Science Flashcards

When it comes to trophic levels, which of the following is correct?

Answer: Tertiary consumers acquire less energy than primary consumers.

Energy transfer between trophic levels is inefficient, with only about 10% of energy being passed on from one level to the next. Primary consumers obtain energy directly from producers, while tertiary consumers feed on secondary consumers, who in turn feed on primary consumers. Therefore, tertiary consumers are several steps removed from the original energy source and acquire significantly less energy than primary consumers, who are closer to the producers.

Why does the human eye see a red dress as 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. A red dress appears red because its molecules absorb most other wavelengths of visible light (like green and blue) but reflect the red wavelengths. These reflected red wavelengths are then detected by our eyes, allowing us to perceive the dress as red.

The type of light used in a lab experiment meant to measure how quickly plants develop when exposed to artificial light is an example of 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 type of light used is the variable being controlled and altered to see how it influences plant development, making it the independent variable. The plant development itself would be the dependent variable.

Metabolism, mood, and growth are regulated by which organ system?

Answer: endocrine system

The endocrine system is a network of glands that produce and secrete hormones, which are chemical messengers. These hormones regulate a wide range of bodily functions, including metabolism (how the body uses energy), mood, growth and development, tissue function, and reproduction. The endocrine system plays a crucial role in maintaining homeostasis and coordinating various physiological processes.

Why, in a vacuum, doesn't an elephant fall to the ground faster than a penny?

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

In a vacuum, all objects fall at the same rate regardless of their mass, due to the constant acceleration caused by gravity. This is because the force of gravity is proportional to mass, and acceleration is force divided by mass (F=ma). Without air resistance, the greater gravitational force on the elephant is exactly offset by its greater mass, resulting in the same acceleration (approximately 9.8 m/s²) as the penny.

Which of the following trains has the most momentum?

Answer: 9500 kg train car moving at 200 mph

Momentum is calculated as the product of an object's mass and its velocity (p = mv). To determine which train car has the most momentum, one must multiply the mass by the speed for each option. The train car with a mass of 9500 kg moving at 200 mph yields the highest product (1,900,000 kg·mph), indicating it possesses the greatest momentum among the choices.

When an invasive species was introduced into a river, a biologist discovered that the local salmon population decreased. The easiest way to sum up the sort of correlation between these two populations is _______.

Answer: an inverse relationship.

An inverse relationship, also known as a negative correlation, occurs when two variables move in opposite directions. In this scenario, as the invasive species population increased, the local salmon population decreased. This opposing trend indicates that one factor's rise is associated with the other factor's decline, characterizing an inverse relationship.

What will happen if a catalyst is added to a chemical reaction?

Answer: Increase the rate at which the reaction takes place.

A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It achieves this by lowering the activation energy required for the reaction to proceed, allowing more reactant molecules to overcome the energy barrier and form products more quickly. Catalysts do not change the equilibrium position or the amount of products formed, only how fast the reaction reaches equilibrium.

In what bodily system does the pharynx belong?

Answer: respiratory

The pharynx, commonly known as the throat, is a muscular tube that serves as a passageway for both air and food. It is a crucial component of the respiratory system, connecting the nasal and oral cavities to the larynx and esophagus. Air passes through the pharynx on its way to the lungs, making it an integral part of the respiratory pathway.

Which statement regarding eukaryotic cells is correct?

Answer: They contain mitochondria.

Eukaryotic cells are characterized by the presence of membrane-bound organelles, including a true nucleus and mitochondria. Mitochondria are often referred to as the "powerhouses" of the cell because they are responsible for cellular respiration, generating most of the cell's supply of adenosine triphosphate (ATP). Unlike prokaryotic cells, eukaryotic cells possess these complex internal structures.

What makes an element's isotope?

Answer: Number of neutrons.

Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons. The number of protons defines the element, so isotopes of an element will always have the same atomic number. However, the varying number of neutrons results in different atomic masses for isotopes of the same element.

When it comes to RNA, what is completely untrue?

Answer: Its sugar is more reduced than DNA’s sugar.

RNA contains ribose sugar, which has a hydroxyl group (-OH) on the 2' carbon. DNA contains deoxyribose sugar, which lacks this oxygen atom, meaning it is "de-oxygenated" or more reduced compared to ribose. Therefore, the statement that RNA's sugar is *more* reduced than DNA's sugar is incorrect; DNA's sugar is more reduced.

Which scenario does not provide a normal distribution?

Answer: The percentage of toxic wastes and pollution in the atmosphere vs. the lifespan of organisms in the location.

A normal distribution is a symmetrical, bell-shaped curve where data points cluster around the mean, with fewer points further away. The relationship between toxic waste/pollution and organism lifespan is likely to be a negative correlation (more pollution, shorter lifespan) and not necessarily symmetrical or bell-shaped. Factors like height and income can often approximate a normal distribution, but a direct cause-effect relationship like pollution and lifespan would typically not follow this pattern.

Where in a cell is the Golgi apparatus located?

Answer: In the cytoplasm

The Golgi apparatus, also known as the Golgi complex or Golgi body, is a membrane-bound organelle found in the cytoplasm of eukaryotic cells. It plays a vital role in modifying, sorting, and packaging proteins and lipids synthesized in the endoplasmic reticulum for secretion or delivery to other organelles. It is a distinct structure within the cell's cytoplasm, separate from the nucleus or mitochondria.

What's the next-smallest taxonomic level after Order?

Answer: Family

The hierarchical classification system for living organisms, from broadest to most specific, is: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. Following "Order," the next smaller and more specific taxonomic level is "Family." This system helps scientists categorize and understand the relationships between different organisms.

_______ includes the production of a ____ in plants?

Answer: cytokinesis, cell plate

Cytokinesis is the final stage of cell division, where the cytoplasm divides to form two separate daughter cells. In plant cells, this process involves the formation of a cell plate in the middle of the cell, which grows outwards to fuse with the existing cell wall, eventually forming a new cell wall that separates the two daughter cells. This is distinct from animal cell cytokinesis, which involves a cleavage furrow.

Which of these is NOT a part of DNA?

Answer: uracil

DNA (deoxyribonucleic acid) is composed of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Uracil (U) is a nitrogenous base found in RNA (ribonucleic acid), where it replaces thymine. Therefore, uracil is not a component of DNA.

Which atmosphere layer is nearest to space?

Answer: thermosphere

The Earth's atmosphere is divided into several layers based on temperature profiles. Moving upwards from the Earth's surface, these layers are the troposphere, stratosphere, mesosphere, and thermosphere. The thermosphere is the outermost layer before the exosphere, which gradually fades into space, making it the layer nearest to space among the options provided.

Which of the following is NOT a form of tissue?

Answer: parenchyma

In biology, the four primary types of animal tissues are epithelial, connective, muscular, and nervous tissue. Parenchyma, on the other hand, is a type of plant tissue, specifically a fundamental tissue found in the cortex and pith of stems, roots, and in the mesophyll of leaves. Therefore, parenchyma is not a form of animal tissue.

______ the small intestine is the stomach. Which completes the sentence? Which completes the sentence?

Answer: superior

In anatomical terms, "superior" means above or towards the head. The stomach is located above the small intestine in the human body. Therefore, the stomach is superior to the small intestine, indicating its position relative to the small intestine.