No, although there are several theories with increasing evidence, there is still no way to know for sure how it occurred. The great mystery of the beginning of universe is way too vast and vague. Theories can only be proven by presenting a solid proof, but great creations such as universe itself doesn't have to be solved. Various possibilities must have happened or there must be a one conclusion leading to its existence; but moreover, it is not our problem to solve. The confirmation of beginning of its existence will only feed the curiosity of humans.
Answer:
filum terminale
The filum terminale is a thin strand of pia mater that helps anchor the conus medullaris to the coccyx
Sickle cell anemia is a genetic condition that distorts the shape of the hemoglobin. This reduces the capacity of the red blood cells to carry oxygen. Another effect is that the distorted red blood cells come together forming a heavy and compact collection of cells that can block the flow of blood. The sedimentation rate is increased by sickle cell anemia.
Models are used to stimulate reality and make predictions
Photosynthesis and cellular respiration are opposites