Answer the following question given this paragraph: Sodium and chloride ions have equal but opposite charges. Opposite electric charges attract each other, so sodium and chloride ions cling together in a strong ionic bond. You can see this in row 2 of the Figure above . (Brackets separate the ions in the diagram to show that the ions in the compound do not actually share electrons. ) When ionic bonds hold ions together, they form an ionic compound. The compound formed from sodium and chloride ions is named sodium chloride. It is commonly called table salt. You can see an animation of sodium chloride forming at this URL: http://www. visionlearning. com/library/module_viewer. php?mid=55. Q: Sodium and chloride ions have equal but what charges? A:
OPTIONS:
- path
- positive
- simple
- opposite
opposite

Answer the following question given this paragraph: Microfilaments , shown as (b) in Figure below , are made of two thin actin chains that are twisted around one another. Microfilaments are mostly concentrated just beneath the cell membrane, where they support the cell and help the cell keep its shape. Microfilaments form cytoplasmatic extentions, such as pseudopodia and microvilli , which allow certain cells to move. The actin of the microfilaments interacts with the protein myosin to cause contraction in muscle cells. Microfilaments are found in almost every cell, and are numerous in muscle cells and in cells that move by changing shape, such as phagocytes (white blood cells that search the body for bacteria and other invaders). Q: Microfilaments are mostly concentrated just beneath what? A:
OPTIONS:
- the nucleus
- the cell wall
- the cytoplasm
- the cell membrane

Answer: the cell membrane

Question: Answer the following question given this paragraph: Destructive interference occurs when the crests of one wave overlap the troughs, or lowest points, of another wave. The Figure below shows what happens. As the waves pass through each other, the crests and troughs cancel each other out to produce a wave with zero amplitude. You can see an animation of destructive interference at this URL: http://phys23p. sl. psu. edu/phys_anim/waves/embederQ1.20200. html. Q: What occurs when the crests of one wave overlap the troughs, or lowest points, of another wave? A:
OPTIONS:
- harmful interference
- random interference
- constructive interference
- destructive interference
Answer: destructive interference

input with options: Answer the following question given this paragraph: Besides entertaining a cat, laser light has many other uses. One use is carrying communication signals in optical fibers. Sounds or pictures are encoded in pulses of laser light, which are then sent through an optical fiber. All of the light reflects off the inside of the fiber, so none of it escapes. As a result, the signal remains strong even over long distances. More than one signal can travel through an optical fiber at the same time, as you can see in the Figure below . Optical fibers are used to carry telephone, cable TV, and Internet signals. Q: Sounds or pictures can be encoded in pulses of what, which are then sent through an optical fiber? A:
OPTIONS:
- kinetic energy
- microwaves
- quasars
- laser light
output: laser light

Q: Answer the following question given this paragraph: Amphibians have permeable skin that easily absorbs substances from the environment. This may explain why they seem to be especially sensitive to pollution. Monitoring the health and survival of amphibians may help people detect pollution early, before other organisms are affected. Q: What group of animals has permeable skin that makes them vulnerable to pollution? A:

OPTIONS:
- fish
- mammals
- reptiles
- amphibians

A: amphibians

Answer the following question given this paragraph: Q: What holds homologs together as the spindle forms for the first meiotic division? A:
OPTIONS:
- magnetism
- pollenation
- spirogyra
- chiasmata
chiasmata