Which were the earliest oxygen-producing life-forms?

a. cyanobacteria.

b. seaweed.

c. dinosaurs.

d. ferns.

What is the average for the following set of measurements? 27°C, 12°C, 31°C, 19°C, 23°C, 11°C, 17°C O A 7°C O B. 140°C O C. 28°C O D. 20°C

Which quality makes Earth particularly well-suited to support life? A. It has only one natural satellite. B. It is between two planets of similar size. C. It contains the right amount of carbon, nitrogen and oxygen. D. It is only 5 billion years old.

What does it mean when pathogens are referred to as contagions?

Jonas states four interesting facts about bones. Which of Jonas's statements is incorrect? A. Some bones have holes through them. B. Bones are made mostly of sugars. C. Bones are made of layers. D. Bones can have different shapes.

Which of the following organelles convert solar energy into glucose and oxygen?

How would you solve 5x + x - 3x > - 12

How can individuals play a role in the evolution of an entire species

Which of these are found in the lymph? A. red blood cells B. white blood cells C. antibiotics D. platelets

The visual predation hypothesis proposes that:a) better vision allowed for better access to fruits and small insects b) primate traits arose as adaptations to preying on insects and small animals c) species could see predators from farther away,

A researcher wants to know whether children eating a high-protein breakfast will have a higher test grade. half of the children in the study eat a high-protein breakfast while the other half eats their normal diet.