1.
Which sequence correctly lists the different levels of biological organization?
Correct Answer
E. E. cells -> tissues -> organs -> organ system -> organism
Explanation
The correct answer is E. This sequence correctly lists the different levels of biological organization, starting from the smallest unit (cells) and progressing to larger structures (tissues, organs, organ systems, and finally the whole organism). This sequence follows the hierarchical organization of living organisms, where cells combine to form tissues, tissues combine to form organs, organs work together to form organ systems, and all of these components come together to form a complete organism.
2.
Characteristics of life include all BUT
Correct Answer
D. D. mimicry
Explanation
Mimicry is not considered a characteristic of life because it is a behavior or adaptation that some organisms use to imitate or resemble other organisms or objects in their environment. While mimicry can be a survival strategy, it is not an inherent characteristic of living organisms. The other options, growth and development, reproduction, and energy use, are all fundamental characteristics of life that are necessary for the survival and continuation of living organisms.
3.
Domains or "superkingdoms" include all BUT
Correct Answer
D. D. Animalia
Explanation
The question is asking which option is NOT included in the domains or "superkingdoms." The domains include Bacteria, Archaea, and Eukarya. Animalia, which refers to the kingdom of animals, is not a domain or "superkingdom" and is therefore not included.
4.
Charles Darwin proposed the theory of evolution by the mechanism of ____________.
Correct Answer
B. B. natural selection
Explanation
Charles Darwin proposed the theory of evolution by the mechanism of natural selection. This theory states that individuals with favorable traits are more likely to survive and reproduce, passing on those traits to future generations. Over time, this process leads to the gradual change and adaptation of species to their environment. Natural selection is a key mechanism in Darwin's theory of evolution and is supported by extensive evidence from various fields of study.
5.
Principles of a theory include all BUT
Correct Answer
C. C. explains natural pHenomen
Explanation
The principles of a theory include a body of interconnected concepts, expressing ideas of which we are most certain, and being supported by much experimental evidence. However, the principles of a theory do not necessarily include explaining natural phenomena.
6.
The atomic weight of an element is calculated by
Correct Answer
C. C. number of protons + neutrons
Explanation
The atomic weight of an element is calculated by adding the number of protons and neutrons in the nucleus of an atom. Protons have a positive charge and neutrons have no charge, therefore their combined number represents the mass of the atom. Electrons, on the other hand, have a negligible mass compared to protons and neutrons, so they are not included in the calculation of atomic weight. Therefore, the correct answer is C. number of protons + neutrons.
7.
Covalent bonding is described as
Correct Answer
A. A. sharing of electrons
Explanation
Covalent bonding is a type of chemical bonding where atoms share electrons. This sharing of electrons allows both atoms to achieve a stable electron configuration, resulting in a more stable molecule. In covalent bonding, neither atom completely loses or gains electrons, but rather they share them in order to fill their outermost electron shells. This type of bonding is typically found between nonmetal atoms.
8.
How many electrons is required for an element to be stable, in essence non-reactive
Correct Answer
C. C. eight
Explanation
The answer is C. eight. This is because elements strive to have a full outer electron shell, which typically consists of eight electrons. When an element has a full outer shell, it is stable and less likely to react with other elements. This is known as the octet rule. Therefore, eight electrons are required for an element to be stable and non-reactive.
9.
Polar molecules are generated by
Correct Answer
B. B. covalent bonding
Explanation
Covalent bonding is the correct answer because polar molecules are formed when two atoms share electrons unequally. In a covalent bond, atoms share electrons to achieve a stable electron configuration. If the atoms have different electronegativities, the shared electrons will spend more time closer to the atom with the higher electronegativity, creating a partial positive charge on one atom and a partial negative charge on the other. This uneven distribution of charge results in a polar molecule. Ionic bonding (option A) involves the transfer of electrons, not sharing, and leads to the formation of ions. Cations (option C) and anions (option D) are charged particles formed by the gain or loss of electrons, not the formation of polar molecules.
10.
