Ques:Answer the following question given this paragraph: Q: What can lead to a loss of genetic variation within populations? Choices: - migration - adaptation - natural selection - genetic drift A:

Ans:genetic drift
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Ques:Answer the following question given this paragraph: The scientists used geologic dating techniques on seafloor rocks. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. The scientists were surprised to find that the oldest seafloor is less than 180 million years old. This may seem old, but the oldest continental crust is around 4 billion years old. Q: Scientists found that the youngest rocks on the seafloor were where? Choices: - trenches. - mid - ocean sediments - mid - ocean glaciers - mid-ocean ridges A:

Ans:mid-ocean ridges
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Ques:Answer the following question given this paragraph: HIV spreads through contact between an infected person's body fluids and another person's bloodstream or mucus membranes, which are found in the mouth, nose, and genital areas. Body fluids that may contain HIV are blood, semen, vaginal fluid, and breast milk. The virus can spread through sexual contact or shared drug needles. It can also spread from an infected mother to her baby during childbirth or breastfeeding. Saliva can carry the HIV virus, but it won't spread it, unless the saliva gets into the bloodstream. Other body fluids such as urine and sweat do not contain the virus. HIV does not spread in any fluid in which the host cells cannot survive. Q: Saliva can carry the hiv virus, but it won't spread it, unless the saliva gets into what? Choices: - lungs - kidneys - liver - bloodstream A:

Ans:bloodstream
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Ques:Answer the following question given this paragraph: Another familiar example is the mixing of vinegar and olive oil. Olive oil is a nonpolar substance, while vinegar (which is mostly water and acetic acid) is polar. The result is a heterogeneous mixture that exhibits a bilayer. Q: Combining nonpolar olive oil and polar vinegar yields what type of mixture? Choices: - homogeneous - omnigeneous - amorphous - heterogeneous A:

Ans:
heterogeneous
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