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Question 1:
Which of the following pyrimidine bases is not found in DNA?
Topic: Pyrimidine Bases in DNA Structure
Correct Answer: D) Uracil
Detailed Hints:
- Pyrimidine bases in DNA include Cytosine, Thymine, and Uracil.
- However, Uracil is exclusive to RNA structure, not DNA.
- Adenine is not a pyrimidine base but a purine base, which is why it's not the correct choice here.
- Cytosine and Thymine are both present in DNA, making them incorrect choices as well.
- Therefore, the correct answer is D, "Uracil".
Question 2:
What type of bonds keeps the two chains of DNA interconnected?
Topic: Bonding in DNA Structure
Correct Answer: B) Hydrogen bonds
Detailed Hints:
- DNA structure consists of two chains or strands that are interconnected.
- Among the options provided, ionic and covalent bonds are strong bonds. Disulphide bonds are specific to protein structure.
- Hydrogen bonds, which are weaker and more flexible, are the ones responsible for holding the two DNA chains together.
- Therefore, the correct answer is B, "Hydrogen bonds".
Question 3:
Which three elements are the constituents of carbohydrates, the organic molecules?
Topic: Composition of Carbohydrates
Correct Answer: C) Carbon, Hydrogen and Oxygen
Detailed Hints:
- Carbohydrates are organic molecules, and they are primarily composed of three elements.
- While water, sulphur, calcium, and hydrogen are related to organic compounds, they are not the primary constituents of carbohydrates.
- The three correct elements that constitute carbohydrates are Carbon, Hydrogen, and Oxygen.
- Consequently, the correct answer is C, "Carbon, Hydrogen and Oxygen".
Question 4:
Identify the compound that doesn't belong to the monosaccharide category.
Topic: Types of Carbohydrates
Correct Answer: D) All of the above
Detailed Hints:
- Monosaccharides are the simplest form of carbohydrates.
- Sucrose, Maltose, and Lactose are not monosaccharides; they are disaccharides, which are composed of two monosaccharide molecules.
- Therefore, none of the options provided are monosaccharides.
- Hence, the correct answer is D, "All of the above".
Question 5:
What is the most abundant compound found in nature?
Topic: Abundance of Compounds in Nature
Correct Answer: A) Cellulose
Detailed Hints:
- Though the options provided are all organic compounds existing in nature, their abundances vary greatly.
- Glycerol, waxes, and starch are abundant, but not the most abundant.
- Among these compounds, Cellulose stands out as the most abundant.
- Thus, the correct answer is A, "Cellulose".
Question 6:
Steroids are categorized under which class of biomolecules?
Topic: Classification of Biomolecules
Correct Answer: B) Lipids
Detailed Hints:
- Biomolecules are broadly classified into Carbohydrates, Lipids, Proteins, and Nucleic Acids.
- Steroids do not belong to Carbohydrates, Proteins, or Nucleic acids.
- They are a major class of Lipids.
- Therefore, the correct answer is B, "Lipids".
Question 7:
Which type of carbohydrates is most prevalent in nature?
Topic: Types and Abundance of Carbohydrates
Correct Answer: D) Polysaccharides
Detailed Hints:
- All options listed are types of carbohydrates, however, their existence and abundance in nature vary.
- While Monosaccharides, Disaccharides, and Oligosaccharides are present in nature, they are not as abundant as Polysaccharides.
- Polysaccharides, being the most complex type of carbohydrates, are the most abundant in nature.
- Therefore, the correct answer is D, "Polysaccharides".
Question 8:
Which lipid molecule possesses an uneven structure featuring a water-attracting head and a water-repelling tail with a phosphate group replacing one of its three fatty acid chains?
Topic: Structure of Lipids
Correct Answer: D) Phospholipid
Detailed Hints:
- Lipids are diverse in their structure and function. While waxes, terpenoids, and steroids are types of lipids, they do not possess the asymmetrical structure described in the question.
- Phospholipids are unique in their structure. They have a hydrophilic (water-attracting) head and a hydrophobic (water-repelling) tail.
- A key characteristic of phospholipids is the presence of a phosphate group in place of one of the three fatty acid chains.
- Therefore, the correct answer is D, "Phospholipid".
Question 9:
Which molecule is found in the highest quantities within living cells?
Topic: Abundance of Molecules in Cells
Correct Answer: D) Water
Detailed Hints:
- Living cells are composed of various molecules, including carbohydrates, lipids, proteins, and water.
- Despite the presence of carbohydrates, lipids, and proteins, they are not the most abundant within cells.
- Water is the most plentiful molecule within all living organisms.
- Thus, the correct answer is D, "Water".
Question 10:
How many carbon atoms do natural monosaccharides contain?
Topic: Structure of Monosaccharides
Correct Answer: B) 3-7
Detailed Hints:
- Monosaccharides are the simplest form of carbohydrates and they are classified based on the number of carbon atoms they possess.
- Options A, C, and D present a range of carbon atoms, but none of these ranges accurately describe natural monosaccharides.
- In nature, monosaccharides have 3 to 7 carbon atoms. They are referred to as triose(3), tetrose(4), pentose(5), hexose(6), and heptose(7).
- Hence, the correct answer is B, "3-7".
Question 11:
What type of glycosidic linkage is formed between glucose and fructose to create sucrose?
Topic: Structure of Disaccharides
Correct Answer: C) 1,2 glycosidic linkage
Detailed Hints:
- Glucose and fructose are monosaccharides that combine to form the disaccharide sucrose.
- The linkage between two monosaccharides in a disaccharide is known as a glycosidic linkage.
