1.
What is non polar covalent bonds?
Correct Answer
B. Have electrons that are equally distributed between two identical atoms
Explanation
Nonpolar covalent bonds occur when two identical atoms share electrons equally. In this type of bond, the electron density is evenly distributed between the two atoms, resulting in a balanced sharing of electrons. This means that neither atom has a stronger pull on the electrons, leading to a symmetrical distribution of charge. As a result, nonpolar covalent bonds do not have a partial positive or negative charge on either atom.
2.
6 carbon units enter this stage:
Correct Answer
B. Glycolysis
Explanation
Glycolysis is the correct answer because it is the initial stage of cellular respiration where glucose is broken down into two molecules of pyruvate, each containing three carbon units. This process occurs in the cytoplasm and does not require oxygen. The pyruvate molecules produced in glycolysis then enter the mitochondria to undergo further oxidation in the Krebs Cycle, where they are converted into acetyl CoA. Finally, the acetyl CoA molecules enter the Electron Transport Chain, which takes place in the inner mitochondrial membrane, to produce ATP through oxidative phosphorylation.
3.
The most ATP comes from this stage:
Correct Answer
C. Electron Transport Chain
Explanation
The electron transport chain is the stage in cellular respiration that produces the most ATP. During this process, electrons from NADH and FADH2 are passed along a series of protein complexes, generating a proton gradient across the inner mitochondrial membrane. This gradient is then used by ATP synthase to produce ATP. Compared to glycolysis and the Krebs cycle, which produce a smaller amount of ATP, the electron transport chain is the final step in respiration and is responsible for the majority of ATP production.
4.
H+ are moved , creating a concentration gradient that drives ATP synthesis here:
Correct Answer
C. Electron Transport Chain
Explanation
In the electron transport chain, H+ ions are moved across the inner mitochondrial membrane, creating a concentration gradient. This gradient is used by ATP synthase to generate ATP through a process called oxidative phosphorylation. As the H+ ions flow back into the mitochondrial matrix through ATP synthase, the energy released is used to convert ADP to ATP. Therefore, the movement of H+ ions in the electron transport chain creates a concentration gradient that drives ATP synthesis.
5.
Sugars are burned either aerobically or anaerobically here:
Correct Answer
A. Glycolysis
Explanation
Glycolysis is the first step in cellular respiration, where glucose is broken down into pyruvate. It can occur both aerobically (in the presence of oxygen) and anaerobically (in the absence of oxygen). In aerobic conditions, pyruvate is further oxidized in the Krebs Cycle and electron transport chain to produce ATP. In anaerobic conditions, pyruvate is converted into lactate or ethanol, yielding a small amount of ATP. Therefore, glycolysis can occur in both aerobic and anaerobic conditions, making it the correct answer.
6.
The most CO2 comes from this stage:
Correct Answer
B. Krebs Cycle
Explanation
The Krebs Cycle is the stage in cellular respiration where the majority of carbon dioxide (CO2) is produced. This cycle occurs in the mitochondria and is responsible for breaking down glucose and producing energy. During the Krebs Cycle, carbon atoms from glucose are released as CO2, which is then transported to the lungs for exhalation. This process generates a large amount of CO2 compared to the other stages of cellular respiration, making the Krebs Cycle the primary source of CO2 production.
7.
Inside the Golgi Body, what do you see occuring?
Correct Answer
D. All of the above
Explanation
Inside the Golgi Body, various processes occur. Proteins are sorted into different types for different destinations, meaning they are directed to specific locations within the cell. Proteins also undergo different types of modifications, such as the addition of sugar molecules or the cutting of certain sections. Finally, the Golgi Body is responsible for packaging proteins that are finished and ready for secretion out of the cell. Therefore, all of the given options are correct and accurately describe the events that occur inside the Golgi Body.
8.
What are types of things you find inside a vesicle?
