Answer the following question given this paragraph: Anaphase is the phase in which the sister chromatids separate. The sister chromatids are pulled apart by the shortening of the microtubules of the spindles, similar to the reeling in of a fish by the shortening of the fishing line. One sister chromatid moves to one pole of the cell, and the other sister chromatid moves to the opposite pole. This process occurs when the proteins that bind sister chromatids together are cleaved, resulting in unattached identical chromosomes, essentially separate daughter chromosomes. These separate chromosomes are pulled apart by shortening spindle fibers, and pulled toward the centrosomes to which they are attached. At the end of anaphase the spindle fibers degrade. At this time, each pole of the cell has a complete set of chromosomes, identical to the amount of DNA at the beginning of G 1 of the cell cycle. Q: In which phase do the sister chromatids separate? Choices: - prophase - passivation - latent phase - anaphase A:
anaphase
(Question)
Answer the following question given this paragraph: Each step of the food chain in the energy pyramid is called a trophic level . Plants or other photosynthetic organisms ( autotrophs ) are found on the first trophic level, at the bottom of the pyramid. The next level will be the herbivores, and then the carnivores that eat the herbivores. The energy pyramid ( Figure below ) shows four levels of a food chain, from producers to carnivores. Because of the high rate of energy loss in food chains, there are usually only 4 or 5 trophic levels in the food chain or energy pyramid. There just is not enough energy to support any additional trophic levels. Heterotrophs are found in all levels of an energy pyramid other than the first level. Q: What organism is at the top of the energy pyramid? Choices: - primate - herbivore - insects - carnivore A:
(Answer)
carnivore
Ques: Answer the following question given this paragraph: Pluto and its moon, Charon, are actually two objects. Q: What is the name of pluto's moon? Choices: - Phobos - Titania - Europa - charon A:
Ans: charon
(Q).
Answer the following question given this paragraph: The process that produces haploid gametes is meiosis. Meiosis is a type of cell division in which the number of chromosomes is reduced by half. It occurs only in certain special cells of the organisms. During meiosis, homologous chromosomes separate, and haploid cells form that have only one chromosome from each pair. Two cell divisions occur during meiosis, and a total of four haploid cells are produced. The two cell divisions are called meiosis I and meiosis II. The overall process of meiosis is summarized in Figure below . You can watch an animation of meiosis at this link: http://www. youtube. com/watch?v=D1_-mQS_FZ0 . Q: What is the type of cell division where the number of chromosomes is reduced in half? Choices: - cloning - mitosis - interphase - meiosis A:
(A).
meiosis
Ques:Answer the following question given this paragraph: Because the hydroxyl radical has an unpaired electron, it is highly reactive. (This is true of any substance with unpaired electrons, known as a free radical. ) This hydroxyl radical can react with all kinds of biological molecules (DNA, proteins, enzymes, and so on), causing damage to the molecules and disrupting physiological processes. Examples of direct and indirect damage are shown in Figure 21.32. Q: The hydroxyl radical is highly reactive because it has what? Choices: - unpaired neutron - paired proton - paired electron - unpaired electron A:

Ans:unpaired electron
Question: Answer the following question given this paragraph: Nuclear fission is the splitting of the nucleus of an atom into two smaller nuclei. This type of reaction releases a great deal of energy from a very small amount of matter. For example, nuclear fission of a tiny pellet of uranium-235, like the one pictured in Figure below , can release as much energy as burning 1,000 kilograms of coal!. Q: What do you call the splitting of the nucleus of an atom into two smaller nuclei? Choices: - critical fission - nuclear fusion - cell division - nuclear fission A:
Answer:
nuclear fission