Chemistry Of Life Quiz 3
This quiz will help you check your understanding of vocabulary and concepts needed for Unit 2 of the MCPS Biology course.
Questions and Answers
- 1.
Which of the following is NOT a good source for carbohydrates?
- A.
Olive oil
- B.
Spaghetti
- C.
Cereal
- D.
Banana
Correct Answer
A. Olive oilExplanation
Olive oil is not a good source of carbohydrates because it is a type of fat, not a carbohydrate. Carbohydrates are found in foods like spaghetti, cereal, and bananas, which are all good sources of this macronutrient. Olive oil, on the other hand, is primarily composed of monounsaturated fats and does not contain significant amounts of carbohydrates.Rate this question:
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- 2.
Which group contains ONLY monomers?
- A.
carbohydrates, proteins, nucleic acids
- B.
Cereal, table sugar, cellulose
- C.
monosaccharide, amino acid, nucleiotide
- D.
Carbon, hydrogen, oxygen, nitrogen
Correct Answer
C. monosaccharide, amino acid, nucleiotideExplanation
The group that contains ONLY monomers is monosaccharide, amino acid, nucleotide. Monosaccharides are the monomers of carbohydrates, amino acids are the monomers of proteins, and nucleotides are the monomers of nucleic acids. Cereal, table sugar, and cellulose are all examples of carbohydrates, which are polymers made up of monosaccharide monomers. Carbon, hydrogen, oxygen, and nitrogen are all elements, not monomers.Rate this question:
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- 3.
Which element, found in proteins, is NOT present in carbohydrates or lipids?
- A.
Carbon
- B.
Hydrogen
- C.
Oxygen
- D.
Nitrogen
Correct Answer
D. NitrogenExplanation
Nitrogen is the element that is found in proteins but is not present in carbohydrates or lipids. Proteins are composed of amino acids, which contain nitrogen atoms in their chemical structure. Carbohydrates and lipids, on the other hand, are primarily composed of carbon, hydrogen, and oxygen atoms, but do not contain nitrogen. Therefore, nitrogen is the correct answer.Rate this question:
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- 4.
What statement about proteins, lipids, nucleic acids, and carbohydrates is NOT true?
- A.
They are all organic.
- B.
They all contain carbon.
- C.
They all contain nitrogen.
- D.
They are found in living things.
Correct Answer
C. They all contain nitrogen.Explanation
Proteins, lipids, nucleic acids, and carbohydrates are all organic compounds because they contain carbon. However, the statement that they all contain nitrogen is not true. While proteins and nucleic acids contain nitrogen, lipids and carbohydrates do not necessarily contain nitrogen. Therefore, the correct answer is "They all contain nitrogen."Rate this question:
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- 5.
Which of the following is a major component of cell membranes?
- A.
Carbohydrate
- B.
Lipids
- C.
Proteins
Correct Answer
B. LipidsExplanation
Lipids are a major component of cell membranes. They form a bilayer structure that surrounds the cell and acts as a barrier, regulating the movement of substances in and out of the cell. Lipids, specifically phospholipids, have a hydrophilic (water-loving) head and a hydrophobic (water-fearing) tail, which allows them to arrange themselves in a way that shields the cell from the surrounding environment. This lipid bilayer provides structural support and plays a crucial role in maintaining the integrity and functionality of the cell membrane.Rate this question:
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- 6.
Starch belongs to which group of macromolecules?
- A.
Protein
- B.
Vitamin
- C.
Carbohydrate
Correct Answer
C. CarbohydrateExplanation
Starch belongs to the group of macromolecules known as carbohydrates. Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen, and they serve as a major source of energy in the human diet. Starch is a complex carbohydrate that is found in plants and serves as a storage form of energy. It is composed of long chains of glucose molecules, making it an important source of energy for both plants and animals.Rate this question:
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- 7.
Animals use _________ for long-term energy storage.
- A.
Lipids
- B.
Carbohydrates
- C.
