Final answer:
The correct ectodermal marker genes are B) Nestin, Sox1, Pax6. These genes are expressed in the ectoderm layer of an embryo, leading to the development of the nervous system and epidermis. They are regulated by growth factors and are part of the differentiation process, which is overall orchestrated by master control genes like Hox genes.
Step-by-step explanation:
Ectodermal marker genes are those genes that are expressed in cells originating from the ectoderm layer during embryonic development, directing them to differentiate into specific structures. The correct answer to which are ectodermal marker genes is B) Nestin, Sox1, Pax6.
In the development of the embryonic germ layers, the ectoderm gives rise to the nervous system, including the brain, spinal cord, and epidermis, along with associated structures such as hair and nails. Ectodermal marker genes like Nestin, Sox1, and Pax6 are critical in the early stages of this process as they regulate the formation of embryonic structures ascending from the ectoderm, particularly those involving the nervous system and sensory organs. These genes are part of a broader developmental context regulated by growth factors in the embryonic environment, signaling the ectodermal cells to form neural plates, which further differentiate into more specialized cell types within the ectodermal lineage.
During embryonic development, Hox genes play a pivotal role as master control genes, influencing the expression of large numbers of other genes to determine the course of development. While Hox genes are critical in body segment differentiation and are expressed in different body segments to ensure proper formation, they are not considered to be specific ectodermal markers.