Answer the following question given this paragraph: Viruses are so small that they can be seen only with an electron microscope. Before electron microscopes were invented, scientists knew viruses must exist. How did they know? They had demonstrated that particles smaller than bacteria cause disease. Q: They had demonstrated that particles smaller than bacteria cause what? Choices: - blood - flight - damage - disease A:
disease
Answer the following question given this paragraph: The gene theory is the idea that the characteristics of living organisms are controlled by genes, which are passed from parents to their offspring. A gene is a segment of DNA that has the instructions to encode a protein. Genes are located on larger structures, called chromosomes , that are found inside every cell. Chromosomes, in turn, contain large molecules known as DNA (deoxyribonucleic acid). Molecules of DNA are encoded with instructions that tell cells what to do. To see how this happens, click on the animation titled Journey into DNA at the following link: http://www. pbs. org/wgbh/nova/genome/dna. html . Q: Which theory is the idea that the characteristics of living organisms are controlled by genes, which are passed from parents to their offspring? Choices: - species theory - evolution theory - fossil theory - gene theory A:
gene theory
Q: Answer the following question given this paragraph: Enzyme Compartmentalization In eukaryotic cells, molecules such as enzymes are usually compartmentalized into different organelles. This allows for yet another level of regulation of enzyme activity. Enzymes required only for certain cellular processes can be housed separately along with their substrates, allowing for more efficient chemical reactions. Examples of this sort of enzyme regulation based on location and proximity include the enzymes involved in the latter stages of cellular respiration, which take place exclusively in the mitochondria, and the enzymes involved in the digestion of cellular debris and foreign materials, located within lysosomes. Feedback Inhibition in Metabolic Pathways Molecules can regulate enzyme function in many ways. A major question remains, however: What are these molecules and where do they come from? Some are cofactors and coenzymes, ions, and organic molecules, as you've learned. What other molecules in the cell provide enzymatic regulation, such as allosteric modulation, and competitive and noncompetitive inhibition? The answer is that a wide variety of molecules can perform these roles. Some of these molecules include pharmaceutical and non-pharmaceutical drugs, toxins, and poisons from the environment. Perhaps the most relevant sources of enzyme regulatory molecules, with respect to cellular metabolism, are the products of the cellular metabolic reactions themselves. In a most efficient and elegant way, cells have evolved to use the products of their own reactions for feedback inhibition of enzyme activity. Feedback inhibition involves the use of a reaction product to regulate its own further production (Figure 6.21). The cell responds to the abundance of specific products by slowing down production during anabolic or catabolic reactions. Such reaction products may inhibit the enzymes that catalyzed their production through the mechanisms described above. Q: In eukaryotic cells, molecules such as enzymes are usually compartmentalized into different what? Choices: - organisms - atoms - electrons - organelles A:
A: organelles
Question: Answer the following question given this paragraph: Matter can be classified on the basis of how light interacts with it. Matter may be transparent, translucent, or opaque. Each type of matter is illustrated in Figure below . Q: Matter can be classified on the basis of how what interacts with it? Choices: - air - gravity - water - light A:
Answer: light
*Question*
Answer the following question given this paragraph: Development of the Embryo In the vast majority of ectopic pregnancies, the embryo does not complete its journey to the uterus and implants in the uterine tube, referred to as a tubal pregnancy. However, there are also ovarian ectopic pregnancies (in which the egg never left the ovary) and abdominal ectopic pregnancies (in which an egg was "lost" to the abdominal cavity during the transfer from ovary to uterine tube, or in which an embryo from a tubal pregnancy re-implanted in the abdomen). Once in the abdominal cavity, an embryo can implant into any well-vascularized structurethe rectouterine cavity (Douglas' pouch), the mesentery of the intestines, and the greater omentum are some common sites. Tubal pregnancies can be caused by scar tissue within the tube following a sexually transmitted bacterial infection. The scar tissue impedes the progress of the embryo into the uterusin some cases "snagging" the embryo and, in other cases, blocking the tube completely. Approximately one half of tubal pregnancies resolve spontaneously. Implantation in a uterine tube causes bleeding, which appears to stimulate smooth muscle contractions and expulsion of the embryo. In the remaining cases, medical or surgical intervention is necessary. If an ectopic pregnancy is detected early, the embryo's development can be arrested by the administration of the cytotoxic drug methotrexate, which inhibits the metabolism of folic acid. If diagnosis is late and the uterine tube is already ruptured, surgical repair is essential. Even if the embryo has successfully found its way to the uterus, it does not always implant in an optimal location (the fundus or the posterior wall of the uterus). Placenta previa can result if an embryo implants close to the internal os of the uterus (the internal opening of the cervix). As the fetus grows, the placenta can partially or completely cover the opening of the cervix (Figure 28.7). Although it occurs in only 0.5 percent of pregnancies, placenta previa is the leading cause of antepartum hemorrhage... Q: In the vast majority of ectopic pregnancies, the embryo does not complete its journey to what organ, and instead implants in the uterine tube? Choices: - stomach - ovaries - vagina - uterus A:
**Answer**
uterus
(Question)
Answer the following question given this paragraph: Acne Acne is a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (face and back). It is most common along with the onset of puberty due to associated hormonal changes, but can also occur in infants and continue into adulthood. Hormones, such as androgens, stimulate the release of sebum. An overproduction and accumulation of sebum along with keratin can block hair follicles. This plug is initially white. The sebum, when oxidized by exposure to air, turns black. Acne results from infection by acne-causing bacteria (Propionibacterium and Staphylococcus), which can lead to redness and potential scarring due to the natural wound healing process (Figure 5.22). Q: Acne is a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (face and back). it is most common along with the onset of puberty due to association with these? Choices: - mental changes - digestive changes - thermal changes - hormonal changes A:
(Answer)
hormonal changes