Which were the earliest oxygen-producing life-forms?

a. cyanobacteria.

b. seaweed.

c. dinosaurs.

d. ferns.

As the water crisis gets worse, which of the following does NOT increase? A) The number of water consumers B) The demand for water C) The supply of clean water D) The price of water

Which of the following are not properties of carbon?

Which term describes all the individuals of one species that occupy an area?

In spermatogenesis, meiosis results in the formation of

All waves have which four characteristics? A. wavelength, frequency, amplitude, speed B. wavelength, crests, amplitude, speed C. crests, troughs, amplitude, speed

What are reasons scientists use models? To study objects far away To study objects too large To study objects too small. To study objects easily found in a lab. To study events that take place over long periods of time.

1. true false Carbon atoms form the building blocks of most living things.

Inhibiting enzymes involved in cell wall synthesis leads to which of the following? A) cell death by osmotic lysisB) a reduction in protein synthesisC) the incomplete synthesis of the bacterial cell wallD) a reduction in the amount of usable energy

In the 20th century where did the most ecologically destructive oil spill in the US

Which of the activities listed below are functions of the Lymphatic System? 1 transports lipids to the blood 2 transports lipid-soluble vitamins to the blood 3 drains excess interstitial fluid from tissue spaces and returns it to the blood 4