Scientists believe that during its early formation, Earth's atmosphere
contained little, if any, oxygen.
Fossil and rock records suggest
that by about two billion years
ago, Earth's atmosphere was
oxygen rich and that organisms
with complex cells existed. Many
scientists think that these organisms
released oxygen, changing the
composition of Earth's atmosphere.
Which process provides the most probable explanation of how the organisms released oxygen into the Earth's atmosphere?
А.
The cells produced sugar and oxygen during the process of photosynthesis.
The cells gave off oxygen during cell division as they rapidly reproduced.
B
The cells broke down carbon dioxide and oxygen to obtain energy in cellular respiration
The cells combined nitrogen and hydrogen to produce oxygen in the process of respiration

Researchers determine that the biodiversity in a woodland region is declining. they identify two major threats to the region's biodiversity, a method to address each threat, and the expected outcome of each method. this information is shown in the table. threat method number of species that benefit number of years to see benefit habitat fragmentation reforestation 450 8 introduced prey species biological augmentation 150 2 which statement is an accurate explanation of the information in the table? a. biological augmentation would benefit only a few species because it is typically not very effective. b. biological augmentation would take less time to be effective because it targets the majority of prey species. c. reforestation would take the longest time to be effective because trees take several years to grow. d. reforestation would not benefit many species because most forest species live on the ground.

What substance acts to prevent sudden ph changes in bodily fluids?

Research question: why are the carrots that grew on the left side of the garden larger than the carrots that grew on the right side of the garden? which hypothesis is based on this research question? a comparison of people with gardens to people without gardens will show who is likely to live longer. b. carrots are thought to be good for your eyesight and should be eaten regularly. c. carrots that are provided lots of sunlight grow to a larger size than carrots grown in the shade. d. eating fresh vegetables every day is a healthy thing to do.