1. Review: What is a stem cell versus a specialized cell? Explain the factors that contribute to a stem cell becoming specialized.
A stem cell is an undifferentiated cell which hasn’t yet participated in gene expression while a specialized cell only synthesizes proteins from certain strands of genes to execute a/some unique function(s). A stem cell’s differentiation depends on a certain organ’s need and the number of stem cells available. 2.What role does your cell play in the body? An ovum is responsible of fusing with a sperm to give rise to a new life, reproduce and pass down genetic information. 3.Which embryonic tissue layer did it come from? It comes from germ cells which is separate from the three main tissue layers.
4.Where in the body would you expect to find the stem cells that produce these specialized cells? In the ovary. 5. Describe the specialized features of your cell (cell structures, shape, etc.) An oocyte is spherical and has a well-defined cell membrane.
It doesn’t contain any organelles besides a nucleus and is surrounded by follicle cells. 6. Describe the process of development.
Egg cells go through a process called oogenesis to become an ovum. 1. Primordial embryonic germ cells move into the ovary;2. The germ cells grow and develop into oogonia (2n);3.
Out of 7 million oogonia, 6 million die and the remainders go through Prophase I in the first few months of fetal development. The oocytes after this stage are called primary oocytes and they are frozen until a female reaches puberty;4. Every time a female goes through puberty, only one of the primary oocytes matures, completes Meiosis I inside its incubation center composed of follicle cells and is ejected into the fallopian tube to divide via Meiosis II. This process is called meiotic maturation. ** Each meiotic division results in two cells, one of them which is an oocyte with a majority of the cytoplasm and the other one which is a polar body with little cytoplasm that will degenerate and die. This method helps the oocyte to effectively halve its genetic information while also preserving most of its cytoplasm.5.
The mature oocyte (aka ovum) fuses with a sperm and becomes a zygote (2n).