1.
Smooth muscle is an example of a(n) ______ in the human body.
Correct Answer
C. Tissue
Explanation
Smooth muscle is an example of a tissue in the human body. Tissues are groups of specialized cells that work together to perform a specific function. Smooth muscle tissue is found in the walls of organs and structures like the digestive tract, blood vessels, and respiratory system. It is responsible for involuntary movements and contractions, allowing these organs to function properly.
2.
Neurons are considered to be ______ tissue.
Correct Answer
E. Nervous
Explanation
Neurons are considered to be nervous tissue because they are the primary functional units of the nervous system. Neurons are specialized cells that transmit electrical and chemical signals throughout the body, allowing for communication between different parts of the body and the brain. Nervous tissue is responsible for processing and transmitting information, coordinating body functions, and enabling sensory perception, making it the correct classification for neurons.
3.
Which of the following tissue types is found in the stomach?
Correct Answer
E. All of the above tissues are found in the stomach
Explanation
All of the above tissues are found in the stomach because the stomach is a complex organ that performs various functions. Connective tissue provides support and structure to the stomach, epithelial tissue lines the inner surface of the stomach and helps with absorption and secretion, muscle tissue allows for the contraction and movement of the stomach, and nervous tissue enables communication and control of the stomach's functions. Therefore, all of these tissue types are present in the stomach.
4.
Production and release of hormones is the main function of the __________ system.
Correct Answer
C. Endocrine
Explanation
The endocrine system is responsible for the production and release of hormones. Hormones are chemical messengers that regulate various bodily functions and processes, such as growth, metabolism, sexual development, and mood. The endocrine system includes glands such as the pituitary gland, thyroid gland, adrenal glands, and reproductive glands. These glands secrete hormones directly into the bloodstream, where they are transported to target cells or organs to exert their effects. Therefore, the endocrine system is vital for maintaining overall homeostasis and coordinating the activities of different body systems.
5.
Plasma is:
Correct Answer
C. Extracellular fluid that is within the circulatory system.
Explanation
Plasma is the extracellular fluid that is within the circulatory system. It is the liquid component of blood that carries various substances such as nutrients, hormones, and waste products throughout the body. It is distinct from intracellular fluid, which is found inside cells, and interstitial fluid, which surrounds tissue cells. Plasma is mainly composed of water, electrolytes, proteins, and other molecules necessary for maintaining homeostasis and supporting bodily functions.
6.
The hormone glucagon causes the release of of glucose (sugar) from body cells into the bloodstream. Its secretion is controlled by a negative-feedback system between the concentration of glucose in the blood and the glucagon-secreting cells in the pancreas. Therefore, which of the following statements is correct?
Correct Answer
C. A decrease in blood glucose concentration stimulates glucagon secretion, which in turn increases the blood glucose concentration.
Explanation
A decrease in blood glucose concentration stimulates glucagon secretion, which in turn increases the blood glucose concentration. This is because when blood glucose levels are low, the pancreas releases glucagon, which signals the liver to break down glycogen into glucose and release it into the bloodstream. This raises blood glucose levels back to normal.
7.
Which of the following is an example of negative feedback?
Correct Answer
E. All of the above are examples of negative feedback.
Explanation
All of the given scenarios describe negative feedback mechanisms. In each case, a change in a particular physiological parameter (body temperature, blood pressure, blood osmolarity) is detected by specific receptors (thermoreceptors, baroreceptors, osmoreceptors) and signals are sent to the brain. The brain then initiates a series of responses that counteract the initial change and bring the parameter back to its normal range. This process helps maintain homeostasis in the body by regulating various physiological processes.
8.
The nucleus:
Correct Answer
E. All of the above
Explanation
The correct answer is "all of the above". The nucleus is enclosed in a double-layered nuclear envelope, which separates it from the cytoplasm. It contains our genetic code or DNA, which carries the instructions for protein synthesis and cell replication. Additionally, the nucleus is the site of ribosome assembly, where ribosomes, the cellular structures responsible for protein synthesis, are formed. Therefore, all of the given statements are true regarding the nucleus.
9.
Which of the following statements is False about the plasma membrane.
