Answer the following question given this paragraph: Q: Who controls prey population? Choices: - ecosystems - bees - parasites - predators A:
predators
Answer the following question given this paragraph: Members of the genus Trypanosoma are flagellate protozoa that cause sleeping sickness , which is common in Africa. They also cause Chagas disease , which is common in South America. The parasites are spread by insect vectors. The vector for Chagas disease is shown in Figure below . Trypanosoma parasites enter a person's blood when the vector bites. Then they spread to other tissues and organs. The diseases may be fatal without medical treatment. Q: Members of the genus trypanosoma are flagellate protozoa that cause what? Choices: - cancer - hypertension - mutations - sleeping sickness A:
sleeping sickness
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? Choices: - signaler stem cell - omnipoten stem cell - schwann stem cell - totipotent stem cell A:
A: totipotent stem cell
Question: Answer the following question given this paragraph: The esophagus is a narrow tube that carries food from the throat to the stomach. Food moves through the esophagus because of peristalsis. At the lower end of the esophagus, a circular muscle controls the opening to the stomach. The muscle relaxes to let food pass into the stomach. Then the muscle contracts again to prevent food from passing back into the esophagus. Q: What causes food to move through the esophagus? Choices: - photosynthesis - proteolysis - apoptosis - peristalsis A:
Answer: peristalsis
*Question*
Answer the following question given this paragraph: The ocean floor is home to many species of living things. Some from shallow water are used by people for food. Clams and some fish are among the many foods we get from the ocean floor. Some living things on the ocean floor are sources of human medicines. For example, certain bacteria on the ocean floor produce chemicals that fight cancer. Q: Some living things on the ocean floor are sources of what human necessity? Choices: - hormones - steroids - pesticides - medicines A:
**Answer**
medicines
*Question*
Answer the following question given this paragraph: What is a cell? Gradient Physical difference between two regions of space, in such a way that the molecules tend to move in response to the gradients. Diffusion Movement of the molecules in a fluid, from the regions of high concentration to those of low concentration. Passive transport Movement of substances in a membrane that doesn't need to use energy. Simple diffusion Diffusion of water, gases or molecules across the membrane. Facilitated diffusion Diffusion of molecules across the membranes with the participation of proteins. Osmosis Diffusion of the water across a membrane with differential permeability. Transport that needs energy Movement of substances across a membrane generally in opposition to a gradient of concentration with the requirement of energy. Active transport Movement of small molecules using energy (ATP). Endocytosis Movement of big particles towards the interior of the cell using energy. The cells enclose particles or liquids. Pinocytosis (Literally cell drinking) Form in which the cell introduces liquids. Phagocytosis Way of eating of the cells. It feeds in this case of big particles or entire microorganisms. Pseudopods False feet (the amoeba). Exocitosis Movement of materials out of the cell with the use of energy. It throws waste material. Isotonic The cytoplasm fluid of the interior of the cells is the same that the outer. Hypertonic solution. Q: Pseudopods are false what? Choices: - eyes - teeth - fingers - feet A:
**Answer**
feet