input: OPTIONS:
- they stay the same
- they change randomly
- they get longer
- they get shorter Now, answer this question: Answer the following question given this paragraph: For example, in the fall, when the days start to get shorter, the trees sense that there is less sunlight. The plant is stimulated, and it sends messages telling the leaves to change colors and fall. This is an example of photoperiodism , the reaction of organisms, such as plants, to the length of day or night. Photoperiodism is also the reaction of plants to the length of light and dark periods. Many flowering plants sense the length of night, a dark period, as a signal to flower. Each plant has a different photoperiod, or night length. When the plant senses the appropriate length of darkness, resulting in an appropriate length of daylight, it flowers. Flowering plants are classified as long-day plants or short-day plants. Long-day plants flower when the length of daylight exceeds the necessary photoperiod, and short-day plants flower when the day length is shorter than the necessary photoperiod. Long-day plants include carnations, clover, lettuce, wheat, and turnips. Short-day plants include cotton, rice, and sugar cane. Q: What happens to the length of the days in the fall? A:
A:
output: they get shorter

Answer the following question given this paragraph: Q: How do organophostbate pesticides work? A:

OPTIONS:
- inhibiting reticulum
- inhibiting cryptosporidium
- inhibiting testosterone
- inhibiting acetylcholinesterase

Answer: inhibiting acetylcholinesterase

Problem: OPTIONS:
- electromagnetic dynamics
- energy propagation
- wave dynamics
- wave propagation
Q: Answer the following question given this paragraph: The Dutch scientist Christiaan Huygens (16291695) developed a useful technique for determining in detail how and where waves propagate. Starting from some known position, Huygens's principle states that: Every point on a wavefront is a source of wavelets that spread out in the forward direction at the same speed as the wave itself. The new wavefront is a line tangent to all of the wavelets. Figure 27.5 shows how Huygens's principle is applied. A wavefront is the long edge that moves, for example, the crest or the trough. Each point on the wavefront emits a semicircular wave that moves at the propagation speed v . These are drawn at a time t later, so that they have moved a distance s = vt . The new wavefront is a line tangent to the wavelets and is where we would expect the wave to be a time t later. Huygens's principle works for all types of waves, including water waves, sound waves, and light waves. We will find it useful not only in describing how light waves propagate, but also in explaining the laws of reflection and refraction. In addition, we will see that Huygens's principle tells us how and where light rays interfere. Q: Dutch scientist christiaan huygens' principle of what states that every point on a wavefront is a source of wavelets that spread out in the forward direction at the speed of the wave itself? A:
Answer: wave propagation

Problem:OPTIONS:
- circular
- rectangular
- diamond
- heart-shaped

Answer the following question given this paragraph: In ferns, the sporophyte is dominant and produces spores that germinate into a heart-shaped gametophyte. Q: What shape is the gametophyte in ferns? A:
****
A: heart-shaped

Answer the following question given this paragraph: Remember that individuals do not evolve. Their genes do not change over time. The unit of evolution is the population. A population consists of organisms of the same species that live in the same area. In terms of evolution, the population is assumed to be a relatively closed group. This means that most mating takes place within the population. The science that focuses on evolution within populations is population genetics . It is a combination of evolutionary theory and Mendelian genetics. Q: What is the unit of evolution? A:
OPTIONS:
- species
- community
- biome
- population
population

Answer the following question given this paragraph: Barrier islands provide natural protection to shorelines. Storm waves strike the barrier island before they reach the shore. People also build artificial barriers, called breakwaters . Breakwaters also protect the shoreline from incoming waves. You can see an example of a breakwater in Figure below . It runs parallel to the coast like a barrier island. Q: What kind of islands provide natural protection to shorelines? A:
OPTIONS:
- patch islands
- locational islands
- edge islands
- barrier islands

Answer:
barrier islands