The first organisms to appear on Earth did not need?

a.

oxygen.

c.

cells.

b.

nitrogen.

d.

chemicals.

Ms. Crawford gave the following instructions to her science class: • Place an empty water bottle on the table and remove the lid. Carefully pour 10 ml of vinegar into the bottle.

Trees are important in maintaining air quality, because they act like a filter, drawing particles from the air.

Which of these is not a factor that influences animal growth? a availability of food b gravitational force c genetic information d inherited diseases

When Carter first moved into his neighborhood, he noticed hundreds of frogs on the roads after a rain storm. Lately, Carter has seen less than four or five frogs on his drive through the neighborhood.

A scientist uses materials in her lab to turn one piece of dna into 100 copies

An electric clothes dryer draws 22 A of current from a 240-V wall outlet. How much power, in watts, does it use?

Which phase do you spell spend time making organelles and completing tasks such as producing proteins

How do you think an ecosystem can be reestablished in an area after a disturbance happens?

At which PH is pepsin most active?

Compare how a cell maintains homeostasis with how the human body maintains homeostasis