Gastrulation: Germ Cell Formation

<p>It allows for the maintenance of gonadal sex. (A)</p> Signup and view all the answers

<p>Wnt and Notch signaling (C)</p> Signup and view all the answers

<p>To ensure the continuation of species through reproduction (C)</p> Signup and view all the answers

<p>Third week of development (D)</p> Signup and view all the answers

<p>Bone Morphogenetic Proteins (BMPs) and Wnt signaling molecules (B)</p> Signup and view all the answers

<p>Functional gametes (sperm or eggs) (B)</p> Signup and view all the answers

Specialized cells responsible for producing sperm and egg cells, essential for reproduction.

The process of germ cell formation, where precursor cells develop into functional sperm or egg cells.

The earliest precursors of sperm and egg cells, set aside early in embryonic development.

The location where PGCs are initially specified in the early embryo.

The process where signals from the extra-embryonic mesoderm induce the formation of PGCs.

Proteins involved in the induction of PGCs, which are crucial for their specification.

The journey PGCs take from their origin in the epiblast to the developing gonads.

A chemical signal that guides PGCs during their migration, attracting them to the gonads.

The process of reprogramming primordial germ cells (PGCs) to erase their somatic cell memory, making them capable of becoming gametes (eggs or sperm).

The process of silencing one of the X chromosomes in female cells. This ensures that females have the same amount of X-linked gene expression as males, who have only one X chromosome.

Signaling pathways like Wnt and Notch play crucial roles in determining whether PGCs will develop into sperm-producing cells (spermatogonia) or egg-producing cells (oogonia).

A molecule that influences the timing of meiosis, the process of cell division that produces gametes. It affects when germ cells enter the prophase I stage of meiosis.

The final determination of a germ cell's sex depends on the genetic sex of the embryo. This happens when the gonadal ridges develop into either testes (male) or ovaries (female).

Cells in the testes that support sperm development. They are essential for the production of hormones like testosterone.

Cells found in the testes that produce testosterone, the male sex hormone. They are crucial for the development of male sexual characteristics.

Cells found in the ovaries that support egg development. They are essential for follicle formation and estrogen production.

The process of producing sperm cells in the testes.

The process of producing egg cells in the ovaries. This process begins in the fetus and continues until menopause.

The process of transforming the neural plate into the neural tube, which later forms the brain and spinal cord.

The region of the ectoderm that thickens to form the neural plate, induced by signals from the notochord and underlying mesoderm.

Growth factors like BMP inhibitors that signal the ectoderm to differentiate into the neural plate.

The process of the neural plate elongating along the head-to-tail axis, with edges rising to form folds.

Raised edges of the neural plate that curve towards each other, containing neural crest cells.

The central depression in the neural plate that deepens and ultimately closes to form the neural tube.

Cells located at the edges of the neural folds that give rise to sensory neurons, ganglia, and parts of the heart.

The failure of the forebrain to divide properly, resulting in a single, undivided brain structure.

A condition where the lower part of the body is underdeveloped, potentially affecting the legs, feet, and sometimes internal organs.

The developmental process that occurs during the fourth week of human gestation and is crucial for forming the central nervous system.

The process of forming somites, the building blocks of the vertebral column, ribs, and associated muscles and skin.

A pair of blocks of mesodermal cells that form on either side of the neural tube during embryonic development.

The part of a somite that gives rise to the muscles (myotome) and the dermis of the skin (dermatome).

The part of a somite that forms the vertebrae and ribs of the axial skeleton.

A signaling pathway that plays a key role in the segmentation of the paraxial mesoderm into somites.

The process by which the mesoderm divides into distinct blocks of tissue, forming somites.

The direction of somite formation, starting from the head (cranial) and moving towards the tail (caudal).

The rate of somite formation in humans, approximately 3 pairs of somites form each day.

The total number of somites formed in a human embryo, usually 42 to 44 pairs.

The developmental stage when most somites have formed, around day 30 of human embryonic development.

The space within the embryo that develops from cavities formed within the lateral mesoderm, eventually becoming a continuous cavity.

The outer layer of the mesoderm that forms the lining of the body cavities.

The inner layer of the mesoderm that covers the developing organs.

The formation of new blood vessels from angioblast cells.

Precursor cells that differentiate into the endothelial cells of blood vessels. Found in blood islands during the early development of the circulatory system.

Precursor cells that differentiate into blood cells, like red blood cells. Located in blood islands during the development of the cardiovascular system.

The location where the first blood vessels form during embryonic development. Serves as the initial circulatory system for the embryo.