As air temperaturewarms duringthe day from 50 to 70 degrees, water in the same area will
Correct Answer
C. C. warm more slowly
Explanation
As air temperature warms during the day from 50 to 70 degrees, water in the same area will warm more slowly. This is because water has a higher specific heat capacity compared to air. Specific heat capacity is the amount of heat energy required to raise the temperature of a substance by a certain amount. Since water has a higher specific heat capacity, it requires more heat energy to raise its temperature compared to air. Therefore, the water will warm at a slower rate than the air.
11.
Organic compounds are categorized into four classes including all EXCEPT
Correct Answer
A. A. water
Explanation
Organic compounds are compounds that contain carbon atoms bonded to hydrogen atoms. They are classified into four main classes: lipids, proteins, nucleic acids, and carbohydrates. Water, however, is not considered an organic compound because it does not contain carbon atoms bonded to hydrogen atoms. Therefore, the correct answer is A. water.
12.
Features of the element, carbon, include all BUT
Correct Answer
D. D. forms ionic bonds
Explanation
Carbon is known for its ability to form covalent bonds, meaning it shares electrons with other atoms. It has 4 electrons in its outer shell, making it versatile for bonding. Additionally, carbon is a key component of organic compounds, along with hydrogen. However, carbon does not typically form ionic bonds, where electrons are transferred between atoms. This is because carbon's electronegativity is not high enough to attract electrons strongly enough for ionic bonding.
13.
Lipids include all BUT
Correct Answer
B. B. albumin
Explanation
Lipids are a diverse group of molecules that include phospholipids, waxes, and steroids. Phospholipids are a major component of cell membranes, waxes are found in the protective coatings of plants and animals, and steroids are important for various physiological functions. However, albumin is a protein and not a lipid. It is a soluble protein found in blood plasma and plays a role in maintaining osmotic pressure and transporting molecules.
14.
Ose is a common suffix with which type of compounds?
Correct Answer
A. A. sugars
Explanation
The suffix "ose" is commonly found in the names of sugars. This suffix is used to indicate that a compound is a sugar, such as glucose, fructose, and sucrose. Therefore, option A is the correct answer.
15.
What characteristic of a protein will determine its function?
Correct Answer
B. B. shape
Explanation
The shape of a protein is a critical characteristic that determines its function. Proteins are made up of long chains of amino acids that fold into specific three-dimensional shapes. This shape is essential for the protein to interact with other molecules and perform its specific function. Different shapes allow proteins to bind to specific targets, catalyze chemical reactions, transport molecules, or provide structural support. Therefore, the shape of a protein directly influences its ability to carry out its intended function.
16.
Which association is NOT correct?
Correct Answer
B. B. carbohydrates - enzymes
Explanation
Carbohydrates are not directly associated with enzymes. Carbohydrates are a type of macromolecule that serve as a source of energy and provide structural support, while enzymes are proteins that act as catalysts in biochemical reactions. Although enzymes can interact with carbohydrates in certain reactions, the association between carbohydrates and enzymes is not a direct one.
17.
Which of the following DOES NOT apply to carbohydrates?
Correct Answer
C. C. may be saturated or unsaturated
Explanation
Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen atoms. They can be classified into three main types: monosaccharides, disaccharides, and polysaccharides. Complex carbohydrates include starches and glycogen. However, the concept of saturation or unsaturation is not applicable to carbohydrates. This property is typically associated with fats and oils, which are composed of different types of fatty acids. Therefore, option C does not apply to carbohydrates.
18.
A nucleotide consists of
Correct Answer
B. B. a sugar, a nitrogenous base, and a pHospHate group
Explanation
A nucleotide is a building block of nucleic acids, such as DNA and RNA. It consists of three main components: a sugar molecule (either deoxyribose or ribose), a nitrogenous base (adenine, thymine, cytosine, guanine, or uracil), and a phosphate group. These components are joined together to form a nucleotide, which then combine with other nucleotides to form the DNA or RNA molecule. Therefore, option B is the correct answer as it accurately describes the composition of a nucleotide.
19.