Correct Answer
C. Wastes pooled together for exocytosis
Explanation
Inside a vesicle, wastes are pooled together for exocytosis. Exocytosis is the process by which cells release waste materials or other substances to the external environment. Vesicles act as small storage compartments within cells, and they can contain various substances such as waste products that need to be eliminated from the cell. These waste materials are gathered and stored in vesicles until they are ready to be transported and released outside the cell through exocytosis. Therefore, the correct answer is "Wastes pooled together for exocytosis."
9.
What types of things would you find inside a lysosome?
Correct Answer
E. All of the above
Explanation
Inside a lysosome, you would find old membranes and proteins being broken down to recycle, incoming food being digested into smaller parts that the other organelles could accept, and wastes pooled together for exocytosis. Therefore, the correct answer is "All of the above."
10.
You need to decide what type of antibiotic to give a patient, who has an infection. To do this, you need to know if the pathogen that has been infected them is prokaryotic or eukaryotic. What do you look for under the microscope?
Correct Answer
D. The presence/absence of a nuclear membrane
Explanation
To determine whether the pathogen is prokaryotic or eukaryotic, you would look for the presence or absence of a nuclear membrane under the microscope. Prokaryotes do not have a nuclear membrane, while eukaryotes do. This is a key characteristic that helps differentiate between the two types of organisms.
11.
Uses energy and proteins to move small molecules from one side of the membrane to the other. Often moves molecules from low concentration to higher concentration.
Correct Answer
E. Active Transport
Explanation
Active transport is the correct answer because it involves the use of energy and proteins to move small molecules from one side of the membrane to the other. Unlike diffusion and osmosis, which rely on the movement of molecules from areas of high concentration to areas of low concentration, active transport moves molecules against their concentration gradient, often from low concentration to higher concentration. Filtration and dilation are not related to the movement of molecules across a membrane.
12.
Uses a concentration differences to move small molecules from one side of the membrane to the other. SOme types require protein transporters, some do not. No energy is required.
Correct Answer
A. Diffusion
Explanation
Diffusion is the correct answer because it involves the movement of small molecules from an area of high concentration to an area of low concentration, utilizing the concentration differences. It does not require energy and can occur without the need for protein transporters. Endocytosis/Phagocytosis involves the engulfing of large particles or molecules by the cell membrane, which is not mentioned in the given explanation. Active transport, on the other hand, requires energy to move molecules against their concentration gradient, which is not mentioned in the explanation either. Therefore, the correct answer is diffusion.
13.
Diffusion without protein mediation:
Correct Answer
C. Oxygen and water
Explanation
Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration. It can occur with or without protein mediation. In this case, the correct answer is "Oxygen and water" because these molecules are small and nonpolar, allowing them to diffuse freely across the cell membrane without the need for protein channels or carriers. Sodium or potassium ions and complex molecules like fatty acids require protein mediation for diffusion to occur.
14.
Protein-mediated transport:
Correct Answer
C. Sodium or Potassium ions
Explanation
Protein-mediated transport refers to the process of transporting molecules across a cell membrane with the help of specific proteins. In this case, the correct answer is Sodium or Potassium ions. This means that proteins in the cell membrane are responsible for transporting Sodium or Potassium ions across the membrane. These ions are crucial for various cellular processes such as maintaining the cell's electrical potential and regulating water balance.
15.
Endocytosis/Phagocytosis:
Correct Answer
A. Complex molecules (fatty acids)
Explanation
Endocytosis and phagocytosis are processes by which cells engulf and internalize substances from their external environment. These processes are used to take in complex molecules such as fatty acids, among other substances. Therefore, the correct answer is complex molecules (fatty acids).
16.
Each DNA strand has a backbone that consists of alternating:
Correct Answer
E. A and D
Explanation
The correct answer is A and D. This is because the backbone of each DNA strand consists of alternating sugar and phosphate molecules, which are connected by covalent bonds. The nitrogen-containing bases are attached to the sugar molecules and are connected to each other by hydrogen bonds. Therefore, both A (covalent bonds) and D (sugar and phosphate molecules) are correct.
