11-09-2022
Biology

contestada

What was Earth's early atmosphere like before cyanobacteria?

Respuesta :

ogando12071 ogando12071

11-09-2022

Answer:

Oxygen-free

Explanation:

Before about 2.4 billion years ago, Earth was a virtually oxygen-free environment. The appearance of cyanobacteria, or blue-green algae, changed all that. Cyanobacteria injected the atmosphere with oxygen, setting the scene for the development of complex life as we know it.

Answer Link

Otras preguntas

2 Points What charge would an ion have if it had more electrons than protons? A. It would be neutral, since electrons would be outside the nucleus. B. It would

What type of characterization is used when the audience learns about a character based on the character's appearance, dialogue, actions, and private thoughts? A

All organic molecules contain the element carbon. True False VTC ASV COD UP

Please answer this correctly

(What does the environment have to do with an animal's survival?)

which letter be represents an archipelago? A. e B. c C. b D. a

50 points. Find the area of the shaded regions:

What can you infer about the effect of dating violence on victims from the text? A.Youths are more likely than adults to be victims of dating violence. B.Males

What is the length of a radius if the diameter is 27 meters long ?

Help me jdjdjdjjdjdjjd