Appropriate descriptions for a plasma mebrane include all BUT
Correct Answer
B. B. rigid
Explanation
The plasma membrane is a flexible and dynamic structure that surrounds the cell. It is composed of a phospholipid bilayer that allows for fluid movement of molecules. The term "mosaic" refers to the presence of various proteins and lipids embedded in the membrane, giving it a mosaic-like appearance. Lastly, the plasma membrane is selectively permeable, meaning it regulates the passage of substances in and out of the cell. However, it is not rigid, as it needs to be flexible to accommodate cellular processes such as endocytosis and cell movement.
20.
Types of passive transport include all BUT
Correct Answer
C. C. receptor-mediated
Explanation
Passive transport is a process in which substances move across a cell membrane without the use of energy. Diffusion, facilitated diffusion, and osmosis are all examples of passive transport. Diffusion is the movement of molecules from an area of high concentration to an area of low concentration. Facilitated diffusion is the movement of molecules across the membrane with the help of transport proteins. Osmosis is the movement of water molecules across a selectively permeable membrane. Receptor-mediated transport, on the other hand, involves the binding of a substance to a specific receptor on the cell membrane, which then triggers the transport of the substance into the cell. Therefore, receptor-mediated transport is not a type of passive transport.
21.
A solution that has a higher concentration of solute and a lower concentration of water than inside the cell is
Correct Answer
C. C. hypertonic solution
Explanation
A hypertonic solution has a higher concentration of solute and a lower concentration of water compared to inside the cell. When a cell is placed in a hypertonic solution, water will flow out of the cell to try to equalize the concentration of solute on both sides of the cell membrane. This causes the cell to shrink or shrivel up.
22.
Forms of endocytosis include all BUT
Correct Answer
A. A. exocytosis
Explanation
Exocytosis is the process by which cells release substances from inside the cell to the outside. It is the opposite of endocytosis, which is the process by which cells take in substances from the outside. Therefore, exocytosis is not a form of endocytosis, making it the correct answer. Phagocytosis, pinocytosis, and receptor-mediated endocytosis are all forms of endocytosis, where cells take in solid particles, liquid particles, and specific molecules, respectively.
23.
An isotonic solution means that the solute concentraion outside the cell is
Correct Answer
A. A. is the same as inside the cell
Explanation
An isotonic solution refers to a solution where the solute concentration is the same inside and outside the cell. In this scenario, there is no net movement of water across the cell membrane, as the concentration of solutes is balanced on both sides. This allows the cell to maintain its shape and normal functions without any water loss or gain.
24.
Which of thefollowing is (are) true about facilitated diffusion?
Correct Answer
E. E.all of the above
Explanation
Facilitated diffusion is a passive transport process that allows the movement of specific molecules across a cell membrane with the help of transport proteins. The given answer, "E. all of the above," is correct because facilitated diffusion requires a concentration gradient, a membrane through which the molecules can pass, involves proteins (specifically transport proteins), and does not require an outside energy source. Therefore, all of the statements mentioned in options A, B, C, and D are true about facilitated diffusion.
25.
White blood cells engulf bacteria through what process
Correct Answer
B. B. pHagocytosis
Explanation
Phagocytosis is the process by which white blood cells engulf and ingest bacteria. This process involves the formation of pseudopodia, which surround and engulf the bacteria, forming a phagosome. The phagosome then fuses with lysosomes, forming a phagolysosome, where the bacteria are broken down and destroyed. This is an important mechanism of the immune system to eliminate harmful bacteria and other pathogens from the body.
26.
Which of the following processes result(s) from the presence of proteins in or on the plasma membrane?
Correct Answer
E. E. all of the above
Explanation
Proteins play a crucial role in various processes in or on the plasma membrane. They can act as enzymes, catalyzing biochemical reactions and facilitating metabolic processes (A. enzymatic activity). Proteins also contribute to cell-cell recognition, allowing cells to identify and interact with each other (B. cell-cell recognition). Additionally, proteins are involved in active transport, which is the movement of molecules across the membrane against their concentration gradient (C. active transport). Lastly, proteins are essential for cell-cell communication, enabling cells to send and receive signals (D. cell-cell communication). Therefore, all of the mentioned processes result from the presence of proteins in or on the plasma membrane (E. all of the above).
