Answer:
1. Life, exist 2. pre-existing cells.
Explanation:
<span>A moist environment because physical weathering processes such as oxidation take place most quickly in the presence of water.
There are three types of weathering, physical, chemical, and biological.
For the physical weathering, there are two main types. Freeze-thaw cycles and exfoliation. Obviously the freeze-thaw cycles require water and the exfoliation generally happens through thermal expansion and contraction which doesn't require water. But since neither of these mechanisms were observed, that doesn't indicate if the area was wet or dry. Biological weathering is caused by plants or animals breaking down rocks via chemical (acid) or mechanical (root growth) means. Life generally indicates the presence of water, but since this form of weathering wasn't observed, we still don't have enough data. Chemical weathering is caused by rain water reacting with the rocks to form new minerals and salts. There are several types such as acidic rainwater dissolving part of the rock, and oxidation. With this in mind, let's take a look at the available options.
A moist environment because there is a greater density of oxygen in the atmosphere in the presence of water.
* Yes, we need a moist environment, but the density of oxygen is fairly constant world wide regardless of how moist or dry the environment is. So this is a bad choice.
A moist environment because physical weathering processes such as oxidation take place most quickly in the presence of water.
* Water speeds up chemical weathering of all types. So this is the correct choice.
A dry environment because the increased albedo of deserts encourages physical weathering processes such as oxidation.
* Yes, the increased albedo of deserts does speed up spalling, but oxidation is a CHEMICAL weathering process, not a PHYSICAL one. So this is a bad choice.
A dry environment because in the absence of water oxidation is the dominant weathering process.
* Water speeds up oxidation quite a bit. And since the observed oxidation is thick, there's been quite a bit of weathering. So this is a bad choice.</span>
Answer:
Robert Hazen’s studied enviromental and biological processes that might have been critical for life, and also for the formation of approximately two-thirds of Earth's mineral species (see Hazen et al., 2008; Gonzalez & Richards 2020)
.
Explanation:
Hazen provided evidence about how first organic molecules were generated on the primitive earth millions of years ago. He observed that high-pressure hydrothermal vents may provide food for underwater ecosystems. It represents a piece of critical evidence on the origin of life.
You can read these articles that are certainly clarifying in the description of his experiments and discoveries:
1- Hazen, R. M., Papineau, D., Bleeker, W., Downs, R. T., Ferry, J. M., McCoy, T. J., ... & Yang, H. (2008). Mineral evolution. American Mineralogist, 93(11-12), 1693-1720.
2- Gonzalez, G., & Richards, J. W. (2020). The privileged planet: how our place in the cosmos is designed for discovery. Gateway Editions.
Label O is organic material, label A is topsoil, label B is subsoil and label C is weathered rock. They represent different soil layers.
<h3>Soil layers</h3>
Soli layers, also called horizons, refer to the different layers observed on the ground.
The topsoil is a layer of soil composed of a mixture of sand, silt, clay and organic material referred to as humus.
Weathering rocks refer to the dissolved rocks and/or minerals on the Earth's surface.
Subsoil refers to the layer under the topsoil on the surface of the ground.
Learn more about soil layers here:
brainly.com/question/1933157
During the second gap, or G2 phase, the cell continues to grow in size and produce proteins necessary for cell division. Microtubules, filamentous internal structures, necessary for separating the chromosome copies are made during this phase. The second internal checkpoint that determines if the cell can continue through its cycle occurs in G2. While the G1 checkpoint checks to verify DNA is error free before replication, the checkpoint in G2 confirms the new DNA is error free after replication
