Which of the following is an example of heat transfer by radiation?
A. an electric space heater warming a room
B. the sun warming the earth
C. a fire warnings a group of campers
D. all of these

Which element is used in photosynthesis found in atmosphere and fixed by bacteria?

Hurry which of these is true about index fossils? a) are very scarcely found b) used as guides in relative dating c) found in the youngest layer of the rock d) used as reference points in absolute dating

One gene can influence trait(s). one trait can be determined by gene(s).