Sleep plays a vital role in defining the daily activities of virtually all animals. During periods of sleep, the parasympathetic nervous system becomes active and induces a relaxed state in response to increased levels of the hormone melatonin. Yet, despite its ubiquity in the animal kingdom, the purpose of sleep and its role in our daily lives has been disputed by scientists. Two scientists discuss their theories about the purpose of sleep.

Scientist 1

During periods of sleep, animals are able to conserve energy that they would otherwise be spending on unnecessary activity. If an animal’s primary food source is most abundant during daylight, it is a waste of precious energy to be moving about at night. For example, many herbivores, such as squirrels, are diurnal (sleep during the night) because their food source is available during the day, while many insectivores, such as bats, are nocturnal (sleep during the day) because their food source is available during the night. Food sources, as an animal’s most valuable resource, dictate their sleep cycles. Many animal traits observable today evolved as a result of the supply and demand of food in their natural habitat.

Scientist 2

During waking hours, it is true that the body utilizes large amounts of energy. However, the role of sleep is to restore biological products that were utilized during periods of wakefulness, rather than simply avoid utilizing energy in the first place. Many types of biological molecules, such as hormones, are released throughout the body while an animal is active. Sleep serves as a period of inactivity during which the body can manufacture and store a supply of these molecules for future use during the next period of activity. Furthermore, sleep allows the body to repair cellular damages that has accumulated during waking hours. Experimental evidence shows that when animals are deprived of sleep, their immune system quickly weakens and death rates increase. Sleep is necessary for animals to prevent accumulation of damage and to regenerate crucial biomolecules for daily life.

Both scientists give evidence to support their theories. The evidence given by Scientist 1 can best be described as __________.

The chart above shows the height growth of three different plant species after a period of 2 weeks. Each plant species was grown in 4 different soil mediums. All the plants were grown in the same environment with equal amounts of light, water, and oxygen.

Based on the chart above, which plant species was consistently taller than the other plant species regardless of soil medium?

A group of scientists wanted to test the effects of Nitra-Grow, a chemical additive that can be given to plants to help them grow. 3 test groups of plants were given all the same time of sunlight, the same type of soil, and the same amount of water. Plant A was given no extra chemicals. Plant B was given 5g of Nitra-Grow. Plant C was given 5g of Ammonia to see if Nitra-Grow worked any better than a basic nitrogen-based household product. The plants are then measured on 5 consecutive days to find their average height (in cm).

What is the general relationship between plant height and the amount of days?

Sleep plays a vital role in defining the daily activities of virtually all animals. During periods of sleep, the parasympathetic nervous system becomes active and induces a relaxed state in response to increased levels of the hormone melatonin. Yet, despite its ubiquity in the animal kingdom, the purpose of sleep and its role in our daily lives has been disputed by scientists. Two scientists discuss their theories about the purpose of sleep.

Scientist 1

During periods of sleep, animals are able to conserve energy that they would otherwise be spending on unnecessary activity. If an animal’s primary food source is most abundant during daylight, it is a waste of precious energy to be moving about at night. For example, many herbivores, such as squirrels, are diurnal (sleep during the night) because their food source is available during the day, while many insectivores, such as bats, are nocturnal (sleep during the day) because their food source is available during the night. Food sources, as an animal’s most valuable resource, dictate their sleep cycles. Many animal traits observable today evolved as a result of the supply and demand of food in their natural habitat.

Scientist 2

During waking hours, it is true that the body utilizes large amounts of energy. However, the role of sleep is to restore biological products that were utilized during periods of wakefulness, rather than simply avoid utilizing energy in the first place. Many types of biological molecules, such as hormones, are released throughout the body while an animal is active. Sleep serves as a period of inactivity during which the body can manufacture and store a supply of these molecules for future use during the next period of activity. Furthermore, sleep allows the body to repair cellular damages that has accumulated during waking hours. Experimental evidence shows that when animals are deprived of sleep, their immune system quickly weakens and death rates increase. Sleep is necessary for animals to prevent accumulation of damage and to regenerate crucial biomolecules for daily life.

Both scientists give evidence to support their theories. The evidence given by Scientist 1 can best be described as __________.

