The two ways cell division can occur are through mitosis and meiosis. In mitosis, a cell produces two clones of itself, each with the same number of chromosomes. In meiosis, a cell will produce four cells called gametes through the process of spermatogenesis and oogenesis. Gametes are most commonly known as sperm cells in males and egg cell in females. Unlike mitosis, the gametes that meiosis produces are not clones of the original cell as each gamete has exactly had as many chromosomes of the original cell and are all different from one another (siblings). Mitosis can …show more content…
Spina Bifida is a birth defect where a portion of the neural tube fails to develop or close properly. This causes defects in the spinal cord and in the bones of the spine. In Anencephaly, the development of the brain and bones of the skull are hindered when the neural tube fails to close properly. The developing brain and spinal cord are exposed to the amniotic fluid that surround the fetus in the womb, this causes the nervous system tissue to degenerate. People who suffer from anencephaly are missing parts of their cerebrum, cerebellum and the bones of the skull.
ESSAY - Define and explain the 3 processes that characterize central nervous system growth during the prenatal fetal period (proliferation, migration and differentiation), and compare them to the processes that characterize central nervous system development during infancy (synaptogenesis, and synaptic …show more content…
Synaptogenesis is the formation of synapses and neurotransmitter receptors between neurons. The foundation of neurotransmitter and synapse development began during the cell differentiation stage and continues in synaptogenesis. Unlike the cell differentiation stage, synaptogenesis can occur after the fetal/infancy period. Neurons begin to undergo synaptic pruning, to a certain extent, during and mainly, after, synaptogenesis. Synaptic pruning is the process by which extra neurons and synaptic connections are eliminated in order to increase the efficiency of neuronal transmissions. After the proliferative, migration, differentiation and synaptogenesis stages individuals are left with far more neurons and synapses than are functionally needed. Synaptic pruning is paramount in developing a fully functioning peripheral and central nervous system. Unlike the fetal development stages which end after days or months of development, both synaptogenesis and synaptic pruning continue to occur well past infancy into adolescence and