17.
Identify the phase of mitosis which is correctly paired with its characteristics:
Correct Answer
D. PropHase- nuclear membrane disentegrates
Explanation
During prophase, the nuclear membrane disintegrates. This is the first phase of mitosis, where the chromatin condenses into visible chromosomes, and the spindle apparatus begins to form. The disintegration of the nuclear membrane allows the chromosomes to become more accessible for the subsequent steps of mitosis. It also allows the spindle fibers to interact with the chromosomes and move them during later stages of mitosis.
18.
Four of the five answers below are related by a common phase of mitosis. Find the EXCEPTION that does not apply to the same stage of mitosis.
Correct Answer
B. Division of the centromere
Explanation
The division of the centromere is not related to a specific phase of mitosis. The centromere is the region of a chromosome where the sister chromatids are held together before they separate during anaphase. The division of the centromere occurs during anaphase, which is the stage of mitosis when the sister chromatids are pulled apart to opposite ends of the cell. Therefore, the division of the centromere does not belong to the same stage of mitosis as the other options provided.
19.
Electrons are electrically neutral
Correct Answer
A. True
Explanation
Electrons are electrically neutral because they have a negative charge that is equal in magnitude to the positive charge of a proton. This means that the total charge of an electron is zero, making it electrically neutral.
20.
Atoms do not carry a charge
Correct Answer
A. True
Explanation
Atoms are composed of protons, neutrons, and electrons. Protons carry a positive charge, electrons carry a negative charge, and neutrons have no charge. In an atom, the number of protons is equal to the number of electrons, resulting in a neutral charge overall. Therefore, atoms do not carry a charge, making the statement "Atoms do not carry a charge" true.
21.
Ions are typically elements one or two electrons in excess or shortage of a stable octet
Correct Answer
A. True
Explanation
This statement is true because ions are formed when atoms gain or lose electrons to achieve a stable electron configuration, usually with eight electrons in the outermost energy level (known as an octet). Ions can either gain electrons to become negatively charged (anions) or lose electrons to become positively charged (cations). Therefore, ions typically have one or two electrons in excess or shortage of a stable octet.
22.
Negative ions are similar to positive ions in that they have an extra electron
Correct Answer
B. False
Explanation
Negative ions are not similar to positive ions because negative ions have gained an extra electron, while positive ions have lost an electron. This extra electron gives negative ions a negative charge, whereas positive ions have a positive charge. Therefore, the statement is false.
23.
Elements are like ions in that they are not stable and therefore highly reactive
Correct Answer
A. True
Explanation
Elements are like ions in that they are not stable and therefore highly reactive. This is because elements, like ions, have incomplete outer electron shells. In order to achieve stability, elements tend to gain, lose, or share electrons with other atoms, resulting in the formation of chemical bonds. This reactivity is what allows elements to participate in various chemical reactions and form compounds. Therefore, the statement that elements are not stable and highly reactive is true.
24.
Ionic bonds result from the sharing of electrons in a pair to complete an octet
Correct Answer
B. False
Explanation
Ionic bonds actually result from the transfer of electrons, not the sharing of electrons. In an ionic bond, one atom donates electrons to another atom in order to achieve a stable electron configuration. This transfer of electrons creates charged ions that are attracted to each other, forming the ionic bond. Therefore, the statement that ionic bonds result from the sharing of electrons is incorrect.
25.
Which molecular process takes place in the Cytoplasm?
Correct Answer
B. Translation only
Explanation
Translation is the molecular process that takes place in the cytoplasm. It is the process by which the genetic information encoded in mRNA is used to synthesize proteins. During translation, ribosomes in the cytoplasm read the mRNA sequence and assemble amino acids into a polypeptide chain, which ultimately forms a protein. Replication, on the other hand, occurs in the nucleus and is the process of copying DNA to produce an identical DNA molecule. Transcription also occurs in the nucleus and is the process of synthesizing mRNA from a DNA template. Therefore, the correct answer is "Translation only" as it is the only molecular process that occurs in the cytoplasm.