27.
Substances that may pass through a plasma membrane without energy include
Correct Answer
C. C. lipid-soluble materials
Explanation
Lipid-soluble materials can pass through a plasma membrane without the need for energy because the plasma membrane is made up of a lipid bilayer. Lipid-soluble materials can dissolve in the lipid bilayer and easily pass through the membrane. In contrast, large food molecules and ions are not lipid-soluble and therefore cannot pass through the plasma membrane without the assistance of transport proteins or energy.
28.
The sum of all chemical reactions occurring inside a living cell is called
Correct Answer
A. A. metabolism
Explanation
Metabolism refers to the sum of all chemical reactions that take place within a living cell. These reactions include both catabolic reactions, which break down molecules to release energy, and anabolic reactions, which build up molecules using energy. Therefore, metabolism encompasses all the processes involved in converting food into energy, synthesizing new molecules, and maintaining the overall functioning of the cell.
29.
Enzymes ___________ energy of activation requred for reactions to occur.
Correct Answer
B. B. decrease
Explanation
Enzymes are biological catalysts that speed up chemical reactions in cells. They do this by lowering the energy of activation required for the reactions to occur. By decreasing the energy of activation, enzymes make it easier for the reactants to reach the transition state and proceed with the reaction. This allows reactions to happen more quickly and efficiently. Therefore, the correct answer is B. decrease.
30.
Whenever energy is transformed, there is always an increase in the
Correct Answer
D. D. entropy of the universe
Explanation
Whenever energy is transformed, there is always an increase in the entropy of the universe. This is because the second law of thermodynamics states that in any energy transfer or transformation, the total entropy of an isolated system will always increase over time. Entropy is a measure of the disorder or randomness in a system, and as energy is transformed, it tends to disperse and increase the overall disorder in the universe. Therefore, the correct answer is D. entropy of the universe.
31.
Types of reaction in which energy is released, may occur with the breakdown of ATPand products willhave less energy than the reactants are descriptions of
Correct Answer
D. D. exergonic reactions
Explanation
The given descriptions of reactions that involve the breakdown of ATP and result in products with less energy than the reactants align with the characteristics of exergonic reactions. In exergonic reactions, energy is released, and the products have lower energy than the reactants. This energy release is often used to drive cellular processes. Therefore, option D, exergonic reactions, is the correct answer.
32.
The reactants in an enzymatic reaction are called the substrates for that enzyme.
Correct Answer
A. True
Explanation
In an enzymatic reaction, the reactants are referred to as substrates because they are the molecules that the enzyme acts upon. Enzymes are proteins that catalyze chemical reactions by binding to specific substrates and facilitating their conversion into products. The substrates bind to the active site of the enzyme, where the reaction takes place. Therefore, it is correct to say that the reactants in an enzymatic reaction are called the substrates for that enzyme.
33.
When a substrate binds to the enzyme, the active site undergoes a slight alteration to achieve best fit, called
Correct Answer
B. B. induced fit model
Explanation
The correct answer is B. induced fit model. In the induced fit model, when a substrate binds to the enzyme, the active site undergoes a slight alteration to achieve the best fit. This means that the enzyme is not rigid, but rather flexible and can change its shape to accommodate the substrate. This model suggests that both the enzyme and the substrate undergo conformational changes upon binding, leading to a more optimal fit and increased catalytic activity.
34.
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as
Correct Answer
B. B. feedback inhibition
Explanation
Feedback inhibition is the mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway. This allows the cell to regulate the production of certain molecules based on the levels of the end product. When the end product reaches a certain concentration, it binds to an enzyme involved in an earlier step of the pathway, causing a conformational change that inhibits the enzyme's activity. This helps maintain homeostasis and prevent the overproduction of certain molecules.
35.
