Answer the following question given this paragraph:   Contact Between Sperm and Oocyte Upon ovulation, the oocyte released by the ovary is swept into—and along—the uterine tube. Fertilization must occur in the distal uterine tube because an unfertilized oocyte cannot survive the 72-hour journey to the uterus. As you will recall from your study of the oogenesis, this oocyte (specifically a secondary oocyte) is surrounded by two protective layers. The corona radiata is an outer layer of follicular (granulosa) cells that form around a developing oocyte in the ovary and remain with it upon ovulation. The underlying zona pellucida (pellucid = “transparent”) is a transparent, but thick, glycoprotein membrane that surrounds the cell’s plasma membrane. As it is swept along the distal uterine tube, the oocyte encounters the surviving capacitated sperm, which stream toward it in response to chemical attractants released by the cells of the corona radiata. To reach the oocyte itself, the sperm must penetrate the two protective layers. The sperm first burrow through the cells of the corona radiata. Then, upon contact with the zona pellucida, the sperm bind to receptors in the zona pellucida. This initiates a process called the acrosomal reaction in which the enzyme-filled “cap” of the sperm, called the acrosome, releases its stored digestive enzymes. These enzymes clear a path through the zona pellucida that allows sperm to reach the oocyte. Finally, a single sperm makes contact with sperm-binding receptors on the oocyte’s plasma membrane (Figure 28.2). The plasma membrane of that sperm then fuses with the oocyte’s plasma membrane, and the head and mid-piece of the “winning” sperm enter the oocyte interior. How do sperm penetrate the corona radiata? Some sperm undergo a spontaneous acrosomal reaction, which is an acrosomal reaction not triggered by contact with the zona pellucida. The digestive enzymes released by this reaction digest the extracellular matrix of the corona radiata. As you can see, the first sperm to reach the oocyte is never the one to fertilize it. Rather,...   Q: Upon ovulation, the oocyte released by the ovary is swept into where?   A:

Answer: uterine tube


Answer the following question given this paragraph:   Scientists also collect rock and sediment samples from the seafloor. A dredge is a giant rectangular bucket that is dragged along behind a ship. The dredge picks up loose rocks lying on the seafloor. Gravity corers are metal tubes that fall to the seafloor. They slice into the sediments to collect a sample. The research vessel, the Joides Resolution , drills deep into the seafloor to collect samples of the sediment and ocean crust. Scientists analyze the samples for chemistry and their magnetic properties.   Q: Behind a ship, what is the giant rectangular bucket that is dragged along from the behind called?   A:

Answer: dredge


Answer the following question given this paragraph:   Interspecific competition occurs between members of different species. It may lead to one species going extinct or both becoming more specialized.   Q: Which competition leads to one species going extinct or both becoming more specialized?   A:

Answer:
interspecific