26.
What molecular process takes place in the Nucleus?
Correct Answer
C. Transcription only
Explanation
Transcription is the process by which genetic information in DNA is copied into a complementary RNA molecule. This process occurs in the nucleus of eukaryotic cells, where DNA is located. During transcription, RNA polymerase enzyme binds to a specific region of DNA called the promoter and synthesizes a strand of RNA that is complementary to the DNA template strand. This RNA molecule, known as messenger RNA (mRNA), carries the genetic information from the nucleus to the cytoplasm, where it is then translated into a protein through the process of translation. Therefore, the correct answer is transcription only.
27.
This process generates two cells that are alike
Correct Answer
D. A and C
Explanation
Mitosis is a cell division process where a single cell divides into two identical daughter cells. It is a form of asexual reproduction and occurs in somatic cells for growth and repair. Meiosis, on the other hand, is a cell division process that occurs in reproductive cells (gametes) and results in the formation of four non-identical daughter cells. Therefore, the correct answer is A and C, as both Mitosis and Meiosis II generate two cells that are alike.
28.
This process generates two cells with 46 chromosomes
Correct Answer
A. Mitosis
Explanation
Mitosis is the correct answer because it is the process of cell division that results in the formation of two identical daughter cells, each with the same number of chromosomes as the parent cell. In mitosis, the parent cell's chromosomes are replicated and divided equally between the two daughter cells, resulting in each daughter cell having the same number of chromosomes as the parent cell. Therefore, this process generates two cells with 46 chromosomes. Meiosis I and Meiosis II involve two rounds of cell division, resulting in the formation of four daughter cells with half the number of chromosomes as the parent cell.
29.
This process generates cells with 23 chromosomes
Correct Answer
E. B and C
Explanation
The correct answer is B and C because both Meiosis I and Meiosis II generate cells with 23 chromosomes. In Meiosis I, the cell undergoes homologous chromosome pairing and crossing over, resulting in two daughter cells with half the number of chromosomes. Then, in Meiosis II, these daughter cells undergo further division, resulting in four cells, each with 23 chromosomes.
30.
This process pairs chromosomes you received from each parent
Correct Answer
B. Meiosis I
Explanation
Meiosis I is the correct answer because it is the process that pairs chromosomes received from each parent. During Meiosis I, homologous chromosomes pair up and exchange genetic material through a process called crossing over. This ensures genetic diversity by shuffling the genetic information from both parents. Meiosis II, on the other hand, is the second division in meiosis where the sister chromatids separate, resulting in the formation of four haploid cells.
31.
Hydrolysis is the removal of water to break down a covalent bond between two compounds
Correct Answer
B. False
Explanation
Hydrolysis is actually the opposite process - it involves the addition of water to break down a covalent bond between two compounds. This reaction is commonly used in digestion, where water is added to break down complex molecules into simpler ones. Therefore, the correct answer is False.
32.
Covalent bonds are the result of equal sharing of electrons
Correct Answer
A. True
Explanation
Covalent bonds occur when two atoms share electrons equally, resulting in a strong bond between them. This sharing of electrons allows both atoms to achieve a stable electron configuration, making the statement "Covalent bonds are the result of equal sharing of electrons" true. In covalent bonds, the electrons are not transferred from one atom to another, but rather shared between the atoms involved in the bond.
33.
Hydrocarbons are lipids, fats and oils, and are hydrophobic
Correct Answer
A. True
Explanation
Hydrocarbons are organic compounds composed of only hydrogen and carbon atoms. Lipids, fats, and oils are examples of hydrocarbons as they consist mainly of carbon and hydrogen atoms. Additionally, hydrocarbons are known to be hydrophobic, meaning they do not mix or dissolve in water. Therefore, the statement that hydrocarbons are lipids, fats, and oils, and are hydrophobic is true.
