I don't really know but I pick b.have always been vestigial.
The answer would be sandstone
Answer:
C
Explanation:
The definition of microtuble is: "a microscopic tubular structure present in numbers in the cytoplasm of cells, sometimes aggregating to form more complex structures." (google) Therefor, it would not be a part of mitosis prophase II.
What are the nephron?
Nephrons are the functional unit of the kidney. There are about two million nephrons in each of our kidneys. Each nephron has a network of glomelural capillaries called glomerulus where blood filtration occurs, and the renal tabule which is where the filtered fluid is converted to urine.
How they work?
The nephrons act as a filter, cleaning our blood. Unwanted metabolites like urea and creatinine are taken from the blood, as well as high amounts of sodium. The filtered fluid flows from inside Bowman's capsule (epithelial cells surrounding the glomerulus) and from there into the proximal tubule (see attached figure at the end). From the tubule, fluid flows into several other ducts until it reaches the ducts where collectors will empty into the renal pelvis.