The range of variations in the physical and chemical environment under which an ecosystem can survive is known as its range of .

Astudent observes a star from two positions of earth in its orbit, in summer and winter, and measures the change in the position of the star. which of these can be best calculated by this method?

Which best describes a benefit of using dna technology in medicine? a) medicine can be produced in mass quantities. b) medicine can be distributed at a reduced cost. c) medicines have fewer side effects. d) medicines are resistant to antibiotics.

Which of the following types of stars are dim but can have high surface temperatures? giants main sequence stars supergiants dwarfs