Answer the following question given this paragraph: The placenta is a temporary organ that begins to form from the trophoblast layer of cells shortly after implantation. (For an animation showing how the placenta forms, go to link below. ) The placenta continues to develop and grow to meet the needs of the growing fetus. A fully developed placenta, like the one in Figure above , is made up of a large mass of blood vessels from both the mother and fetus. The maternal and fetal vessels are close together but separated by tiny spaces. This allows the mother's and fetus's blood to exchange substances across their capillary walls without the blood actually mixing. Q: What is the name of the temporary organ that begins to form from the trophoblast layer of cells shortly after implantation? Choices: - uterus - embryo - appendix - placenta A:
placenta

Answer the following question given this paragraph: Lumbar Vertebrae Lumbar vertebrae carry the greatest amount of body weight and are thus characterized by the large size and thickness of the vertebral body (Figure 7.28). They have short transverse processes and a short, blunt spinous process that projects posteriorly. The articular processes are large, with the superior process facing backward and the inferior facing forward. Q: Which vertebrae carry the greatest amount of body weight and are thus characterized by the large size and thickness of the vertebral body? Choices: - artery vertebrae - invertebrae - thickness vertebrae - lumbar vertebrae A:
lumbar vertebrae

Answer the following question given this paragraph: Observations can happen on many scales. You can use a microscope to observe tiny things. You can use a telescope to observe distant things in space. To learn about the effects of climate change, you could observe Earth's surface. How would you make observations of Earth's surface? You could do this from the land surface or from space. Many important observations are made by orbiting satellites. These satellites have a bird's eye view of how the planet is changing ( Figure below ). Q: What man-made devices in space are used to observe the earth's surface? Choices: - crystals - telescopes - sensors - satellites A:
satellites

Answer the following question given this paragraph: An electron is accelerated from rest through a potential difference of volts. It then enters a region traveling perpendicular to a magnetic field of . Calculate the velocity of the electron. Q: An electron is accelerated from rest through a potential difference of what? Choices: - joules - watts - amperes - volts A:
volts