Factors that affectenzymatic reactions and their speed include
Correct Answer
D. D. all of the above
Explanation
The correct answer is D. all of the above. Enzymatic reactions are affected by temperature and pH because enzymes have an optimal temperature and pH range at which they function most efficiently. Inhibitors can also affect enzymatic reactions by binding to the enzyme and preventing it from carrying out its normal function. The amounts of substrate and enzyme also play a role in the speed of enzymatic reactions. If there is an excess of substrate or enzyme, the reaction may proceed faster, while a limited amount of either can slow down the reaction. Therefore, all of these factors can affect enzymatic reactions and their speed.
36.
Which molecule is considered to the energy currency of cells?
Correct Answer
D. D. ATP
Explanation
ATP (adenosine triphosphate) is considered the energy currency of cells because it is the molecule that carries and provides energy for cellular processes. When ATP is hydrolyzed, it releases energy that can be used by cells to perform various functions such as muscle contraction, active transport, and synthesis of macromolecules. Glucose is a source of energy, but it needs to be broken down into ATP before it can be used. Oxygen is involved in cellular respiration but is not the actual energy currency. Proteins are essential for various cellular functions but do not directly serve as the energy currency.
37.
Which of the following equations represent the overall reaction of aerobic cellular respiration?
Correct Answer
C. C. C^6H^12O^6 + 6O^2 ----> 6CO^2 + 6H^2O + ATP
Explanation
The correct answer is C because it represents the overall reaction of aerobic cellular respiration. In this reaction, glucose (C6H12O6) is combined with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O), while also generating ATP. This equation accurately reflects the process of aerobic cellular respiration, where glucose is broken down in the presence of oxygen to release energy in the form of ATP, along with the production of carbon dioxide and water as waste products.
38.
Which organelle is responsiblefor the production of energy for our cells?
Correct Answer
B. B. mitochondria
Explanation
Mitochondria are responsible for the production of energy for our cells. They are often referred to as the "powerhouses" of the cell because they generate adenosine triphosphate (ATP), which is the main source of energy for cellular processes. Mitochondria have their own DNA and are able to produce their own proteins, allowing them to carry out the process of cellular respiration and produce ATP through oxidative phosphorylation. This energy production is essential for the functioning of our cells and overall organism.
39.
Referring to the overall reaction of aerobic respiration, the reactants involved include
Correct Answer
A. A. glucose and oxygen
Explanation
In aerobic respiration, glucose and oxygen are the reactants involved. Glucose is broken down in the presence of oxygen to produce carbon dioxide, water, and ATP. However, the question is asking for the reactants involved in the overall reaction, not the products. The overall reaction can be summarized as: glucose + oxygen → carbon dioxide + water + ATP. Therefore, the correct answer is A. glucose and oxygen.
40.
Glycolysis results in the formation of the products
Correct Answer
B. B. pyruvate, NADH, and ATP
Explanation
Glycolysis is the metabolic pathway that breaks down glucose into pyruvate. During this process, NADH and ATP are also produced. Therefore, option B, which includes pyruvate, NADH, and ATP, is the correct answer.
41.
Citric acid cycle begins with the formationof the reactant(s)
Correct Answer
B. B. acetyl-CoA
Explanation
The citric acid cycle, also known as the Krebs cycle, is a series of chemical reactions that occur in the mitochondria of cells. It is an important part of cellular respiration, where glucose is broken down to produce energy in the form of ATP. The cycle begins with the formation of acetyl-CoA, which is derived from pyruvate. Acetyl-CoA enters the cycle and combines with oxaloacetate to form citrate, starting the series of reactions. Therefore, the correct answer is B. acetyl-CoA.
42.
Among the three stages of aerobic respiration, thelargest amount of ATP payoff occurs
Correct Answer
C. C. oxidative pHospHorolation
Explanation
The largest amount of ATP payoff occurs in oxidative phosphorylation. This stage of aerobic respiration occurs in the mitochondria and involves the transfer of electrons from NADH and FADH2 to the electron transport chain. As the electrons are passed along the chain, protons are pumped across the inner mitochondrial membrane, creating an electrochemical gradient. This gradient is then used by ATP synthase to produce ATP through chemiosmosis. Overall, oxidative phosphorylation produces the majority of the ATP molecules generated during aerobic respiration.
