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:
uterus
(Question)
Answer the following question given this paragraph: Q: Via what process do substance move from one cell to another? Choices: - reverse transferase - autolysis - downregulation - plasmodesmata A:
(Answer)
plasmodesmata
Ques: Answer the following question given this paragraph: Antibodies also mark pathogens for destruction by phagocytic cells, such as macrophages or neutrophils, because phagocytic cells are highly attracted to macromolecules complexed with antibodies. Phagocytic enhancement by antibodies is called opsonization. In a process called complement fixation, IgM and IgG in serum bind to antigens and provide docking sites onto which sequential complement proteins can bind. The combination of antibodies and complement enhances opsonization even further and promotes rapid clearing of pathogens. Affinity, Avidity, and Cross Reactivity Not all antibodies bind with the same strength, specificity, and stability. In fact, antibodies exhibit different affinities (attraction) depending on the molecular complementarity between antigen and antibody molecules, as illustrated in Figure 42.25. An antibody with a higher affinity for a particular antigen would bind more strongly and stably, and thus would be expected to present a more challenging defense against the pathogen corresponding to the specific antigen. Q: Antibodies also mark pathogens for destruction by which cells? Choices: - interferons - leukocytes - platelets - phagocytic A:
Ans: phagocytic
(Q).
Answer the following question given this paragraph: From a human point of view, natural resources can be classified as either renewable or nonrenewable. Q: How can natural resources be classified from a human point of view? Choices: - renewable or reversible - recyclable or reusable - present or nonrenewable - renewable or nonrenewable A:
(A).
renewable or nonrenewable
Ques:Answer the following question given this paragraph: Most digestive enzymes are secreted into the GI tract by organs of the GI tract or from a nearby gland named the pancreas. Figure below shows where the pancreas is located. The figure also shows the locations of the liver and gall bladder. These organs produce or store other digestive secretions. Q: What are secreted into the gi tract by organs of the gi tract or from a nearby gland named the pancreas? Choices: - stomach acid - insulin and pepsin - bile - digestive enzymes A:

Ans:digestive enzymes
Ques: Answer the following question given this paragraph: An electric circuit consists of at least one closed loop through which electric current can flow. Every circuit has a voltage source such as a battery and a conductor such as metal wire. A circuit may have other parts as well, such as lights and switches. In addition, a circuit may consist of one loop or two loops. Q: What is the minimum number of loops a circuit can have? Choices: - 3 - .1 - 2 - 1 A:
Ans:
1