Correct Answer
D. Plasma membranes are only permeable to hydropHilic substances like sodium.
Explanation
Plasma membranes are not only permeable to hydrophilic substances like sodium, but they are also permeable to hydrophobic substances like oxygen. The phospholipid bilayers that make up the plasma membrane have hydrophilic heads and hydrophobic tails, creating a selectively permeable barrier that allows for the passage of both types of substances.
10.
The ________ is an organelle that contains ribosomes and is the site of synthesis of secretory proteins.
Correct Answer
A. Rough ER
Explanation
The rough ER is an organelle that contains ribosomes and is responsible for the synthesis of secretory proteins. The ribosomes on the rough ER's surface allow for the attachment of mRNA, which is then translated into proteins. These proteins are then modified and packaged for secretion or transport to other parts of the cell. The rough ER plays a crucial role in protein synthesis and secretion within the cell.
11.
For protein synthesis messenger or mRNA
Correct Answer
A. Codes for a new amino acid every three nucleotides.
Explanation
Messenger RNA (mRNA) is responsible for carrying the genetic information from the DNA to the ribosomes during protein synthesis. It acts as a template for protein synthesis by coding for a new amino acid every three nucleotides. This process is known as the genetic code, where each set of three nucleotides, called a codon, corresponds to a specific amino acid. Therefore, the correct answer is that mRNA codes for a new amino acid every three nucleotides.
12.
For protein synthesis Ribosomes:
Correct Answer
C. Catalyze the formation of peptide bonds between the amino acids.
Explanation
Ribosomes are cellular structures responsible for protein synthesis. They play a crucial role in the process of translating genetic information from RNA into a specific sequence of amino acids to form a protein.
13.
For protein synthesis transfer or tRNA:
Correct Answer
C. Catalyze the formation of peptide bonds between the amino acids.
Explanation
The correct answer is that tRNA molecules catalyze the formation of peptide bonds between amino acids. This means tRNA helps connect amino acids together to build a protein during protein synthesis.
14.
The ________ receives vesicles from the smooth endoplasmic reticulum containing proteins that need to be processed before being sent to their final destinations.
Correct Answer
E. Golgi complex
Explanation
The Golgi complex receives vesicles from the smooth endoplasmic reticulum containing proteins that need to be processed before being sent to their final destinations. The Golgi complex modifies, sorts, and packages these proteins into vesicles for transport to their appropriate locations within the cell or for secretion outside of the cell. It plays a crucial role in protein trafficking and processing within the cell.
15.
________ contain hydrolytic enzymes that break down worn out organelles and various macromolecules.
Correct Answer
B. Lysosomes
Explanation
Lysosomes contain hydrolytic enzymes that break down worn out organelles and various macromolecules. These enzymes are able to break down complex molecules such as proteins, nucleic acids, lipids, and carbohydrates into their smaller subunits. This process, known as hydrolysis, helps to recycle and eliminate cellular waste materials, ensuring the proper functioning and maintenance of the cell. Lysosomes also play a role in the digestion of engulfed foreign particles, such as bacteria or cellular debris, through a process called phagocytosis.
16.
The ________________ is where the majority of ATP is made in the cell.
Correct Answer
D. Mitochondria
Explanation
Mitochondria are known as the powerhouses of the cell because they are responsible for producing the majority of ATP, which is the main source of energy for cellular processes. They have a highly specialized structure and contain enzymes and proteins that are involved in the process of cellular respiration. Through a series of chemical reactions, mitochondria convert nutrients into ATP, which can be used by the cell to carry out various functions. Therefore, the correct answer is mitochondria.
17.
_______ are ropelike permanent cytoskeleton elements that help anchor organelles.
Correct Answer
D. Intermediate filaments
Explanation
Intermediate filaments are ropelike permanent cytoskeleton elements that help anchor organelles. They are a type of structural protein that provide mechanical support and strength to cells. Unlike microtubules and microfilaments, intermediate filaments are more stable and less dynamic. They play a crucial role in maintaining cell shape and integrity, as well as organizing the internal structure of the cell. Tubulin is a protein that makes up microtubules, while microfilaments are composed of actin. Intermediate filigrees is not a recognized term in cell biology.
