Science Flashcards

What would this diagram be useful for?

Answer: determining outcomes for potential infection

Without the actual diagram, we infer its purpose from the correct answer. A diagram useful for 'determining outcomes for potential infection' would likely be a flowchart or decision tree that guides a user through various symptoms, test results, or exposure scenarios. By following the paths in the diagram, one could predict the probable course, severity, or specific type of infection, helping to understand potential future developments rather than providing an immediate diagnosis or control strategy.

What type of bond between the complementary bases of DNA stabilizes the double helix structure?

Answer: hydrogen

The double helix structure of DNA is primarily stabilized by hydrogen bonds that form between complementary nitrogenous bases. Adenine (A) always pairs with Thymine (T) via two hydrogen bonds, and Guanine (G) always pairs with Cytosine (C) via three hydrogen bonds. These relatively weak but numerous bonds collectively provide the necessary stability to maintain the DNA's helical shape, while also allowing the strands to separate for replication and transcription.

Which of the following subatomic particles are found inside of an atom’s nucleus?

Answer: neutrons, protons

An atom's nucleus is the dense, central core that contains two types of subatomic particles: protons and neutrons. Protons carry a positive electrical charge, while neutrons are electrically neutral, meaning they have no charge. Electrons, which carry a negative charge, are found orbiting the nucleus in electron shells, not within the nucleus itself.

Which of the following statements is true regarding trophic levels?

Answer: Tertiary consumers acquire less energy than primary consumers.

Energy transfer between trophic levels is highly inefficient, following the '10% rule' where only about 10% of the energy from one level is transferred to the next. Primary consumers acquire energy directly from producers. Tertiary consumers are several steps removed from the original energy source, feeding on secondary consumers. Consequently, tertiary consumers receive a significantly smaller amount of the initial energy compared to primary consumers, resulting in less energy content at higher trophic levels.

Why does the human eye perceive a red colored dress as the color red?

Answer: The molecules of the dress do not absorb red light wavelengths.

The color an object appears to be is determined by the wavelengths of light it reflects. When white light (which contains all colors) strikes a red dress, the molecules in the dress absorb most of the non-red wavelengths (like blue, green, and yellow). The red wavelengths, however, are not absorbed and are instead reflected off the dress. Our eyes then detect these reflected red wavelengths, causing us to perceive the dress as red.

In a lab experiment designed to test the rate at which plants grow under artificial light, the kind of light used is which type of variable?

Answer: independent

In a scientific experiment, the independent variable is the factor that is intentionally changed or manipulated by the experimenter to observe its effect. In this scenario, the scientist is specifically varying the 'kind of light used' to see how it influences plant growth. Therefore, the type of light is the variable that is controlled and altered by the researcher, making it the independent variable.

Which organ system is primarily responsible for regulating metabolism, mood, and growth?

Answer: endocrine system

The endocrine system is a complex network of glands that produce and secrete hormones, which are chemical messengers, directly into the bloodstream. These hormones regulate a vast array of bodily functions, including metabolism (how the body uses energy), growth and development, tissue function, sexual function, reproduction, sleep, and mood. The other listed systems have distinct primary roles.

In a vacuum, why doesn’t an elephant accelerate faster than a penny as it falls to the ground?

Answer: They both have an acceleration of 9.8 m/s2

In a vacuum, there is no air resistance to impede falling objects. According to the principles of physics, all objects, regardless of their mass, fall with the same constant acceleration due to gravity near the Earth's surface. This acceleration is approximately 9.8 m/s², meaning both an elephant and a penny would accelerate at the same rate and hit the ground simultaneously if dropped from the same height in a vacuum.

Which train described below would have the greatest momentum?

Answer: A 9500 kg train car moving at 200 mph

Momentum (p) is calculated as the product of an object's mass (m) and its velocity (v), represented by the formula p = mv. To determine which train car has the greatest momentum, we calculate this product for each option: A) 9500 kg * 200 mph = 1,900,000; B) 8000 kg * 215 mph = 1,720,000; C) 9300 kg * 190 mph = 1,767,000; D) 8600 kg * 195 mph = 1,677,000. Option A yields the highest momentum value.

The graph above records the death rate of two types of male flies a certain number of days after a chemical pesticide is sprayed. What is the probability a male methuselah fly will be alive 75 days after exposure to the pesticide?

Answer: 1/5

To determine the probability a male methuselah fly will be alive 75 days after exposure, one would need to consult the provided graph. Assuming the graph plots survival rate over time, locate 75 days on the x-axis and then find the corresponding point on the curve for 'methuselah fly.' If that point aligns with a survival probability of 0.2 (or 20%) on the y-axis, then 0.2 is equivalent to the fraction 1/5, indicating that one out of five flies would still be alive.

