And I will use the test market to derive a means to make my product an even bigger success.â. To use the test market to improve the productivity of the marketing plan requires a research design that tests variations in the plan. âThere is more to be learned from test marketing than an estimate of trial and repeat.
The mesoderm is one of the three major layers in a developing embryo, referred to as germ cell layers. Other germ cell layers are the endoderm and ectoderm. When the embryo develops, different organs and body parts develop from these germ cell layers.
Each of the three primary germ layers will form a different set of specific organs and tissue types in the animal. The ectoderm will form the nervous system, the epithelial cells of the mammary glands, the lens of the eyes, hair, pigment cells and the epidermis of the skin.hese three layers, the endoderm, the ectoderm and the mesoderm, are called the primary germ layers. After gastrulation, the cup-like embryonic stage that contains at least two distinct germ layers is called the gastrula.