrates constitute about 90 per cent of the known animals which number over a million. Vast and [...]
The following points highlight the twenty-one general characteristics of invertebrates. Some of the characteristics are: 1. Habitat 2. Numerical Strength 3. Shape 4. Size 5. Symmetry 6. Grades of Organization 7. The Presence or Absence of Germ Layers 8. Simple Integument 9. Multiple Movement Device 10. The Presence or Absence of Segmentation and Others. Characteristic # 1. Habitat: All the [...]