18.
______ are adhering cell junctions found in tissues that undergo a lot of stretching, _____ are impermeable cell junctions frequently found in epithelial tissue, and ______ are communicating cell junctions found between cardiomyocytes in the heart.
Correct Answer
B. Desmosomes : tight junctions : gap junctions
Explanation
Desmosomes are adhering cell junctions found in tissues that undergo a lot of stretching, such as skin or muscle tissue. Tight junctions are impermeable cell junctions frequently found in epithelial tissue, where they form a barrier that prevents substances from passing between cells. Gap junctions are communicating cell junctions found between cardiomyocytes in the heart, allowing for the rapid transmission of electrical signals between cells.
19.
______ are the functional groups found on carbohydrates that make carbohydrates polar.
Correct Answer
D. Hydroxyl
Explanation
Hydroxyl groups (-OH) are the functional groups found on carbohydrates that make them polar. These groups contain an oxygen atom bonded to a hydrogen atom, resulting in a polar covalent bond. The electronegativity difference between oxygen and hydrogen creates a partial negative charge on the oxygen atom and a partial positive charge on the hydrogen atom. This polarity allows carbohydrates to form hydrogen bonds with other polar molecules, such as water, making them soluble in water and important for various biological functions.
20.
The breaking of a triglyceride into glycerol and three fatty acids is an example of a(n) __________ reaction where _______ is used and _______ is released.
Correct Answer
A. Hydrolysis : water : energy
Explanation
The breaking of a triglyceride into glycerol and three fatty acids is an example of a hydrolysis reaction because it involves the addition of water to break the bonds between the molecules. In this reaction, water is used as a reactant, and energy is released.
21.
Which of the following is a disaccharide?
Correct Answer
D. Sucrose
Explanation
Sucrose is a disaccharide because it is composed of two monosaccharides, glucose and fructose, bonded together by a glycosidic linkage. Disaccharides are a type of carbohydrate that consist of two sugar molecules joined together. Glycogen, starch, and cellulose are all polysaccharides, which are carbohydrates made up of many sugar molecules bonded together. Therefore, the correct answer is sucrose.
22.
_______ fat like vegetable oil is _______ at room temperature.
Correct Answer
C. Unsaturated : liquid
Explanation
Unsaturated fats like vegetable oil are liquid at room temperature because they have double bonds in their chemical structure. These double bonds create kinks in the fatty acid chains, preventing them from packing tightly together. As a result, unsaturated fats have a lower melting point and remain in a liquid state at room temperature.
23.
________ are hormones derived from cholesterol.
Correct Answer
D. Steroids
Explanation
Steroids are hormones derived from cholesterol. Cholesterol is a precursor molecule for the synthesis of various hormones, including steroids. Steroids are a class of hormones that play important roles in various physiological processes, such as regulating metabolism, inflammation, and reproduction. They are characterized by their structure, which includes a four-ring carbon structure derived from cholesterol. Therefore, steroids are the correct answer as they are the hormones derived from cholesterol.
24.
In the primary structure of a peptide or protein, the amino acids are held together by ________ which are a type of covalent bond.
Correct Answer
D. Peptide bonds
Explanation
In the primary structure of a peptide or protein, the amino acids are held together by peptide bonds, which are a type of covalent bond. Peptide bonds form between the carboxyl group of one amino acid and the amino group of another amino acid, resulting in the formation of a peptide chain. This covalent bond is essential for maintaining the linear sequence of amino acids in the protein or peptide, which ultimately determines its overall structure and function.
25.
When a protein denatures:
Correct Answer
C. The protein unfolds losing its quaternary and tertiary structure.
Explanation
When a protein denatures, it loses its quaternary and tertiary structure. This means that the protein unfolds and the bonds holding the different subunits together and the bonds within the protein itself are disrupted. As a result, the protein loses its functional shape and can no longer perform its biological function. Therefore, the correct answer is that the protein unfolds losing its quaternary and tertiary structure.
26.
