[Q]: John was studying about the history of Sahara desert. He was amazed to find that ten thousand years ago there were plenty of rainfall in that region. He labeled that era as era A. Then he found that rainfall deceased in the region about eight thousand years ago. He labeled that era as era B. He was wondering how that change in rainfall might have helped emerge the Egyptian civilization. In which era new surfaces would be exposed, era A or era B? Hint: Rainfall in an area is important because it influences the rate of weathering. More rain means that more rainwater passes through the soil. The rainwater reacts chemically with the particles. The top layers of soil are in contact with the freshest water, so reactions are greatest there. High rainfall increases the amount of rock that experiences chemical reactions. High rainfall may also carry material away. This means that new surfaces are exposed. This increases the rate of weathering.
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[A]: era A

[Q]: John is a doctor at the children's hospital. He had two different cases to investigate, case A and case B. In case case A, a baby continued to suckle mother's milk. But in case B, a baby stopped suckling mother's milk. He had to determine the different effects these two cases were causing. In case B would less or more milk be produced than in case A? Hint: Some processes in the body are regulated by positive feedback. Positive feedback is when a response to an event increases the likelihood of the event to continue. An example of positive feedback is milk production in nursing mothers. As the baby drinks her mother's milk, the hormone prolactin, a chemical signal, is released. The more the baby suckles, the more prolactin is released, which causes more milk to be produced. Other examples of positive feedback include contractions during childbirth. When constrictions in the uterus push a baby into the birth canal, additional contractions occur.
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[A]: less

[Q]: Jeffrey is an avid grower of plants and he currently has some daisies and roses in his bedroom. Jeffrey's friend Robert gives Jeffrey a bottle of gibberellins one day and tells Jeffrey to pour some of the bottle onto the daisies. Jeffrey doesn't question this, because he is very trusting of his friend Robert, and pours the gibberellins onto the daisies, but not onto the roses. Which plants will grow faster, the daisies or the roses? Hint: Gibberellins are hormones that cause the plant to grow. When gibberellins are applied to plants by scientists, the stems grow longer. Some gardeners or horticulture scientists add gibberellins to increase the growth of plants. Dwarf plants (small plants), on the other hand, have low levels of gibberellins ( Figure below ). Another function of gibberellins is to stop dormancy (resting time) of seeds and buds. Gibberellins signal that it's time for a seed to germinate (sprout) or for a bud to open.
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[A]: the daisies

[Q]: Dan found three rattle snakes: one only had one rattle, the second snake had 4 rattles and the third snake had seven rattles on its tail. Which snake had more segments, the first or the third snake Dan found? Hint: At birth, a rattlesnake hatchling has only a small button or 'primordial rattle' which is firmly attached to the tip of the tail.[13] The first segment is added when the hatchling sheds its skin for the first time.[14] A new section is added each time the skin is shed until a rattle is formed. The rattle grows as the snake ages but segments are also prone to breaking off and hence the length of a rattle is not a reliable indicator of the age of a snake.[15]
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[A]:
the third