Proteins
Correct Answer
A. LipidsExplanation
Animals use lipids for long-term energy storage. Lipids, such as fats and oils, are highly efficient molecules for storing energy because they contain more than twice the amount of energy per gram compared to carbohydrates and proteins. This makes lipids an ideal energy source for animals during times when food is scarce or when they need to sustain energy over long periods, such as during hibernation or migration. Lipids also provide insulation and protection for vital organs in animals.Rate this question:
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- 8.
Which of the following is an example of a nucleic acid?
- A.
Amino acid
- B.
Phosphate
- C.
DNA
Correct Answer
C. DNAExplanation
DNA is an example of a nucleic acid. Nucleic acids are macromolecules that store and transmit genetic information in living organisms. DNA, or deoxyribonucleic acid, is a double-stranded molecule that carries the genetic instructions for the development, functioning, growth, and reproduction of all known organisms. It is composed of nucleotide units, which consist of a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base (adenine, guanine, cytosine, or thymine). DNA is found in the nucleus of cells and plays a crucial role in the inheritance of traits from one generation to the next.Rate this question:
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- 9.
Which of the following is an example of a nucleic acid?
- A.
Amino acid
- B.
Phosphate
- C.
DNA
Correct Answer
C. DNAExplanation
DNA is an example of a nucleic acid because it is a long chain molecule made up of nucleotides. Nucleic acids are responsible for storing and transmitting genetic information in living organisms. DNA, or deoxyribonucleic acid, is found in the nucleus of cells and carries the genetic instructions for the development, functioning, and reproduction of all known living organisms. It is composed of two strands of nucleotides that are twisted together in a double helix structure. DNA is essential for the inheritance of traits from parents to offspring and plays a crucial role in the processes of protein synthesis and gene expression.Rate this question:
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- 10.
Water is used as a control in experiments to test for the presence of various organic compounds. The reason for this is that ________________.
- A.
Water is inexpensive and therefore it is easy to use
- B.
Water is an excellent solvent and soak up all of the chemicals that are used.
- C.
Water is NOT an organic molecule and therefore it is good to use for comparison.
Correct Answer
C. Water is NOT an organic molecule and therefore it is good to use for comparison.Explanation
Water is used as a control in experiments to test for the presence of various organic compounds because it is not an organic molecule. This allows researchers to compare the results of their experiments with water to those of the organic compounds being tested. Using water as a control ensures that any observed changes or reactions are specific to the organic compounds being studied and not influenced by the properties of water itself.Rate this question:
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- 11.
DNA and RNA are examples of __________.
- A.
Polysaccharides
- B.
Amino acids
- C.
Proteins
- D.
Nucleic acids
Correct Answer
D. Nucleic acidsExplanation
DNA and RNA are examples of nucleic acids because they are large biomolecules that are essential for storing and transmitting genetic information in living organisms. Nucleic acids are made up of nucleotides, which are composed of a sugar molecule, a phosphate group, and a nitrogenous base. DNA and RNA both have a sugar-phosphate backbone and contain different nitrogenous bases. DNA carries the genetic instructions for the development and functioning of all living organisms, while RNA plays a crucial role in protein synthesis.Rate this question:
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- 12.
If the left side of the beaker were hypertonic compared to the right side, what would happen to the level of water on both sides?
- A.
The left side would go up and the right side would go down.
- B.
The right side would go up and the left side would go down.
- C.
The level of water on both sides of the beaker would stay the same.
Correct Answer
A. The left side would go up and the right side would go down.Explanation
If the left side of the beaker is hypertonic compared to the right side, it means that the left side has a higher concentration of solutes. In osmosis, water moves from an area of lower solute concentration to an area of higher solute concentration. Therefore, water would move from the right side (which has lower solute concentration) to the left side (which has higher solute concentration). This would cause the level of water on the left side to go up, while the level of water on the right side would go down.Rate this question:
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- 13.
If the concentration of solute is the same both inside a cell and in the solution it's placed into, then the solution is said to be _____________.
- A.
Hypertonic
- B.
Hypotonic
- C.
Isotonic
Correct Answer
C. IsotonicExplanation
If the concentration of solute is the same both inside a cell and in the solution it's placed into, then the solution is said to be isotonic. In an isotonic solution, there is no net movement of water molecules across the cell membrane, as the concentration of solute is equal on both sides. This means that the cell will neither gain nor lose water, resulting in no change in cell volume.Rate this question:
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- 14.
