Answer: A. The process of synthesizing organic molecules from a mixture of gases has been successfully modeled in the laboratory.
Explanation:
The Miller–Urey experiment or Miller experiment was a chemical experiment that simulated the conditions thought at the time to be present on the early Earth and tested the chemical origin of life under those conditions. The experiment at the time supported Alexander Oparin's and J. B. S. Haldane's hypothesis that putative conditions on the primitive Earth favoured chemical reactions that synthesized more complex organic compounds from simpler inorganic precursors. Considered to be the classic experiment investigating abiogenesis, it was conducted in 1952 by Stanley Miller, with assistance from Harold Urey, at the University of Chicago and later the University of California, San Diego and published the following year.
After Miller's death in 2007, scientists examining sealed vials preserved from the original experiments were able to show that there were actually well over 20 different amino acids produced in Miller's original experiments. That is considerably more than what Miller originally reported, and more than the 20 that naturally occur in life. More recent evidence suggests that Earth's original atmosphere might have had a composition different from the gas used in the Miller experiment, but prebiotic experiments continue to produce racemic mixtures of simple-to-complex compounds under varying conditions.
Answer:
They established of a postal system
The spread of weapons that used gunpowder
The extension of the grand canal in China
The invention of new medicines
Explanation:
The Pax Mongolica refers to the stabilizing impacts of the conquests of the Mongol Empire on the social, cultural and economic life of the citizens of the vast Eurasian territory that the Mongols conquered in the 13th and 14th centuries.
The provided question is incomplete, the correct and complete question is as follows:
Choose the answer that best completes the sentence below.
Scientists group materials together ____________ it is easier to compare and study them that way.
A however
B but
C although
D because
Answer:
The correct answer is - option D because.
Explanation:
Researcher and scientists tries to group material together on their similarities and difference to one another which makes it easier to study and compare various type of materials.
It is the one of major reasons to differentiate materials between groups like liquids state, gases state, plasma state and solid state materials. One can easily see the difference and comparison is very clear on this type of grouping of materials.
Thus, the correct answer is - option D.
There are 3 sources of calories (or energy), which are also known as macronutrients: carbohydrates, protein, and fat. Of these three, carbohydrates are the body's preferred source of energy. Carbohydrates break down into glucose, which is an immediate source of energy especially for the brain and muscles.