Enzymes:
Correct Answer
D. Decrease the amount of energy needed for a chemical reaction to occur.
Explanation
Enzymes are biological catalysts that speed up chemical reactions by decreasing the amount of energy required for the reaction to occur. They achieve this by lowering the activation energy, which is the energy needed to initiate the reaction. Enzymes accomplish this by binding to the reactant molecules, bringing them closer together and facilitating the formation of new bonds or the breaking of existing bonds. This allows the reaction to proceed more quickly and efficiently. Therefore, the correct answer is that enzymes decrease the amount of energy needed for a chemical reaction to occur.
27.
Glycolysis occurs in the _______ and ______ require oxygen.
Correct Answer
D. Cytosol : does not
Explanation
Glycolysis is the process of breaking down glucose into pyruvate in the cytosol of the cell. It is the first step in cellular respiration and does not require oxygen. Therefore, the correct answer is "cytosol: does not".
28.
If enough oxygen is not available our cells will convert _______ to ______ in order to regenerate __________.
Correct Answer
C. Pyruvate : lactate : NAD
Explanation
When there is not enough oxygen available, our cells undergo a process called anaerobic respiration. In this process, pyruvate, which is the end product of glycolysis, is converted to lactate. This conversion allows the regeneration of NAD, which is needed for glycolysis to continue producing ATP in the absence of oxygen. Therefore, the correct answer is pyruvate : lactate : NAD.
29.
The krebs cycle occurs in the _______.
Correct Answer
D. Mitochondrial matrix
Explanation
The Krebs cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the mitochondria. Specifically, it takes place in the mitochondrial matrix, which is the innermost compartment of the mitochondria. This is where the enzymes and molecules involved in the cycle are located. The Krebs cycle plays a crucial role in cellular respiration by generating energy-rich molecules that are utilized in the production of ATP. Therefore, the correct answer is mitochondrial matrix.
30.
______ is terminal electron acceptor in the electron transport chain and when it accepts electrons becomes _______.
Correct Answer
B. Oxygen : water
Explanation
In the electron transport chain, oxygen serves as the terminal electron acceptor. When oxygen accepts electrons, it combines with hydrogen ions to form water. This process is essential for the production of ATP, the energy currency of the cell.
31.
_________ is the transmembrane protein found on the inner mitochondrial membrane that allows protons into the _______ from the ______ in order to provide the energy needed to make ATP from ADP.
Correct Answer
C. ATP synthase : matrix : intermembrane space
Explanation
ATP synthase is the transmembrane protein found on the inner mitochondrial membrane that allows protons into the matrix from the intermembrane space in order to provide the energy needed to make ATP from ADP.
32.
The brain can use which type(s) of molecules to make ATP?
Correct Answer
A. Glucose
Explanation
Glucose is the correct answer because it is the primary source of energy for the brain. The brain can use glucose molecules to produce ATP through the process of glycolysis and subsequent steps in cellular respiration. While fatty acids and amino acids can also be used as alternative energy sources, glucose is the preferred substrate for ATP production in the brain. Therefore, the brain can use glucose molecules to make ATP.
33.
The making of glucose from noncarbohydrate precursors like amino acids or glycerol is called:
Correct Answer
C. Gluconeogenesis
Explanation
Gluconeogenesis is the process of synthesizing glucose from noncarbohydrate precursors such as amino acids or glycerol. It is an important metabolic pathway that occurs mainly in the liver and kidneys. During times of low glucose availability, gluconeogenesis helps maintain blood glucose levels by producing glucose from alternative sources. This process is essential for supplying glucose to the brain, red blood cells, and other glucose-dependent tissues. Glycogenolysis, on the other hand, is the breakdown of glycogen into glucose, while glycolysis is the breakdown of glucose into pyruvate. Glycogen synthesis involves the formation of glycogen from glucose molecules, and peptide synthesis refers to the formation of peptides from amino acids.
34.
Plasma membranes are made up of lipid bilayers that spontaneously form due to the amphipathic nature of ________.
Correct Answer
C. pHospHolipids
Explanation
The correct answer is phospholipids because they have both hydrophilic and hydrophobic regions. This amphipathic nature allows them to spontaneously form lipid bilayers, which make up the plasma membrane. Cholesterol, triglycerides, ATP, and cytoskeleton do not have the same amphipathic properties as phospholipids and therefore cannot form lipid bilayers.
