1.Oparin and Haldane hypothesized that the Earth's early atmosphere was strongly (2 points)

acidic.
oxidizing.
reducing. ~~
ionic.

2.The most significant outcome of the Miller and Urey experiments was that they (2 points)
synthesized living cells from nonliving matter.
disproved the iron-sulfide world hypothesis.
proved that life did not originate on Earth.
synthesized organic molecules from inorganic molecules. ~~

3.It is hypothesized that RNA may have evolved before DNA because RNA molecules (2 points)
were the first molecules synthesized by Miller and Urey.
are more important to genetic inheritance than DNA.
can catalyze a variety of biologically important reactions.~~
are found in more modern cells than are DNA molecules.

4.The evolution from vesicles to true cells was best facilitated by the development of (2 points)
a membrane separating the cell from its environment.
organic molecules, such as carbohydrates and lipids.
self-replicating molecules, such as RNA and DNA.
inorganic molecules, such as nitrogen and oxygen.~~

6.A universal genetic code allows for which of the following? (2 points)
A gene from one species is successfully inserted into another species genome.~~
All organisms to have the same number of genes in their nuclear chromosomes.
The processes of transcription and translation to produce the same proteins in all species.
Descendants of the same common ancestor all have the same chromosomes in their nuclei.

7.Which of the following best supports the endosymbiont theory that present-day eukaryotic cells are descendants of a successful symbiotic relationship between a host cell and an engulfed prokaryote? (2 points)
Chloroplasts and mitochondria replicate in a similar manner as some prokaryotes.
Chloroplasts are necessary for photosynthesis reactions in plant and bacteria cells.~~
Mitochondria and chloroplasts are able to produce ATP molecules to be used by the cell.
Mitochondria use proteins and nutrients produced in other regions of the eukaryotic cell.

a, b, c, e, v,d

wedf

1. Oparin and Haldane hypothesized that the Earth's early atmosphere was strongly reducing.

2. The most significant outcome of the Miller and Urey experiments was that they synthesized organic molecules from inorganic molecules.
3. It is hypothesized that RNA may have evolved before DNA because RNA molecules can catalyze a variety of biologically important reactions.
4. The evolution from vesicles to true cells was best facilitated by the development of a membrane separating the cell from its environment.
6. A universal genetic code allows for a gene from one species to be successfully inserted into another species genome.
7. The endosymbiont theory is best supported by the fact that chloroplasts and mitochondria replicate in a similar manner as some prokaryotes.

To answer these questions, you need to understand the concepts and theories related to the origin and evolution of life. Here's an explanation of each question and how to arrive at the correct answer:

1. Oparin and Haldane hypothesized that the Earth's early atmosphere was strongly:
- To determine the correct answer, you need to know the conditions proposed by Oparin and Haldane for the Earth's early atmosphere. They suggested that the atmosphere was reducing, meaning it had a low concentration of oxygen and a high concentration of hydrogen and other reducing gases. This supported the formation of complex organic molecules necessary for the development of life. Therefore, the correct answer is "reducing."

2. The most significant outcome of the Miller and Urey experiments was that they:
- The Miller and Urey experiments simulated the conditions of the early Earth to investigate the origin of life. They created an atmosphere containing methane, ammonia, water vapor, and hydrogen, and then exposed it to electrical sparks to simulate lightning. The outcome of these experiments was the synthesis of organic molecules, including amino acids, which are the building blocks of proteins. Therefore, the correct answer is "synthesized organic molecules from inorganic molecules."

3. It is hypothesized that RNA may have evolved before DNA because RNA molecules:
- To determine the correct answer, you need to understand the role of RNA in early biological systems. RNA is capable of both storing genetic information and catalyzing chemical reactions. This dual functionality suggests that RNA may have played a crucial role in the early stages of life's evolution. Therefore, the correct answer is "can catalyze a variety of biologically important reactions."

4. The evolution from vesicles to true cells was best facilitated by the development of:
- To answer this question, you need to think about the key developments that allowed simple vesicles to evolve into true cells. One crucial step was the development of a membrane that separated the cell from its environment. This membrane allowed for selective transport and maintained a distinct internal environment. Therefore, the correct answer is "a membrane separating the cell from its environment."

6. A universal genetic code allows for which of the following?
- To determine the correct answer, you need to understand the significance of the universal genetic code. The universal genetic code is a set of codons that specify the same amino acids in all organisms. This allows for the genetic information to be translated and shared between different species. Therefore, the correct answer is "A gene from one species is successfully inserted into another species genome."

7. Which of the following best supports the endosymbiont theory that present-day eukaryotic cells are descendants of a successful symbiotic relationship between a host cell and an engulfed prokaryote?
- To answer this question, you need to understand the evidence supporting the endosymbiont theory. One key piece of evidence is the fact that mitochondria and chloroplasts, which are thought to have originated from prokaryotic cells engulfed by ancestral eukaryotic cells, replicate independently within eukaryotic cells. This is similar to the replication process in prokaryotes. Therefore, the correct answer is "Chloroplasts and mitochondria replicate in a similar manner as some prokaryotes."