43.
The type of respiration that occurs within animal muscle cells to accomplish a quick energy gain is called
Correct Answer
A. A. lactic acid fermentation
Explanation
Lactic acid fermentation is the correct answer because it is the type of respiration that occurs within animal muscle cells to quickly gain energy. During intense exercise, when oxygen supply is limited, muscle cells switch to lactic acid fermentation to produce ATP. This process breaks down glucose into lactic acid, releasing energy in the process. This allows the muscles to continue contracting even without sufficient oxygen supply.
44.
Which of the following statements about Kreb's cycle is NOT correct?
Correct Answer
C. C. two oxygen molecules are reactants
Explanation
The Kreb's cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the matrix of mitochondria. It is an important part of cellular respiration, where glucose is broken down to produce energy in the form of ATP. In this cycle, carbon dioxide is indeed produced as a waste product. NADH and FADH are also produced, which are important electron carriers that play a role in the electron transport chain. Acetyl-CoA is a reactant that enters the cycle. However, oxygen is not directly involved as a reactant in the Kreb's cycle. Therefore, statement C is not correct.
45.
Which of the following statements about electron transport chain is NOT correct?
Correct Answer
E. E. NADH and FADH products
Explanation
The electron transport chain is a series of protein complexes located in the cristae of the mitochondria. It is responsible for generating a large amount of ATP through oxidative phosphorylation. Oxygen is a reactant in this process, as it acts as the final electron acceptor. NADH and FADH are not products of the electron transport chain; rather, they are the molecules that donate electrons to the chain. Therefore, option E is the correct answer as it incorrectly states that NADH and FADH are products of the electron transport chain.
46.
The centromere is a region in which
Correct Answer
A. A. chromatids remain attached to one another until anapHase
Explanation
The centromere is a region in which chromatids remain attached to one another until anaphase. This is because the centromere is the point of attachment for the spindle fibers during cell division. The spindle fibers pull the chromatids apart during anaphase, leading to the formation of two separate chromosomes. Therefore, the correct answer is A. chromatids remain attached to one another until anaphase.
47.
What is a chromatid?
Correct Answer
B. B. a replicate chromosome
Explanation
A chromatid is a replicate chromosome, meaning it is an identical copy of a chromosome that is formed during DNA replication. During cell division, each chromatid is separated and becomes a separate chromosome in each of the two daughter cells. This process ensures that each daughter cell receives a complete set of genetic information.
48.
Which term describes centromeres uncoupling, sister chromatids separating, and the two new chromosomes moving to opposite poles of the cell?
Correct Answer
B. B. anapHase
Explanation
Anaphase is the correct answer because it is the phase of mitosis where the sister chromatids separate and move to opposite poles of the cell. During anaphase, the centromeres uncouple and the two new chromosomes are pulled apart by the spindle fibers towards the opposite ends of the cell. This is a crucial step in cell division as it ensures that each daughter cell receives a complete set of chromosomes.
49.
Chromosomes first become visible during which phase of mitosis?
Correct Answer
C. C. propHase
Explanation
During prophase, the chromosomes condense and become visible under a microscope. This is the first stage of mitosis, where the nuclear envelope starts to break down and the spindle fibers begin to form. In prometaphase, the nuclear envelope fully disintegrates and the spindle fibers attach to the chromosomes. In metaphase, the chromosomes align at the center of the cell. In anaphase, the sister chromatids separate and move towards opposite poles of the cell. In telophase, the chromosomes reach the poles and the nuclear envelope reforms.
50.
Why do chromosomes coil during mitosis?
Correct Answer
B. B. to allow the chromosomes to move without becoming entangled and breaking
Explanation
Chromosomes coil during mitosis to allow them to move without becoming entangled and breaking. As the cell prepares for division, the chromosomes condense and coil up into a compact structure. This coiling helps prevent the chromosomes from getting tangled up with each other or breaking during the process of cell division. By coiling up, the chromosomes can easily separate and move to opposite ends of the cell, ensuring the proper distribution of genetic material to the daughter cells.