Problem:OPTIONS:
- ancestors
- skeletons
- blood
- excretions

Answer the following question given this paragraph: The Phosphorus Cycle Phosphorus is an essential nutrient for living processes; it is a major component of nucleic acids and phospholipids, and, as calcium phosphate, makes up the supportive components of our bones. Phosphorus is often the limiting nutrient (necessary for growth) in aquatic, particularly freshwater, ecosystems. Phosphorus occurs in nature as the phosphate ion (PO43-). In addition to phosphate runoff as a result of human activity, natural surface runoff occurs when it is leached from phosphate-containing rock by weathering, thus sending phosphates into rivers, lakes, and the ocean. This rock has its origins in the ocean. Phosphate-containing ocean sediments form primarily from the bodies of ocean organisms and from their excretions. However, volcanic ash, aerosols, and mineral dust may also be significant phosphate sources. This sediment then is moved to land over geologic time by the uplifting of Earth's surface. (Figure 20.13) Phosphorus is also reciprocally exchanged between phosphate dissolved in the ocean and marine organisms. The movement of phosphate from the ocean to the land and through the soil is extremely slow, with the average phosphate ion having an oceanic residence time between 20,000 and 100,000 years. Q: Phosphate-containing ocean sediments form primarily from the bodies of ocean organisms and from their what? A:
****
A: excretions

Answer the following question given this paragraph: Q: The db gene encodes the which receptor? A:
OPTIONS:
- glucose
- opioid
- estrogen
- leptin
leptin

Answer the following question given this paragraph: With fossil fuels becoming more expensive and less available, scientists are looking for other energy sources. Hydrogen has long been considered an ideal source, since it does not pollute when it burns. The problem has been finding ways to generate hydrogen economically. One new approach that is being studied is photoelectrolysis the generation of electricity using photovoltaic cells to split water molecules. This technique is still in the research stage, but appears to be a very promising source of power in the future. Q: What is the generation of electricity using photovoltaic cells to split water molecules called? A:
OPTIONS:
- hybrid electricity
- aqua-electricity
- photovoltaic cells
- photoelectrolysis

Answer: photoelectrolysis

Question: Answer the following question given this paragraph: In glycolysis, glucose is split into two molecules of pyruvate. This results in a net gain of two ATP molecules. Q: In glycolysis, glucose is split into two molecules of pyruvate. this results in a net gain of? A:
OPTIONS:
- four atp molecules
- six atp molecules
- three atp molecules
- two atp molecules
Answer: two atp molecules

input with options: Answer the following question given this paragraph: Q: What type of cells are arranged into tightly packed sheaths around the veins of the leaf? A:
OPTIONS:
- pattern - sheath cells
- cellulose
- cell walls
- bundle-sheath cells
output: bundle-sheath cells

Problem: OPTIONS:
- signaler stem cell
- omnipoten stem cell
- schwann stem cell
- totipotent stem cell
Q: Answer the following question given this paragraph: ability to diversify at each step. The totipotent stem cell is the zygote, or fertilized egg. The totipotent (toti- = "all") stem cell gives rise to all cells of the human body. The next level is the pluripotent stem cell, which gives rise to multiple types of cells of the body and some of the supporting fetal membranes. Beneath this level, the mesenchymal cell is a stem cell that develops only into types of connective tissue, including fibrous connective tissue, bone, cartilage, and blood, but not epithelium, muscle, and nervous tissue. One step lower on the hierarchy of stem cells is the hemopoietic stem cell, or hemocytoblast. All of the formed elements of blood originate from this specific type of cell. Hemopoiesis begins when the hemopoietic stem cell is exposed to appropriate chemical stimuli collectively called hemopoietic growth factors, which prompt it to divide and differentiate. One daughter cell remains a hemopoietic stem cell, allowing hemopoiesis to continue. The other daughter cell becomes either of two types of more specialized stem cells (Figure 18.4): Lymphoid stem cells give rise to a class of leukocytes known as lymphocytes, which include the various T cells, B cells, and natural killer (NK) cells, all of which function in immunity. However, hemopoiesis of lymphocytes progresses somewhat differently from the process for the other formed elements. In brief, lymphoid stem cells quickly migrate from the bone marrow to lymphatic tissues, including the lymph nodes, spleen, and thymus, where their production and differentiation continues. B cells are so named since they mature in the bone marrow, while T cells mature in the thymus. Myeloid stem cells give rise to all the other formed elements, including the erythrocytes; megakaryocytes that produce platelets; and a myeloblast lineage that gives rise to monocytes and three forms of granular leukocytes: neutrophils, eosinophils, and basophils. Q: Which cell gives rise to all cells of the human body? A:
Answer:
totipotent stem cell