- The glycosidic linkage in sucrose is neither a 1,3, nor a 1,6, nor a 1,4 linkage.
- Therefore, the correct answer is C, "1,2 glycosidic linkage".
Question 12:
Myosin belongs to which category of proteins?
Topic: Types of Proteins
Correct Answer: D) Fibrous
Detailed Hints:
- Proteins are classified into several types: simple, intermediate, globular, and fibrous.
- Myosin does not fall under the categories of simple, intermediate, or globular proteins.
- It is a fibrous protein, as indicated in various diagrams.
- Hence, the correct answer is D, "Fibrous".
Question 13:
In what forms do lipids exist in the human body?
Topic: Forms of Lipids in the Human Body
Correct Answer: D) All of these
Detailed Hints:
- Lipids are present in various forms in the human body, including cholesterol, phospholipids, and triglycerides.
- Cholesterol, phospholipids, and triglycerides all belong to the class of lipids.
- Therefore, it's not just one of these; lipids are found in all these forms in the body.
- Thus, the correct answer is D, "All of these".
Question 14:
What is the term for the covalent bond that forms between two monosaccharides?
Topic: Formation of Disaccharides
Correct Answer: B) Glycosidic bond
Detailed Hints:
- Covalent bonds come in different forms, including disulphide, glycosidic, hydrogen, and peptide bonds.
- The bond that forms between two monosaccharides isn't a disulphide, hydrogen, or peptide bond.
- A glycosidic bond is indeed the covalent bond that forms between two monosaccharides, creating a disaccharide.
- Therefore, the correct answer is B, "Glycosidic bond".
Question 15:
Which substance is commonly referred to as the medium of life?
Topic: Importance of Water in Life
Correct Answer: D) Water
Detailed Hints:
- Various substances, including blood, carbon, lymph, and water, are vital to life as we know it.
- Neither blood, carbon, nor lymph is referred to as the medium of life.
- Water, which comprises about 70% of the human body's weight, is commonly known as the medium of life due to its essential role in biological processes.
- Hence, the correct answer is D, "Water".
Question 16:
How many different nitrogenous bases are present in nucleic acids?
Topic: Structure of Nucleic Acids
Correct Answer: C) Five
Detailed Hints:
- Nucleic acids contain a varying number of nitrogenous bases, with options ranging from four to seven.
- The total number of nitrogenous bases in nucleic acids is neither seven, six, nor four.
- In reality, nucleic acids contain five different nitrogenous bases: Adenine, Guanine, Cytosine, Thymine, and Uracil.
- Therefore, the correct answer is C, "Five".
MCQs 17:
What differentiates each of the 20 naturally occurring amino acids from each other?
Topic: Structure of Amino Acids
Correct Answer: D) R group
Detailed Hints:
- Amino acids, the building blocks of proteins, consist of various functional groups, including NH2 group, -OH group, -COOH group, and R group.
- The NH2 group, -OH group, and -COOH group are common to all amino acids, but the R group, or side chain, differs in each of the 20 naturally occurring amino acids.
- The R group gives each amino acid its unique properties.
- Therefore, the correct answer is D, "R group".
MCQs 18:
When the arrangement of amino acids in a polypeptide chain takes on a spiral form, what is this structure called?
Topic: Protein Structure
Correct Answer: C) Secondary structure
Detailed Hints:
- Protein structure is organized into four levels: primary, secondary, tertiary, and quaternary.
- A spiral or helix arrangement of the polypeptide chain is not indicative of a quaternary, tertiary, or primary structure.
- This spiral arrangement is known as the alpha-helix and it is a type of secondary structure in proteins.
- Hence, the correct answer is C, "Secondary structure".
MCQs 19:
Which of the following contains lactose?
Topic: Disaccharides
Correct Answer: B) Milk
Detailed Hints:
- Lactose is a type of sugar, specifically a disaccharide, found in various food products.
- It is not found in sugar cane, eggs, or fruits.
- Lactose is a sugar derived from galactose and glucose and it is found primarily in milk.
- Therefore, the correct answer is B, "Milk".
MCQs 20:
What is the most prevalent compound in living organisms, accounting for two-thirds of an adult's weight?
Topic: Composition of Living Organisms
Correct Answer: D) Water
Detailed Hints:
- Living organisms are composed of various compounds, including carbohydrates, proteins, lipids, and water.
- Although carbohydrates, proteins, and lipids are essential, they do not account for the majority of an adult's weight.
- Water is the most abundant compound in living organisms, making up about two-thirds of an adult's weight due to its universal presence in cells and body fluids.
- Therefore, the correct answer is D, "Water".
MCQs 21:
Which of the following molecules is underpinned by glycerol?
Topic: Lipid Structure
Correct Answer: D) Triglycerides
Detailed Hints:
- Several molecules, such as DNA, ATP, disaccharides, and triglycerides, play crucial roles in biochemical reactions.
- Glycerol does not form the backbone of DNA, ATP, or disaccharides.
- Triglycerides consist of three fatty acid molecules attached to a glycerol backbone, hence its name "tri" (three) and "glyceride" (glycerol).
- Therefore, the correct answer is D, "Triglycerides".
MCQs 22:
What properties does water possess?
Topic: Properties of Water
Correct Answer: C) Amphoteric
Detailed Hints:
- Water has unique properties that contribute to its role as the medium of life.
- While water can exhibit characteristics of acids and bases, it is not exclusively acidic or basic.
- Water is amphoteric, meaning it can act as both an acid and a base, making it a versatile solvent in biological systems.
- Hence, the correct answer is C, "Amphoteric".