Scientists are monitoring a whale's weight by observing its weight change once a week, over a 4 week period. how much has the whale's weight changed over the entire 4 weeks?

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

hope this !

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms

not always but somethings can be reproduced in a laboratory.