Q: Light reactions occur during which stage of photosynthesis? Read this paragraph and choose the correct option from the provided answers: The light reactions occur in the first stage of photosynthesis. This stage takes place in the thylakoid membranes of the chloroplast. In the light reactions, energy from sunlight is absorbed by chlorophyll. This energy is temporarily transferred to two molecules: ATP and NADPH. These molecules are used to store the energy for the second stage of photosynthesis. The light reactions use water and produce oxygen. Choices: - intermediate stage - third stage - final stage - first stage A:
first stage
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Q: Many countries have attempted to reduce the human impact on climate change by reducing their emission of what greenhouse gas? Read this paragraph and choose the correct option from the provided answers: Efforts to control population growth led to the one-child policy in China, which used to include more severe consequences, but now imposes fines on urban couples who have more than one child. Due to the fact that some couples wish to have a male heir, many Chinese couples continue to have more than one child. The policy itself, its social impacts, and the effectiveness of limiting overall population growth are controversial. In spite of population control policies, the human population continues to grow. At some point the food supply may run out because of the subsequent need to produce more and more food to feed our population. The United Nations estimates that future world population growth may vary from 6 billion (a decrease) to 16 billion people by the year 2100. There is no way to know whether human population growth will moderate to the point where the crisis described by Dr. Ehrlich will be averted. Another result of population growth is the endangerment of the natural environment. Many countries have attempted to reduce the human impact on climate change by reducing their emission of the greenhouse gas carbon dioxide. However, these treaties have not been ratified by every country, and many underdeveloped countries trying to improve their economic condition may be less likely to agree with such provisions if it means slower economic development. Furthermore, the role of human activity in causing climate change has become a hotly debated socio-political issue in some developed countries, including the United States. Thus, we enter the future with considerable uncertainty about our ability to curb human population growth and protect our environment. Choices: - methane - acid dioxide - nitrous oxide - carbon dioxide A:
carbon dioxide
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Q: What is glucose used for the bacteria? Read this paragraph and choose the correct option from the provided answers: Photosynthetic bacteria use the energy of the sun to make their own food. In the presence of sunlight, carbon dioxide and water are turned into glucose and oxygen. The glucose is then turned into usable energy. Glucose is like the "food" for the bacteria. An example of photosynthetic bacteria is cyanobacteria, as seen in the opening image. Choices: - reproduction - fuel - energy - food A:
food
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Q: What are the two types of photoreceptors in the retina? Read this paragraph and choose the correct option from the provided answers: Which of the following statements about the human eye is false? a. Rods detect color, while cones detect only shades of gray. When light enters the retina, it passes the ganglion cells and bipolar cells before reaching photoreceptors at the rear of the eye. The iris adjusts the amount of light coming into the eye. The cornea is a protective layer on the front of the eye. The main function of the lens is to focus light on the retina and fovea centralis. The lens is dynamic, focusing and refocusing light as the eye rests on near and far objects in the visual field. The lens is operated by muscles that stretch it flat or allow it to thicken, changing the focal length of light coming through it to focus it sharply on the retina. With age comes the loss of the flexibility of the lens, and a form of farsightedness called presbyopia results. Presbyopia occurs because the image focuses behind the retina. Presbyopia is a deficit similar to a different type of farsightedness called hyperopia caused by an eyeball that is too short. For both defects, images in the distance are clear but images nearby are blurry. Myopia (nearsightedness) occurs when an eyeball is elongated and the image focus falls in front of the retina. In this case, images in the distance are blurry but images nearby are clear. There are two types of photoreceptors in the retina: rods and cones, named for their general appearance as illustrated in Figure 36.18. Rods are strongly photosensitive and are located in the outer edges of the retina. They detect dim light and are used primarily for peripheral and nighttime vision. Cones are weakly photosensitive and are located near the center of the retina. They respond to bright light, and their primary role is in daytime, color vision. Choices: - holes and cones - circles and cones - images and cones - rods and cones A:
rods and cones
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