Answer the following question given this paragraph: membrane gradients was known, Mitchell proposed that energy captured through the absorption of light (by phototrophs) or the breakdown of molecules into more stable molecules (by various types of chemotrophs) relied on the same basic (homologous) mechanism, namely the generation of H+ gradients across membranes (the plasma membrane in prokaryotes or the internal membranes of mitochondria or chloroplasts (intracellular organelles, derived from bacteria see below) in eukaryotes. What makes us think that these processes might have a similar evolutionary root, that they are homologous? Basically, it is the observation that in both light- and chemical-based processes captured energy is transferred through the movement of electrons through a membrane-embedded "electron transport chain". An electron transport chain involves a series of membrane and associated proteins and a series of reduction-oxidation or redox reactions (see below) during which electrons move from a high energy donor to a lower energy acceptor. Some of the energy difference between the two is used to move H+ ions across a membrane, generating a H+ concentration gradient. Subsequently the thermodynamically favorable movement of H+ down this concentration gradient (across the membrane) is used to drive ATP synthesis, a thermodynamically unfavorable process. ATP synthesis itself involves the rotating ATP synthase. The reaction can be written: H+outside + ADP + Pi ATP + H2O + H+inside, where "inside" and "outside" refer to compartments defined by the membrane containing the electron transport chain and the ATP synthase. Again, this reaction can run backwards. When this occurs, the ATP synthase acts as an ATPase (ATP hydrolase) that can pump H+ (or other molecules) against its concentration gradient. Such pumping ATPases establishes most biologically important molecular gradients across membranes. In such a reaction: ATP + H2O + molecule in low concentration region ADP + Pi + molecule in low concentration region. The most important difference between... Q: What major pigment in the photosynthetic system is based on a complex molecule and gives plants their green color? Choices: - chloroplasm - melanin - cadmium - chlorophyll A:
chlorophyll
(Question)
Answer the following question given this paragraph: A body that is lying down is described as either prone or supine. Prone describes a face-down orientation, and supine describes a face up orientation. These terms are sometimes used in describing the position of the body during specific physical examinations or surgical procedures. Q: What term describes the orientation of a body lying face-down? Choices: - Under - Diagnal - Supine - prone A:
(Answer)
prone
Ques: Answer the following question given this paragraph: Evolution of Gene Regulation Prokaryotic cells can only regulate gene expression by controlling the amount of transcription. As eukaryotic cells evolved, the complexity of the control of gene expression increased. For example, with the evolution of eukaryotic cells came compartmentalization of important cellular components and cellular processes. A nuclear region that contains the DNA was formed. Transcription and translation were physically separated into two different cellular compartments. It therefore became possible to control gene expression by regulating transcription in the nucleus, and also by controlling the RNA levels and protein translation present outside the nucleus. Some cellular processes arose from the need of the organism to defend itself. Cellular processes such as gene silencing developed to protect the cell from viral or parasitic infections. If the cell could quickly shut off gene expression for a short period of time, it would be able to survive an infection when other organisms could not. Therefore, the organism evolved a new process that helped it survive, and it was able to pass this new development to offspring. Q: Prokaryotic cells can only regulate gene expression by controlling the amount of what? Choices: - folding - translation - RNA processing - transcription A:
Ans: transcription
(Q).
Answer the following question given this paragraph: A heat wave over the United States as indicated by heat radiated from the ground. The bright yellow areas are the hottest, and the blue and white are coolest. Q: In a heat map, what color represents the hottest temperatures? Choices: - bright red - orange - pink - bright yellow A:
(A).
bright yellow
Ques:Answer the following question given this paragraph: In conduction, heat is transferred from molecule to molecule by contact. Warmer molecules vibrate faster than cooler ones. They bump into the cooler molecules. When they do they transfer some of their energy. Conduction happens mainly in the lower atmosphere. Can you explain why?. Q: What is the term for heat being transferred from molecule to molecule? Choices: - convection - oxidation - decomposition - conduction A:

Ans:conduction
Answer the following question given this paragraph: Darwin finally published his theory of evolution by natural selection in 1859. He presented it in his book On the Origin of Species . The book is very detailed and includes a lot of evidence for the theory. Darwin's book changed science forever. The theory of evolution by natural selection became the unifying theory of all life science. Q: Which landmark book on evolution via natural selection did charles darwin publish in 1859? Choices: - on the origin of mammals - on the ethnic of species - on various kinds of animals - on the origin of species A:
on the origin of species