A scientist wants to write an equation using the variables X, Y, and Z. What is the proper relationship between the variables if X represents time, Y represents energy, and Z represents power?

Answer: Z = Y/X

Power (Z) is fundamentally defined as the rate at which energy (Y) is transferred or converted per unit of time (X). This relationship is expressed by the formula Power = Energy / Time. Therefore, when substituting the given variables, the correct equation representing this physical relationship is Z = Y/X.

What type of correlation is presented between price and quality?

Answer: weak direct correlation

A direct (or positive) correlation implies that as one variable increases, the other variable also tends to increase. In many consumer markets, there's a general tendency for higher-priced goods to be associated with higher quality. However, this relationship is not always perfectly consistent; there are exceptions where high-priced items can be of low quality, or vice-versa. This variability suggests that while a direct relationship exists, it is not consistently strong, hence a 'weak direct correlation.'

What type of cells result from mitosis?

Answer: two diploid cells

Mitosis is a type of cell division that produces two genetically identical daughter cells from a single parent cell. During mitosis, a diploid parent cell (containing two complete sets of chromosomes) undergoes division to create two new cells, each also diploid and containing the same number of chromosomes as the original parent cell. This process is crucial for growth, tissue repair, and asexual reproduction.

Cheetahs, rainbow trout, and inchworms belong to the same

Answer: Kingdom

Cheetahs (mammals), rainbow trout (fish), and inchworms (insects) are all multicellular organisms that obtain nutrients by consuming other organisms (heterotrophic). These fundamental characteristics classify them all within the Kingdom Animalia. While they belong to vastly different phyla, classes, and orders due to their diverse evolutionary paths and physical traits, they share the defining features of the animal kingdom.

The presence of which hormone would NOT cause an increase in water retention?

Answer: ANP

Atrial Natriuretic Peptide (ANP) is a hormone released by the heart in response to increased blood volume and pressure. Its primary function is to promote the excretion of sodium and water by the kidneys, leading to a decrease in blood volume and pressure. In contrast, Renin, ADH (Antidiuretic Hormone), and Aldosterone all act to increase water and sodium retention, thereby raising blood volume and blood pressure.

Which of the following describes the flow of oxygenated blood from the heart to the body?

Answer: systemic circulation

Systemic circulation is the major circuit of the cardiovascular system responsible for transporting oxygenated blood from the left side of the heart, through the aorta, to all the tissues and organs of the body. After delivering oxygen and nutrients, it then returns deoxygenated blood back to the right side of the heart. This contrasts with pulmonary circulation, which moves blood between the heart and lungs.

In which of the following structures of the mammalian digestive system is it most likely that nutrients will be absorbed?

Answer: duodenum

The duodenum is the first and shortest segment of the small intestine, and it is the primary site for the chemical digestion of chyme (partially digested food) from the stomach and the absorption of most nutrients. Its inner lining is highly folded into villi and microvilli, which significantly increase the surface area available for efficient absorption of digested carbohydrates, proteins, and fats into the bloodstream.

Which of the following best describes the movement of an action potential along a neuron's axon?

Answer: saltatory conduction

Saltatory conduction is the process by which action potentials propagate along myelinated axons. Instead of continuously traveling along the entire axon membrane, the electrical impulse 'jumps' from one node of Ranvier (gaps in the myelin sheath) to the next. This jumping mechanism significantly increases the speed of nerve impulse transmission, allowing for rapid communication within the nervous system.

Which of the following best describes the process by which air is inhaled into the respiratory system of a human?

Answer: the diaphragm contracts and lowers, making the air pressure in the lungs decrease.

During inhalation, the diaphragm, a dome-shaped muscle, contracts and moves downwards, while the external intercostal muscles contract to lift the rib cage. These actions increase the volume of the thoracic cavity. According to Boyle's Law, an increase in volume leads to a decrease in the air pressure inside the lungs, creating a pressure gradient that causes air from the higher-pressure atmosphere to rush into the lungs.

Which of the following best describes the order in which an inflammatory reaction takes place? I. Phagocytes are drawn to the area that is injured. II. Blood vessels start to leak. III. Histamine is released by damaged cells. IV. Pus starts to develop.

Answer: III, II, I, IV

An inflammatory reaction typically follows a specific sequence. First, damaged cells release chemical mediators like histamine (III). This causes local blood vessels to dilate and become more permeable, leading to leakage of fluid and immune cells into the injured area (II). Next, phagocytes, such as neutrophils and macrophages, are attracted to the site to engulf pathogens and cellular debris (I). Finally, if the infection or damage is severe, the accumulation of dead cells and immune components can result in the formation of pus (IV).