Which of the following statements is an identifying characteristic of a mixture?
a. a mixture must have a definite composition by weight
b. a mixture can consist of a single element
c. a mixture must be homogeneous
d. a mixture can be separated by physical means

2points what is the term for a female reproductive cell? a. egg b. chromatid c. allele d. fertilization

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.

Adrought killed all the plants in an agricultural farmland. gradually, due to wind and some birds for. nearby areas, new plants started sprouting l. what stage of succession was taking place in the farmland? a) competition b) nudation c) ecesis d) reaction e) migration