Criminal and deviant acts have plagued society for many years. Scientists have tried to isolate variables and factors of individuals susceptible to these behaviors. The goal of this research is to create models of individuals most likely to commit deviant acts. Prediction of criminal behavior could reduce crime rates on a grand scale. Three scientists express their views on how to model criminal behavior and predict or prevent criminal acts.

Scientist 1

Criminal behavior is the result of prehistoric tendencies that favor aggressive and deviant acts for survival. A study of the corpses of criminals revealed that many exhibited prominent brows, strong upper bodies, large chests and other attributes that lend to a physical model of prediction that classifies criminals as "evolutionary throwbacks."

Scientist 2

Criminal behavior is the result of psychological ills that may be remedied with treatment and hospitalization. Studies have revealed that many criminal men possess an XYY makeup. This means that they contain one extra Y chromosome that results in aggressive, deviant, and criminal behaviors. Further studies have revealed that these genetic abnormalities can alter hormonal secretion and lead to criminally deviant actions and behaviors. Increased serotonin levels can lead to aggressive tendencies while altered dopamine secretion can chemically reward the commitment of deviant acts by stimulating pleasure receptors.

Scientist 3

Criminal behavior is the result of neurological abnormalities that can be studied and mapped. Studies of criminal and non-criminal persons have revealed inconsistencies in brain scans and neurological makeup. These alterations in brain chemistry and function have resulted in the development of sociopathic and narcissistic tendencies. These tendencies often increase probabilities for deviant and violent outbursts. The best way to predict criminal behavior is to utilize neurological scanning and mapping procedures.

A study of mice revealed that males possessing an XYY genotype are far more likely to engage in risky and aggressive behaviors. Which of the scientists would most agree with this evidence?

In the 17th century, scientists were just beginning to understand the circulatory system of the heart. The two following viewpoints are the two most popular theories of the day.

Scientist I The heart pumps blood through arteries and veins but the two systems are separate. They are similar, just as the senses of smell and taste are when observing food, but ultimately they are two separate systems which perform separate functions. Hot blood flows from the heart, through the arteries, and to the organs which consume the blood much as a human would consume nourishment to survive. Venous blood originates in the liver and follows the veins to the organs where it is similarly consumed.

Scientist II The arteries and veins are two parts of one system. Blood flows from the heart, around the body, and back into the heart through the veins like two sets of one way streets. The idea of two systems, each pumping blood to the organs is unreasonable. If the heart can pump 6 oz of blood per minute, then the liver would have to produce 540 pounds of blood per day. A simple measurement of a human’s weight shows how unlikely that solution is. The single circulatory system is far superior as it explains the function of the heart, the arteries, and the veins clearly.

Why does Scientist I compare the arteries and veins to smell and taste?

A mycologist performed an experiment to determine the effect of methanol on the mold Neurospora crassa.

1,500 Neurospora spores were divided evenly into five groups of three large glass test tubes each. Then each test tube was filled with 5.0 mL of liquid nutrient solution and either 0 mL, 0.5 mL, 1.0 mL, 1.5 mL, or 2.0 mL of methanol. The tubes were placed in an incubator at 28oC overnight to germinate, and then their aerial growth was marked beginning the next morning and every twelve hours thereafter for two days.

Table 1 shows the average growth data with hours representing the morning after germination and hours representing the end of the two-day experiment.

In general, the results of the study suggest that Neurospora cultures prepared in liquid media can tolerate at least how many milliliters of methanol and still grow?

Sleep plays a vital role in defining the daily activities of virtually all animals. During periods of sleep, the parasympathetic nervous system becomes active and induces a relaxed state in response to increased levels of the hormone melatonin. Despite its ubiquity in the animal kingdom, the purpose of sleep and its role in our daily lives has been disputed by scientists. Two scientists discuss their theories about the purpose of sleep.

Scientist 1

During periods of sleep, animals are able to conserve energy that they would otherwise be spending on unnecessary activity. If an animal’s primary food source is most abundant during daylight, it is a waste of precious energy to be moving about at night. For example, many herbivores, such as squirrels, are diurnal (sleep during the night) because their food source is available during the day, while many insectivores, such as bats, are nocturnal (sleep during the day) because their food source is available during the night. Food sources, as an animal’s most valuable resource, dictate their sleep cycles. Many animal traits observable today evolved as a result of the supply and demand of food in their natural habitat.

