Q: The creation and destruction of oceanic crust is the reason what moves? Read this paragraph and choose the correct option from the provided answers: In some places, the oceanic crust comes up to a continent. The moving crust pushes that continent away from the ridge axis as well. If the moving oceanic crust reaches a deep sea trench, the crust sinks into the mantle. The creation and destruction of oceanic crust is the reason that continents move. Choices: - animals - planets - oceans - continents A:
continents
------
Q: Loss of energy is the reason that what typically has few levels? Read this paragraph and choose the correct option from the provided answers: At each level of a food chain, a lot of energy is lost. Only about ten percent of the energy passes to the next level. Where does that energy go? Some energy is given off as heat. Some energy goes into animal wastes. Energy also goes into growing things that another consumer can't eat, like fur. It's because so much energy is lost that most food chains have just a few levels. There's not enough energy left for higher levels. Choices: - humans - the atmosphere - video games - food chain A:
food chain
------
Q: What is the net force when two forces act in the same direction? Read this paragraph and choose the correct option from the provided answers: Two forces may act on an object in the same direction. You can see an example of this in Figure below . After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. Choices: - number of the forces - arguing forces - group of forces - sum of the forces A:
sum of the forces
------
Q: What substances that primarily comprise plasma membranes form a bilayer? Read this paragraph and choose the correct option from the provided answers: Plasma membranes are primarily made up of phospholipids (orange). The hydrophilic ("water-loving") head and two hydrophobic ("water-hating") tails are shown. The phospholipids form a bilayer (two layers). The middle of the bilayer is an area without water. There can be water on either side of the bilayer. There are many proteins throughout the membrane. Choices: - amino acids - enzymes - steroids - phospholipids A:
phospholipids
------