35.
Proteins in or associated with the plasma membrane:
Correct Answer
E. All of the above.
Explanation
Proteins in or associated with the plasma membrane can serve as receptors, allowing the cell to respond to signals from the environment. They can also act as membrane-bound enzymes, catalyzing reactions on the cell surface. Additionally, these proteins can function as channels, allowing the selective passage of ions and molecules across the membrane. Finally, they may serve as cell adhesion molecules, helping cells adhere to each other and to the extracellular matrix. Therefore, all of the given options are correct, as proteins in or associated with the plasma membrane can perform all of these functions.
36.
The anions that give the interior of cells their negative charge are ______?
Correct Answer
C. Proteins
Explanation
Proteins give the interior of cells their negative charge because they contain negatively charged amino acids. These amino acids have side chains that can ionize and release hydrogen ions, resulting in a negative charge. Additionally, proteins are involved in various cellular processes and play a crucial role in maintaining the overall charge balance within cells. Sodium and potassium ions, on the other hand, are positively charged and contribute to the overall positive charge of the cell exterior. Carbohydrates and lipids do not play a significant role in determining the negative charge of the cell interior.
37.
Potassium:
Correct Answer
E. Both (b) and (c)
Explanation
Potassium ions (K+) are positively charged and are found in higher concentration inside the cell compared to outside. Therefore, the correct answer is both (b) and (c).
38.
Sodium:
Correct Answer
B. Is positively charged
Explanation
Sodium is positively charged because it is an ion with a positive charge. It has lost one electron, resulting in a positive charge. Additionally, sodium is also in higher concentration inside the cell, which is another characteristic of sodium. Therefore, the correct answer is "both (b) and (c)".
39.
Potassium’s electrical gradient:
Correct Answer
A. Opposes its chemical gradient.
Explanation
The electrical gradient of potassium opposes its chemical gradient. This means that the movement of potassium ions across the cell membrane is driven by both the concentration gradient and the electrical potential difference. However, in this case, the electrical gradient acts in the opposite direction to the chemical gradient, causing potassium ions to move against their concentration gradient and potentially leave the cell.
40.
At rest cells:
Correct Answer
C. Have less sodium in their intracellular fluid than the extracellular fluid.
Explanation
At rest, cells have less sodium in their intracellular fluid than the extracellular fluid. This is because the cell membrane contains sodium-potassium pumps that actively transport sodium out of the cell and potassium into the cell, resulting in a higher concentration of potassium inside the cell and a lower concentration of sodium inside the cell compared to the extracellular fluid. This difference in ion concentrations creates an electrochemical gradient that is important for various cellular processes, including the transmission of nerve impulses.
41.
Which of the following substances is MOST likely to passively diffuse across the plasma membrane by dissolving in the membrane?
Correct Answer
C. A nonpolar molecule like oxygen
Explanation
Nonpolar molecules, such as oxygen, are most likely to passively diffuse across the plasma membrane by dissolving in the membrane. This is because the plasma membrane is composed of a phospholipid bilayer, which is made up of hydrophobic tails that repel polar molecules. Nonpolar molecules can easily dissolve in the hydrophobic region of the membrane and diffuse across it without the need for any energy or assistance from transport proteins.
42.
Increasing the ________ would decrease the diffusion rate of oxygen.
Correct Answer
D. Diffusion distance
Explanation
Increasing the diffusion distance would decrease the diffusion rate of oxygen because a greater distance that the oxygen molecules have to travel would slow down the rate at which they can diffuse across the membrane. As the distance increases, it becomes more difficult for the oxygen molecules to move from an area of high concentration to an area of low concentration, resulting in a slower diffusion rate.
43.
The process of water diffusing down its concentration gradient is called:
Correct Answer
C. Osmosis
Explanation
Osmosis is the process of water diffusing down its concentration gradient. It occurs when water molecules move from an area of higher water concentration (lower solute concentration) to an area of lower water concentration (higher solute concentration) through a selectively permeable membrane. This movement of water helps to equalize the concentration of solutes on both sides of the membrane. Osmosis is a passive process and does not require energy expenditure by the cell.
