Sara's mother gets a flat tire on her car while driving Sara to school. They use a jack to

change the flat tire. It exerts a force of 5,000 newtons to lift the car 0.25 meters. How much

work is done by the jack? Use commas as appropriate.

Unlike food webs, food chains a. involve a network of complex interactions among various organisms in an ecosystem. b. contain consumers that eat producers. c. contain autotrophs that make their own food. d.

Which of the following describes a reason for making a prediction when doing a controlled experiment? a. to identify a useful and reliable source of scientific information b. to prove that a hypothesis is true before it is tested in an experiment c.

By comparing fossils of a species from long ago to those of today, we can conclude that

How does the electron transport chain active during the Krebs cycle affect the hydrogen ion concentration in a mitochondria

Burning a candle is a chemical change. What is the primary evidence that burning the candle is a chemical reaction? A) change in odor B) change in color C) formation of a solid D) temperature change

True or False: The humidity of a desert is most likely described as arid. TH

Describe the process of desertification

During transcription in eukaryotes, a type of RNA polymerase called RNA polymerase II moves along the template strand of the DNA in the 3'→5' direction.

A plant species live in an area with limited sunlight

Which statement is true of the nucleus of a cell