Our human body has various special ways of responding to antigens. Mostly these ways are classified into two categories: 1  Antibody-mediated immunity in which the different antibodies that are dissolved in lymph, blood and other fluids of the body bond with the antigen and activate a response (humoral immunity).he most important role in immunization is played by white blood cells or lymphocytes which are usually produced in the bone marrow and are then transported to various organs for their protection. Cell mediated immunity is also a part of this whole defense system.
Definition: A square is a quadrilateral with all four angles right angles and all four sides of the same length. So a square is a special kind of rectangle, it is one where all the sides have the same length. Thus every square is a rectangle because it is a quadrilateral with all four angles right angles. However not every rectangle is a square, to be a square its sides must have the same length. Penny.
As a polygon, a quadrilateral has a two-dimensional shape with four sides and four angles. Examples of quadrilaterals are rectangles, parallelograms, squares and rhombuses. Only squares and rhombuses are considered regular quadrilaterals because their sides are all the same length. A square is a quadrilateral with four congruent sides, with the opposite sides parallel, and four right angles. A rhombus has four congruent sides that do not form right angles. Learn more about Shapes