Answer the following question given this paragraph: The generation of an isolated but open system, which we might call a protocell, was a critical step in the origin of life. Such an isolated system has important properties that are likely to have facilitated the further development of life. For example, because of the membrane boundary, changes that occur within one such structure will not be shared with neighboring systems. Rather, they accumulated in, and favor the survival of, one system over its neighbors. Such systems can also reproduce in a crude way by fragmentation. If changes within one such system improved its stability, its ability to accumulate resources, or its ability to survive and reproduce, that system, and its progeny, would be likely to become more common. As these changes accumulate and are passed from parent to offspring, the organisms will inevitably evolve, as we will see in detail in the next chapter. As in living systems today, the earliest steps in the formation of the first organisms required a source of energy to maintain the non-equilibrium living system. There are really two choices for the source of this energy, either light (electromagnetic radiation from the sun) or thermodynamically unstable chemicals present in the environment. There have been a number of plausible scenarios, based on various observations, for the steps leading to life. For example, a recent study based on the analysis of the genes (and the proteins that they encode) found in modern organisms, suggests that the last universal common ancestor (LUCA) arose in association with hydrothermal vents.60 But whether this reflects LUCA or an ancestor of LUCA that became adapted to living is association with hydrothermal vents is difficult (and perhaps impossible) to resolve unambiguously, particularly since LUCA lived ~3.4-3.8 billion years ago and cannot be studied directly. Mapping the history of life on earth Assuming, as seems likely, that life arose spontaneously, we can now look at what we know about the fossil record to better understand the diversification of... Q: What is the theoretical event that began the universe often called? Choices: - Coreolis effect - dark matter - string theory - big bang A:
big bang
Answer the following question given this paragraph: Describe hurricane formation and the damage they cause. Q: Yogurt is made with milk fermented with what? Choices: - viruses - pathogens - disease - bacteria A:
bacteria
Q: Answer the following question given this paragraph: A : A theory is needed to explain gravity. In science, a theory is a broad explanation that is supported by a great deal of evidence. Q: What is another name for a broad explanation that is supported by a great deal of evidence? Choices: - hypothesis - concept - conjecture - theory A:
A: theory
Question: Answer the following question given this paragraph: Q: The maturing follicle, containing a fluid-filled cavity, enlarges, forming a bulge near the surface of what? Choices: - the pelvis - the abdomen - the vagina - the ovary A:
Answer: the ovary
*Question*
Answer the following question given this paragraph: Figure 2.22 When carbon forms single bonds with other atoms, the shape is tetrahedral. When two carbon atoms form a double bond, the shape is planar, or flat. Single bonds, like those found in ethane, are able to rotate. Double bonds, like those found in ethene cannot rotate, so the atoms on either side are locked in place. Q: When what common element forms single bonds with other atoms, the shape is tetrahedral, and when its atoms form a double bond, the shape is planar? Choices: - oxygen - hydrogen - silicon - carbon A:
**Answer**
carbon
*Question*
Answer the following question given this paragraph: A completely bonding molecular orbital contains no nodes (regions of zero electron probability) perpendicular to the internuclear axis, whereas a completelyantibonding molecular orbital contains at least one node perpendicular to the internuclear axis. A sigma () orbital (bonding) or a sigma star (*) orbital(antibonding) is symmetrical about the internuclear axis. Hence all cross-sections perpendicular to that axis are circular. Both a pi () orbital (bonding) and a pi star (*) orbital (antibonding) possess a nodal plane that contains the nuclei, with electron density localized on both sides of the plane. The energies of the molecular orbitals versus those of the parent atomic orbitals can be shown schematically in an energy-level diagram. The electron configuration of a molecule is shown by placing the correct number of electrons in the appropriate energy-level diagram, starting with the lowest-energy orbital and obeying the Pauli principle; that is, placing only two electrons with opposite spin in each orbital. From the completed energy-level diagram, we can calculate thebond order, defined as one-half the net number of bonding electrons. In bond orders, electrons in antibonding molecular orbitals cancel electrons in bonding molecular orbitals, while electrons in nonbonding orbitals have no effect and are not counted. Bond orders of 1, 2, and 3 correspond to single, double, and triple bonds, respectively. Molecules with predicted bond orders of 0 are generally less stable than the isolated atoms and do not normally exist. Molecular orbital energy-level diagrams for diatomic molecules can be created if the electron configuration of the parent atoms is known, following a few simple rules. Most important, the number of molecular orbitals in a molecule is the same as the number of atomic orbitals that interact. The difference between bonding and antibonding molecular orbital combinations is proportional to the overlap of the parent orbitals and decreases as the energy difference between the parent atomic... Q: Atomic orbitals are populated with what subatomic particles? Choices: - protons - neurons - atoms - electrons A:
**Answer**
electrons