Which of the following statements is true a The blastomeres

Which of the following statements is true? a. The blastomeres rearrange themselves to form three germ layers during metamorphosis. b. Gastrulation produces a gastrula with ectoderm, mesoderm, and endoderm. C. The blastocoel forms during morphogenesis. d. The neurula forms a gastrula during fertilization. e. Cell divisions are very slow during cleavage.

Solution

1. Gastrulation produces gastrula with ectoderm, mesoderm and endoderm

2. During morphogenesis, cells form tissues with defined shape.

3. Nervous system

Heart, blood cells, notochord - mesoderm

Lung - endoderm

4. The blastomere move and form the 3 germ layers

The blastula on gastrulation forms gastrula with 3 germ layers.

5. Epithelial or mesenchymal

Epithelial - tightly packed cell and forms a sheet E.g.: skin

Mesenchymal cell - loosely associated cells surrounded by a matrix. E.g.: tissues of circulatory system

6. Specialised features develop from general ones.

Von Baers law states that

\"Less general characters are developed from the more general, until finally the most specialized appear.\"

7. Cell shape changes

Morphogenesis - Process that controls the formation of cells\' shapes.