44.
A(n) ______ solution would make your red blood cells shrink.
Correct Answer
B. Hypertonic
Explanation
A hypertonic solution has a higher concentration of solutes compared to the red blood cells. When red blood cells are placed in a hypertonic solution, water molecules move out of the cells through osmosis, causing the cells to shrink.
45.
The concentration of glucose in enterocytes (epithelial cells lining the small intestine) is higher than the concentration of glucose in the blood stream. Glucose is transported by ________ when it is transported into the bloodstream from enterocytes.
Correct Answer
C. Facilitated diffusion
Explanation
Facilitated diffusion is the process by which molecules, such as glucose, are transported across a cell membrane with the help of transport proteins. In this case, the concentration of glucose is higher in the enterocytes than in the blood stream, suggesting that glucose needs to move from an area of higher concentration to an area of lower concentration. Facilitated diffusion allows glucose to passively move down its concentration gradient, from the enterocytes into the bloodstream, without requiring energy input.
46.
The sodium potassium pump or ATPase that pumps 3 sodium out of the cell for every 2 potassium it pumps in is a form of:
Correct Answer
A. Primary active transport.
Explanation
The sodium-potassium pump is a form of primary active transport because it uses ATP energy to actively transport ions against their concentration gradient. It pumps 3 sodium ions out of the cell for every 2 potassium ions it pumps in, maintaining the concentration gradient and electrical potential across the cell membrane. This process requires energy and is essential for various cellular functions, such as nerve impulses and muscle contractions.
47.
The concentration of glucose in the lumen of the intestine is lower than the concentration of glucose in the enterocytes (epithelial cells lining the small intestine), if the sodium potassium pump is inhibited by the drug phloridzin then no glucose is absorbed into the enterocytes. Therefore glucose is transported by ________ when it is absorbed into enterocytes from the intestine.
Correct Answer
B. Secondary active transport
Explanation
When the sodium potassium pump is inhibited, the concentration of sodium inside the enterocytes increases. This creates a concentration gradient, as the concentration of sodium is now higher inside the enterocytes compared to the lumen of the intestine. Glucose is then transported into the enterocytes against its concentration gradient, utilizing the energy from the sodium concentration gradient. This type of transport, where the movement of one molecule is coupled to the movement of another molecule down its concentration gradient, is known as secondary active transport. Therefore, glucose is transported by secondary active transport when it is absorbed into enterocytes from the intestine.
48.
Vesicular transport is the process by which cells bring in or release large amounts of solutes or large particles. Which of the following is the vesicular transport method that neurons use to release large amounts of neurotransmitters at once?
Correct Answer
A. Exocytosis
Explanation
Exocytosis is the correct answer because it is the vesicular transport method that neurons use to release large amounts of neurotransmitters at once. In exocytosis, neurotransmitter-containing vesicles fuse with the cell membrane and release their contents into the extracellular space. This allows for the rapid and efficient release of neurotransmitters, which are essential for communication between neurons. Phagocytosis and pinocytosis are processes by which cells internalize solid particles and fluids, respectively, and are not specific to neurotransmitter release. Receptor-mediated endocytosis and receptor-mediated exocytosis involve the specific binding of ligands to cell surface receptors, but they are not the primary mechanisms for neurotransmitter release in neurons.
49.
Vesicular transport is the process by which cells bring in or release large amounts of solutes or large particles. Which of the following is the vesicular transport method that white blood cells would use to engulf a bacterial cell?
Correct Answer
B. pHagocytosis
Explanation
White blood cells use phagocytosis to engulf and destroy bacterial cells. Phagocytosis is a type of vesicular transport where the cell membrane surrounds and engulfs the particle or microorganism, forming a phagosome. The phagosome then fuses with lysosomes, which contain enzymes that can break down the engulfed material. This process allows white blood cells to eliminate pathogens and foreign particles from the body.
50.
This exam:
Correct Answer
B. Was just right
Explanation
The exam being described as "just right" suggests that it was neither too difficult nor too easy. It implies that the level of difficulty was appropriate and balanced, allowing the test takers to demonstrate their knowledge and skills effectively.