Answer the following question given this paragraph: Errors during DNA replication are not the only reason why mutations arise in DNA. Mutations, variations in the nucleotide sequence of a genome, can also occur because of damage to DNA. Such mutations may be of two types: induced or spontaneous. Induced mutations are those that result from an exposure to chemicals, UV rays, x-rays, or some other environmental agent. Spontaneous mutations occur without any exposure to any environmental agent; they are a result of natural reactions taking place within the body. Mutations may have a wide range of effects. Some mutations are not expressed; these are known as silent mutations. Point mutations are those mutations that affect a single base pair. The most common nucleotide mutations are substitutions, in which one base is replaced by another. These can be of two types, either transitions or transversions. Transition substitution refers to a purine or pyrimidine being replaced by a base of the same kind; for example, a purine such as adenine may be replaced by the purine guanine. Transversion substitution refers to a purine being replaced by a pyrimidine, or vice versa; for example, cytosine, a pyrimidine, is replaced by adenine, a purine. Mutations can also be the result of the addition of a base, known as an insertion, or the removal of a base, also known as deletion. Sometimes a piece of DNA from one chromosome may get translocated to another chromosome or to another region of the same chromosome; this is also known as translocation. These mutation types are shown in Figure 14.21. Q: What are the two methods in which mutations arise in dna? Choices: - produced or spontaneous - accelerated or spontaneous - accelerated or random - induced or spontaneous A:
induced or spontaneous
Answer the following question given this paragraph: 7.4 The Thoracic Cage The thoracic cage protects the heart and lungs. It is composed of 12 pairs of ribs with their costal cartilages and the sternum. The ribs are anchored posteriorly to the 12 thoracic vertebrae. The sternum consists of the manubrium, body, and xiphoid process. The manubrium and body are joined at the sternal angle, which is also the site for attachment of the second ribs. Ribs are flattened, curved bones and are numbered 112. Posteriorly, the head of the rib articulates with the costal facets located on the bodies of thoracic vertebrae and the rib tubercle articulates with the facet located on the vertebral transverse process. The angle of the ribs forms the most posterior portion of the thoracic cage. The costal groove in the inferior margin of each rib carries blood vessels and a nerve. Anteriorly, each rib ends in a costal cartilage. True ribs (17) attach directly to the sternum via their costal cartilage. The false ribs (812) either attach to the sternum indirectly or not at all. Ribs 810 have their costal cartilages attached to the cartilage of the next higher rib. The floating ribs (1112) are short and do not attach to the sternum or to another rib. Q: What cage composed of 12 pairs of ribs, with their costal cartilages and the sternum, protects the heart and lungs? Choices: - sacral - lumbar - cervical - thoracic A:
thoracic
Q: Answer the following question given this paragraph: A chloroplast consists of thylakoid membranes surrounded by stroma. The thylakoid membranes contain molecules of the green pigment chlorophyll. Q: What consists of thylakoid membranes surrounded by stroma? Choices: - a photon - a nucleus - a stem - a chloroplast A:
A: a chloroplast
Question: Answer the following question given this paragraph: Pulmonary gas exchange is the exchange of gases between inhaled air and the blood. It occurs in the alveoli of the lungs. Alveoli (singular, alveolus) are grape-like clusters surrounded by networks of thin-walled pulmonary capillaries. After you inhale, there is a greater concentration of oxygen in the alveoli than in the blood of the pulmonary capillaries, so oxygen diffuses from the alveoli into the blood across the capillaries (see Figure below ). Carbon dioxide, in contrast, is more concentrated in the blood of the pulmonary capillaries than in the alveoli, so it diffuses in the opposite direction. Q: In what part of the lungs is pulmonary gas exchanged? Choices: - bronchioles - trachea - bronchi - alveoli A:
Answer: alveoli
*Question*
Answer the following question given this paragraph: Q: Snow and rain are forms of what weather? Choices: - sediment - evaporation - cold fronts - precipitation A:
**Answer**
precipitation
(Q).
Answer the following question given this paragraph: Figure 6.6 Water behind a dam has potential energy. Moving water, such as in a waterfall or a rapidly flowing river, has kinetic energy. (credit "dam": modification of work by "Pascal"/Flickr; credit "waterfall": modification of work by Frank Gualtieri). Q: Water behind a dam has potential energy. moving water, such as in a waterfall or a rapidly flowing river, has this? Choices: - residual energy - thermal energy - compression energy - kinetic energy A:
(A).
kinetic energy