Q21. Chiasmata are formed during which stage of meiosis I?
[A] Leptotene
[B] Zygotene
[C] Pachytene
[D] Diplotene
Show Answer
Correct Answer: [D] Diplotene
Explanation: Chiasmata are X-shaped structures that represent sites where crossing over has occurred between non-sister chromatids during meiosis. Chiasmata become visible during diplotene stage of prophase I as the synaptonemal complex dissolves and homologous chromosomes begin to separate, remaining attached at chiasmata. Leptotene is condensation, zygotene is synapsis, pachytene is crossing over itself.
Q22. The basic unit of carbohydrates is:
[A] Amino acids
[B] Fatty acids
[C] Monosaccharides
[D] Nucleotides
Show Answer
Correct Answer: [C] Monosaccharides
Explanation: Monosaccharides are the simplest sugars and the basic building blocks or monomers of carbohydrates. They are single sugar units, like glucose, fructose, and galactose. Amino acids are monomers of proteins, fatty acids are components of lipids, and nucleotides are monomers of nucleic acids.
Q23. Which of the following is a polysaccharide?
[A] Glucose
[B] Fructose
[C] Sucrose
[D] Starch
Show Answer
Correct Answer: [D] Starch
Explanation: Starch is a polysaccharide, a complex carbohydrate made up of many glucose units linked together. It is the main storage polysaccharide in plants. Glucose and fructose are monosaccharides (simple sugars). Sucrose is a disaccharide (two monosaccharides linke[D].
Q24. Glycogen is a polysaccharide stored in:
[A] Plant cells
[B] Animal cells
[C] Fungal cells
[D] Bacterial cells
Show Answer
Correct Answer: [B] Animal cells
Explanation: Glycogen is the storage polysaccharide of animals and fungi, analogous to starch in plants. It is a branched polymer of glucose, primarily stored in liver and muscle cells in animals. Plant cells store starch, fungal cells also store glycogen, and bacterial cells can store various polysaccharides but not typically glycogen as their primary storage form like in animals.
Q25. Proteins are polymers of:
[A] Monosaccharides
[B] Fatty acids
[C] Amino acids
[D] Nucleotides
Show Answer
Correct Answer: [C] Amino acids
Explanation: Proteins are polymers made up of amino acids as monomers. Amino acids are linked together by peptide bonds to form polypeptide chains, which fold into specific 3D structures to become functional proteins. Monosaccharides are for carbohydrates, fatty acids for lipids, and nucleotides for nucleic acids.
Q26. Which of the following is NOT a function of proteins?
[A] Catalysis of reactions (enzymes)
[B] Structural components (collagen)
[C] Genetic information storage
[D] Transport of molecules (haemoglobin)
Show Answer
orrect Answer: [C] Genetic information storage
Q27. Lipids are generally insoluble in water because they are:
[A] Hydrophilic
[B] Hydrophobic
[C] Amphipathic
[D] Polar
Show Answer
Correct Answer: [B] Hydrophobic
Q28. Fats and oils are examples of:
[A] Phospholipids
[B] Steroids
[C] Triglycerides
[D] Waxes
Show Answer
Correct Answer: [C] Triglycerides
Q29. Cholesterol is an example of:
[A] Phospholipid
[B] Triglyceride
[C] Steroid
[D] Wax
Show Answer
Correct Answer: [C] Steroid
Q30. Nucleic acids are polymers of:
[A] Amino acids
[B] Monosaccharides
[C] Fatty acids
[D] Nucleotides
Show Answer
Correct Answer: [D] Nucleotides