Answer the following question given this paragraph: Chemical reactions constantly occur inside the cells of living things. However, under the conditions inside cells, most biochemical reactions would occur too slowly to maintain life. That's where enzymes come in. Enzymes are catalysts in living things. Like other catalysts, they speed up chemical reactions. Enzymes are proteins that are synthesized in the cells that need them, based on instructions encoded in the cells' DNA. Q: What proteins synthesized in cells act as catalysts? Choices: - hormones - virophages - byproducts - enzymes A:
enzymes

Answer the following question given this paragraph: During sexual reproduction, two haploid gametes join in the process of fertilization to produce a diploid zygote. Meiosis is the type of cell division that produces gametes. It involves two cell divisions and produces four haploid cells. Q: What is the type of cell division that produces gametes called? Choices: - mitosis - electrolysis - fertilization - meiosis A:
meiosis

Answer the following question given this paragraph: Q: A group of genetically identical individuals is called what? Choices: - brother - replicant - a man - a clone A:
a clone

Answer the following question given this paragraph: From left to right across the periodic table, each element has one more proton than the element to its left. Because atoms are always electrically neutral, for each added proton, one electron is also added. Electrons are added first to the lowest energy level possible until that level is full. Only then are electrons added to the next higher energy level. Q: Because atoms are always electrically neutral, for each added proton, one of what is also added? Choices: - ion - quark - neutron - electron A:
electron