Scientific consensus supports the idea that living organisms require oxygen. then, a scientist discovers a type of bacteria that metabolizes sulfur instead of oxygen, and thus survives in environments without oxygen. the scientist concludes that a diverse group of many different organisms could live in an oxygen-free environment. why should are some scientists skeptical of the scientist’s results and conclusion?

What was dr. willem johan kolff’s first step in using the scientific process to invent the hemodialysis machine? he built the machine and tried it with various patients, collecting data about its effectiveness. when a patient’s kidneys failed, he wondered if it would be possible to perform kidney functions with an external machine. he researched and collected data about numerous patients who exhibited symptoms of kidney failure. he drew conclusions from studies of various symptoms of kidney failure, and drew a design for the ideal external blood-processing machine.

How are the testes and ovaries similar? a. both produce sex cells. b. both connect internal reproductive organs to the exterior. c. both transport sex cells from their site of production. d. both store mature sex cells.

What organelle other than the nucleus houses dna in a eukaryotic cell?