Scientist 2

During waking hours, it is true that the body utilizes large amounts of energy; however, the role of sleep is to restore biological products that were utilized during periods of wakefulness, rather than simply to avoid utilizing energy in the first place. Many types of biological molecules, such as hormones, are released throughout the body while an animal is active. Sleep serves as a period of inactivity, during which the body can manufacture and store a supply of these molecules for future use during the next period of activity. Furthermore, sleep allows the body to repair cellular damages that has accumulated during waking hours. Experimental evidence shows that when animals are deprived of sleep, their immune system quickly weakens and death rates increase. Sleep is necessary for animals to prevent accumulation of damage and to regenerate crucial biomolecules for daily life.

Scientist 1’s theory would be most weakened if which of the following were true?

Sleep plays a vital role in defining the daily activities of virtually all animals. During periods of sleep, the parasympathetic nervous system becomes active and induces a relaxed state in response to increased levels of the hormone melatonin. Despite its ubiquity in the animal kingdom, the purpose of sleep and its role in our daily lives has been disputed by scientists. Two scientists discuss their theories about the purpose of sleep.

Scientist 1

During periods of sleep, animals are able to conserve energy that they would otherwise be spending on unnecessary activity. If an animal’s primary food source is most abundant during daylight, it is a waste of precious energy to be moving about at night. For example, many herbivores, such as squirrels, are diurnal (asleep during the night) because their food source is available during the day, while many insectivores, such as bats, are nocturnal (asleep during the day) because their food source is available during the night. Food sources, as an animal’s most valuable resource, dictate their sleep cycles. Many animal traits observable today evolved as a result of the supply and demand of food in their natural habitat.

Scientist 2

During waking hours, it is true that the body utilizes large amounts of energy; however, the role of sleep is to restore biological products that were utilized during periods of wakefulness, rather than simply to avoid utilizing energy in the first place. Many types of biological molecules, such as hormones, are released throughout the body while an animal is active. Sleep serves as a period of inactivity during which the body can manufacture and store a supply of these molecules, for future use during the next period of activity; furthermore, sleep allows the body to repair cellular damage that has accumulated during waking hours. Experimental evidence shows that when animals are deprived of sleep, their immune system quickly weakens and death rates increase. Sleep is necessary for animals to prevent accumulation of damage and to regenerate crucial biomolecules for daily life.

Studies have shown that students who sleep well the night before an exam receive better marks. Why might this be, according to the hypotheses of both scientists?

Sleep plays a vital role in defining the daily activities of virtually all animals. During periods of sleep, the parasympathetic nervous system becomes active and induces a relaxed state in response to increased levels of the hormone melatonin. Despite its ubiquity in the animal kingdom, the purpose of sleep and its role in our daily lives has been disputed by scientists. Two scientists discuss their theories about the purpose of sleep.

Scientist 1

During periods of sleep, animals are able to conserve energy that they would otherwise be spending on unnecessary activity. If an animal’s primary food source is most abundant during daylight, it is a waste of precious energy to be moving about at night. For example, many herbivores, such as squirrels, are diurnal (asleep during the night) because their food source is available during the day, while many insectivores, such as bats, are nocturnal (asleep during the day) because their food source is available during the night. Food sources, as an animal’s most valuable resource, dictate their sleep cycles. Many animal traits observable today evolved as a result of the supply and demand of food in their natural habitat.

Scientist 2

During waking hours, it is true that the body utilizes large amounts of energy; however, the role of sleep is to restore biological products that were utilized during periods of wakefulness, rather than simply to avoid utilizing energy in the first place. Many types of biological molecules, such as hormones, are released throughout the body while an animal is active. Sleep serves as a period of inactivity during which the body can manufacture and store a supply of these molecules, for future use during the next period of activity; furthermore, sleep allows the body to repair cellular damage that has accumulated during waking hours. Experimental evidence shows that when animals are deprived of sleep, their immune system quickly weakens and death rates increase. Sleep is necessary for animals to prevent accumulation of damage and to regenerate crucial biomolecules for daily life.

Studies have shown that students who sleep well the night before an exam receive better marks. Why might this be, according to the hypotheses of both scientists?