Answer:
The tubule adjusts the level of salts, water, and wastes that will leave the body in the urine. Filtered blood leaves the kidney through the renal vein and flows back to the heart.
Pee leaves the kidneys and travels through the ureters to the bladder. The bladder expands as it fills.
True
There is not doubt about Charles Darwin merits as one of the most important scientifics. His wide research of the living organisms and biodiversity lead him to formulate the natural selection and evolution theories.
Answer:
The Earth is essentially a closed system; it obtains lots of energy from the Sun but the exchange of matter with the outside is almost zero. Isolated systems can exchange neither energy nor matter with an outside system.
The Precambrian was originally defined as the era that predated the emergence of life in the Cambrian Period. It is now known, however, that life on Earth began by the early Archean and that fossilized organisms became more and more abundant throughout Precambrian time.
