*Question*
Answer the following question given this paragraph: Some solutes, such as sodium acetate, do not recrystallize easily. Suppose an exactly saturated solution of sodium acetate is prepared at 50C. As it cools back to room temperature, no crystals appear in the solution, even though the solubility of sodium acetate is lower at room temperature. A supersaturated solution is a solution that contains more than the maximum amount of solute that is capable of being dissolved at a given temperature. The recrystallization of the excess dissolved solute in a supersaturated solution can be initiated by the addition of a tiny crystal of solute, called a seed crystal. The seed crystal provides a nucleation site on which the excess dissolved crystals can begin to grow. Recrystallization from a supersaturated solution is typically very fast. Q: What is used to recrystallize excess dissolved solute in a supersaturated solution? Choices: - starter crystal - energy crystal - fertilizer crystal - seed crystal A:
**Answer**
seed crystal

*Question*
Answer the following question given this paragraph: Figure 39.21 Individuals with sickle cell anemia have crescent-shaped red blood cells. (credit: modification of work by Ed Uthman; scale-bar data from Matt Russell). Q: Individuals with sickle cell anemia have crescent-shaped what? Choices: - glial cells - white blood cells - nerve cells - red blood cells A:
**Answer**
red blood cells

*Question*
Answer the following question given this paragraph: Interspecific competition happens when individuals of different species strive for a limited resource in the same area. Since any two species have different traits, one species will be able to out-compete the other. One species will be better adapted to its environment, and essentially "win" the competition. The other species will have lower reproductive success and lower population growth, resulting in a lower survival rate. For example, cheetahs and lions feed on similar prey. If prey is limited, then lions may catch more prey than cheetahs. This will force the cheetahs to either leave the area or suffer a decrease in population. Q: What occurs when individuals of different species strive for a limited resource in the same area? Choices: - vegetal competition - asexual competition - intraspecific competition - interspecific competition A:
**Answer**
interspecific competition

*Question*
Answer the following question given this paragraph: Prokaryotic cells are extremely small and have a variety of shapes. Most have flagella and a cell wall. They have several other cell structures as well. Their DNA exists as large and small loops. Some prokaryotes form biofilms, which are colonies of cells stuck to a surface. Q: What are colonies of cells stuck to a surface called? Choices: - membranes - cellular coating - membranes - biofilms A:
**Answer**
biofilms