A fish that is accustomed to living in salt water is placed in fresh water. What do you predict might happen to the cells of the fish?
- A.
They might shrink up and cause the fish to die.
- B.
They would become healthier because the water is so fresh.
- C.
They might burst and cause the fish to die.
Correct Answer
C. They might burst and cause the fish to die.Explanation
When a fish that is accustomed to living in saltwater is placed in freshwater, it will experience a process known as osmosis. Osmosis is the movement of water molecules from an area of lower solute concentration to an area of higher solute concentration through a semipermeable membrane. In this case, the fish's cells have adapted to life in saltwater and have a higher concentration of solutes compared to freshwater. As a result, water from the fish's cells will move outwards in an attempt to balance the concentration on both sides of the membrane. This can cause the cells to shrink and potentially burst, leading to the death of the fish.Rate this question:
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- 15.
A piece of potato is placed in pure water. The potato cells are not 100% water. Relative to the potato cells, the pure water is ___________.
- A.
Isotonic
- B.
Hypertonic
- C.
Hypotonic
Correct Answer
C. HypotonicExplanation
Since it's 100% water, it has NO solutes at all.Rate this question:
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- 16.
A cell is placed in a hypertonic solution. This means that the percentage of water is ___.
- A.
Greater in the solution.
- B.
Greater in the cell
- C.
The same in the cell and the solution.
Correct Answer
B. Greater in the cellExplanation
Hypertonic solution - more solute, less water than the cell. Therefore the cell has a greater concentration of water.Rate this question:
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- 17.
A cell that is 95% water is placed inside a solution that is 100% water. What will happen?
- A.
The cell will swell because water will enter it.
- B.
The cell will swell because it will produce more sugar.
- C.
The cell will shrink because it has less water than the solution.
Correct Answer
A. The cell will swell because water will enter it.Explanation
When a cell that is 95% water is placed in a solution that is 100% water, water will move from an area of higher concentration (the solution) to an area of lower concentration (the cell). This process is known as osmosis. As a result, the cell will absorb more water and swell. Therefore, the correct answer is that the cell will swell because water will enter it.Rate this question:
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- 18.
The process in which energy is released for use by the cell is called ______. (Be careful!!)
- A.
The mitochondrion
- B.
Respiration
- C.
The chloroplast
- D.
Photosynthesis
Correct Answer
B. RespirationExplanation
Respiration is the correct answer because it is the process by which energy is released for use by the cell. This process occurs in the mitochondria of the cell, where glucose and oxygen are broken down to produce ATP, the energy currency of the cell. The mitochondria are responsible for converting the chemical energy stored in food molecules into a form that the cell can use. This process is different from photosynthesis, which is the process by which plants convert sunlight into chemical energy. The chloroplast is the organelle responsible for photosynthesis in plant cells.Rate this question:
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- 19.
The cell wall of a plant is composed mainly of ____________.
- A.
DNA
- B.
A carbohydrate
- C.
A thin layer of phospholipid molecules
- D.
Nucleic acids
Correct Answer
B. A carbohydrateExplanation
The cell wall of a plant is composed mainly of a carbohydrate. This is because the cell wall provides structural support and protection for the plant cell, and carbohydrates such as cellulose are the primary component of the cell wall. Cellulose is a complex carbohydrate made up of repeating glucose units, which form a strong and rigid structure. Therefore, a carbohydrate is the main component of the plant cell wall.Rate this question:
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- 20.
The carbohydrate which make up the cell wall is mainly _______.
- A.
Cellulose
- B.
Glucose
- C.
Fructose
- D.
Disaccharide
Correct Answer
A. CelluloseExplanation
Cellulose is the correct answer because it is the main carbohydrate that makes up the cell wall. Cellulose is a polysaccharide composed of glucose molecules linked together, forming a strong and rigid structure. It provides support and protection to plant cells, giving them their shape and preventing them from bursting under osmotic pressure. Glucose and fructose are monosaccharides, while a disaccharide is composed of two sugar molecules. Therefore, cellulose is the most appropriate carbohydrate for forming the cell wall.Rate this question:
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