34.
Carbohydrates are built when covalent bonds form between sugar monomers, releasing water
Correct Answer
A. True
Explanation
Carbohydrates are indeed built when covalent bonds form between sugar monomers, a process known as dehydration synthesis. During this process, a water molecule is released as a byproduct. This is a fundamental concept in biochemistry, where monosaccharides (sugar monomers) join together through glycosidic linkages to form larger carbohydrates such as disaccharides and polysaccharides. Therefore, the statement is true.
35.
Ionic bonds are difficult to dissolve in water
Correct Answer
B. False
Explanation
Ionic bonds are not difficult to dissolve in water. In fact, they are quite easy to dissolve in water. When an ionic compound is placed in water, the water molecules surround the ions, separating them from each other and causing the compound to dissolve. This process is known as hydration. The positive and negative charges of the ions are attracted to the polar water molecules, allowing the compound to break apart and dissolve. Therefore, the correct answer is False.
36.
Diffusion is a result of the kinetic energy in molecules
Correct Answer
A. True
Explanation
Diffusion is the process by which molecules move from an area of high concentration to an area of low concentration. This movement is driven by the kinetic energy of the molecules, as they constantly move and collide with one another. The molecules with higher kinetic energy are more likely to move and spread out, leading to diffusion. Therefore, it is correct to say that diffusion is a result of the kinetic energy in molecules.
37.
Catabolism is a process carried out in the lysosome
Correct Answer
A. True
Explanation
Catabolism is a process that involves breaking down complex molecules into simpler ones to release energy. The lysosome is a cellular organelle responsible for the breakdown of various biomolecules. It contains enzymes that can break down proteins, lipids, carbohydrates, and nucleic acids. Therefore, catabolism does occur in the lysosome, making the statement "Catabolism is a process carried out in the lysosome" true.
38.
Calcium with 20 protons and 18 electrons and 20 neutrons:
Correct Answer
A. Ion
Explanation
An ion is an atom that has gained or lost electrons, resulting in a net positive or negative charge. In this case, calcium with 20 protons and 18 electrons would have a +2 charge, indicating that it has lost 2 electrons. Therefore, the correct answer is ion.
39.
Potassium with 19 protons, 19 electrons, and 20 neutrons
Correct Answer
B. Isotope
Explanation
The given information describes an isotope of potassium. An isotope is a variant of an element that has the same number of protons but a different number of neutrons. In this case, the number of protons (19) and electrons (19) matches the atomic number of potassium, but the number of neutrons (20) is different from the usual number of neutrons for potassium. Therefore, the correct answer is isotope.
40.
Chlorine with 17 protons and 17 neutrons and 17 electrons
Correct Answer
C. Atom represented
Explanation
The given information describes the composition of an atom of chlorine, which has 17 protons, 17 neutrons, and 17 electrons. Therefore, the correct answer is "Atom represented," as it accurately represents the structure of a chlorine atom. An ion would have a different number of electrons, while an isotope would have a different number of neutrons. "None of the above" is incorrect because the given information does represent an atom.
41.
Homeostasis:
Correct Answer
C. Depends upon the interaction of receptors, integrating centers, and effectors.
Explanation
The correct answer is "Depends upon the interaction of receptors, integrating centers, and effectors." This is because homeostasis, which refers to the maintenance of a stable internal environment, relies on the coordination and interaction of receptors (which detect changes in the environment), integrating centers (which process the information received from receptors), and effectors (which carry out the necessary responses to restore balance). Positive feedback is not primarily used in homeostasis, and acclimatization refers to the process of adjusting to the external environment, which is not the main mechanism involved in homeostasis.
42.
Which of the following subatomic particles is not found within the nucleus of the atom?
