(Question)
Answer the following question given this paragraph: The atomic weight of an element is a weighted average of its isotopes. Q: How do you determine the atomic weight of an element? Choices: - multiply protons and neutrons - subtract protons from electrons - divide protons and neutrons - add up protons and neutrons A:
(Answer)
add up protons and neutrons

(Question)
Answer the following question given this paragraph: So far we have focused on traits due to one gene or several genes. But what about many genes? 100s or 1000s of genes? What would happen if an entire chromosome were missing or duplicated? What if a human had only 45 chromosomes? Or 47? This real possibility is usually due to mistakes during meiosis; the chromosomes do not fully separate from each other during sperm or egg formation. Specifically, nondisjunction is the failure of replicated chromosomes to separate during anaphase II. If a zygote forms from a gamete lacking a chromosome, a viable embryo cannot be produced. Most human abnormal chromosome numbers result in the death of the developing embryo, often before a woman even realizes she is pregnant. Occasionally, a zygote with an extra chromosome can become a viable embryo and develop. Q: If a human only has 45 chromosomes it is most likely due to a mistake during what? Choices: - testis - mitosis - plexus - meiosis A:
(Answer)
meiosis

(Question)
Answer the following question given this paragraph: Paleontology, another branch of biology, uses fossils to study life's history (Figure 1.20). Zoology and botany are the study of animals and plants, respectively. Biologists can also specialize as biotechnologists, ecologists, or physiologists, to name just a few areas. This is just a small sample of the many fields that biologists can pursue. Biology is the culmination of the achievements of the natural sciences from their inception to today. Excitingly, it is the cradle of emerging sciences, such as the biology of brain activity, genetic engineering of custom organisms, and the biology of evolution that uses the laboratory tools of molecular biology to retrace the earliest stages of life on earth. A scan of news headlineswhether reporting on immunizations, a newly discovered species, sports doping, or a genetically-modified fooddemonstrates the way biology is active in and important to our everyday world. Q: What branch of biology uses fossils to study life's history? Choices: - morphology - entomology - gerontology - paleontology A:
(Answer)
paleontology