<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:
2% of the progeny will be double crossovers for the trihybrid test cross
Explanation:
By knowing the positions of genes, we can estimate the distances in MU between them per region.
- Genes A and B are 10 map units apart (Region I)
- Genes B and C are 20 map units apart (Region II)
- Genes A and C are 30 map units apart
----A-------10MU--------B-------------20MU-------------C---
Region I Region II
We can estimate the recombination frequencies by dividing each distance by 100.
• recombination frequency of A-B region = 10MU / 100 = 0.10
• recombination frequency of B-C region = 20MU / 100 = 0.20
Now that we know the recombination frequencies in each region, we can calculate the expected double recombinant frequency, EDRF, like this:
EDRF = recombination frequency in region I x recombination frequency in region II.
EDRF = 0.10 x 0.20 = 0.02
2% of the progeny will be double crossovers for the trihybrid test cross
Answer:
Using the food chain which originates from the sun's energy.
Explanation:
I would think it would be C