Correct Answer
A. Electron
Explanation
Electrons are not found within the nucleus of the atom. Electrons are negatively charged subatomic particles that orbit the nucleus in specific energy levels or shells. The nucleus, on the other hand, contains protons and neutrons. Protons are positively charged particles, and neutrons have no charge. Therefore, the correct answer is electron.
43.
A covalent chemical bond is one in which atoms:
Correct Answer
C. Share one or more electrons
Explanation
A covalent chemical bond is formed when atoms share one or more electrons. In this type of bond, the electrons are not transferred from one atom to another, as in ionic bonds, but rather they are shared between the atoms. This sharing of electrons allows both atoms to achieve a more stable electron configuration, resulting in a strong bond between the atoms.
44.
Which of the following is not true of hydrogen bonds?
Correct Answer
D. Hydrogen bonds form between one polar and one nonpolar molecule
Explanation
Hydrogen bonds form between one polar and one nonpolar molecule. Hydrogen bonds are weak compared to covalent and ionic bonds, easily broken by raising temperature, and important in molecular interactions and contribute to the overall shape of large molecules.
45.
Proteins are:
Correct Answer
E. A and D
Explanation
Proteins are macromolecules that are critically important for physiological processes. They play a vital role in various biological functions such as cell structure, enzymatic reactions, transportation of molecules, and immune responses. Proteins are composed of subunits called amino acids, which are linked together by polypeptide bonds. Therefore, the correct answer is A and D, as proteins are both critically important for physiological processes and are macromolecules with subunits linked by polypeptide bonds.
46.
Which is not a correct description of glycolysis?
Correct Answer
A. It only occurs aerobically
Explanation
Glycolysis is the metabolic pathway that breaks down glucose into pyruvic acid. It is a universal process that occurs in both aerobic and anaerobic conditions. Therefore, the statement that "it only occurs aerobically" is incorrect. Glycolysis takes place in the cytosol of the cell and involves a series of enzymatic reactions. It also results in the net synthesis of two molecules of ATP. Glucose is indeed the primary carbohydrate metabolized in glycolysis.
47.
Which describes the process of transcription:
Correct Answer
E. B and C
Explanation
The correct answer is B and C. Transcription is the process of transferring genetic information from DNA to RNA. It occurs in the cell nucleus. This process involves the synthesis of RNA molecules using a DNA template. The DNA strand is used as a template to create a complementary RNA molecule, resulting in the transfer of genetic information. Transcription is an essential step in gene expression and allows for the production of different types of RNA molecules, including messenger RNA (mRNA) which is involved in protein synthesis.
48.
Phospholipids form effective barriers between aqueous cytosol of cells and the aqueous extracellular fluid because they are?
Correct Answer
E. A and B
Explanation
Phospholipids form effective barriers between aqueous cytosol of cells and the aqueous extracellular fluid because they are both polar and nonpolar. The polar head of the phospholipid molecule is hydrophilic, meaning it attracts water molecules, while the nonpolar tails are hydrophobic, repelling water. This dual nature allows phospholipids to arrange themselves in a bilayer, with the hydrophilic heads facing the water on both sides and the hydrophobic tails in the middle. This structure creates a barrier that prevents water and other polar molecules from freely crossing the cell membrane, maintaining the separation between the cytosol and extracellular fluid.
49.
Shivering is a response to a cold draft is an example of:
Correct Answer
D. A and B
Explanation
Shivering is a response to a cold draft, which is a mechanism to maintain homeostasis by regulating body temperature. It is also an example of negative feedback, as shivering helps to increase body heat production in response to a drop in temperature. Therefore, the correct answer is A and B.
50.
Equally distributed electrons between two atoms
Correct Answer
B. Non polar covalent
Explanation
In a non polar covalent bond, the electrons are equally distributed between two atoms. This means that the atoms have similar electronegativity, resulting in a balanced sharing of electrons. As a result, there is no significant charge separation, and the molecule is electrically neutral. Therefore, the given answer "non polar covalent" is correct.