Answer the following question given this paragraph: The heart is a muscular organ in the chest that consists mainly of cardiac muscle. It pumps blood through blood vessels by repeated, rhythmic contractions. Blood flows through four chambers of the heart when it beats. Heartbeat is controlled by electrical signals from special cells within the heart called the pacemaker. Q: What type of muscle makes up most of the heart? A:

OPTIONS:
- chest muscles
- heart muscle
- respiratory muscle
- cardiac muscle

Answer: cardiac muscle

Answer the following question given this paragraph: Q: Incomplete dominance and epistasis are both terms that define what? A:

OPTIONS:
- learned behaviors
- genetic difficulties
- genetic habits
- genetic relationships

Answer: genetic relationships

Answer the following question given this paragraph: Muscular dystrophy is a term encompassing a variety of muscle wasting diseases. The most common type, Duchenne Muscular Dystrophy (DMD) , affects cardiac and skeletal muscle, as well as some mental functions. DMD is caused by a defective gene for dystrophin, a protein prevalent in skeletal and cardiac muscles. DMD is an X-linked recessive disorder occurring in 1 in 3,500 male newborns. Because DMD is X-linked, no females are affected. Most affected individuals die before their 20th birthday. Daughters of female carriers of the mutant allele have a 50% chance of also being carriers. Q: What type of disease is muscular dystrophy? A:

OPTIONS:
- contagious disease
- mutation
- infectious disease
- a wasting disease

Answer: a wasting disease

Answer the following question given this paragraph: Solubility may increase or decrease with temperature; the magnitude of this temperature dependence varies widely among compounds. Notice in particular the curves for NH4NO3 and CaCl2. The dissolution of ammonium nitrate in water is endothermic (Hsoln = +25.7 kJ/mol), whereas the dissolution of calcium chloride is exothermic (Hsoln = 68.2 kJ/mol), yet Figure 13.9 "Solubilities of Several Inorganic and Organic Solids in Water as a Function of Temperature" shows that the solubility of both compounds increases sharply with increasing temperature. In fact, the magnitudes of the changes in both enthalpy and entropy for dissolution are temperature dependent. Because the solubility of a compound is ultimately determined by relatively small differences between large numbers, there is generally no good way to predict how the solubility will vary with temperature. The variation of solubility with temperature has been measured for a wide range of compounds, and the results are published in many standard reference books. Chemists are often able to use this information to separate the components of a mixture byfractional crystallization, the separation of compounds on the basis of their solubilities in a given solvent. For example, if we have a mixture of 150 g of sodium acetate (CH3CO2Na) and 50 g of KBr, we can separate the two compounds by dissolving the mixture in 100 g of water at 80C and then cooling the solution slowly to 0C. According to the temperature curves in Figure 13.9 "Solubilities of Several Inorganic and Organic Solids in Water as a Function of Temperature", both compounds dissolve in water at 80C, and all 50 g of KBr remains in solution at 0C. Only about 36 g of CH3CO2Na are soluble in 100 g of water at 0C, however, so approximately 114 g (150 g 36 g) of Saylor URL: http://www. saylor. org/books. Q: The separation of compounds on the basis of their solubilities in a given solvent is known as what? A:

OPTIONS:
- nuclei crystallization
- simplest crystallization
- separate crystallization
- fractional crystallization

Answer:
fractional crystallization