Q21. Which of the following is NOT a function of the cell membrane?
a) Regulating the passage of substances in and out of the cell
b) Providing structural support to the cell
c) Facilitating cell communication
d) Protecting the cell from external threats
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Correct Answer: b) Providing structural support to the cell
Explanation: While the cell membrane does provide some structural support by maintaining the shape of the cell, its primary functions include regulating the movement of substances in and out of the cell, facilitating cell communication through receptor proteins, and protecting the cell from external threats such as pathogens and toxins.
Q22. What is the role of ribosomes in a cell?
a) Production of energy
b) Synthesis of proteins
c) Storage of genetic material
d) Regulation of cell growth
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Correct Answer: b) Synthesis of proteins
Explanation: Ribosomes are cellular organelles responsible for protein synthesis. They read the genetic instructions provided by messenger RNA (mRNA) and assemble amino acids into polypeptide chains according to the sequence encoded in the mRNA. This process occurs through translation, where ribosomes play a crucial role in linking amino acids together to form proteins.
Q23. Which of the following is NOT a type of muscle tissue in the human body?
a) Skeletal muscle
b) Smooth muscle
c) Cardiac muscle
d) Dense connective tissue
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Correct Answer: d) Dense connective tissue
Explanation: Dense connective tissue is a type of connective tissue found in the body, but it is not classified as muscle tissue. The three main types of muscle tissue are skeletal muscle, which is responsible for voluntary movement; smooth muscle, found in the walls of internal organs and blood vessels; and cardiac muscle, found in the heart.
Q24. What is the function of the pancreas in the human body?
a) Regulation of blood pressure
b) Production of digestive enzymes
c) Production of insulin
d) Filtration of blood
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Correct Answer: c) Production of insulin
Explanation: The pancreas is a vital organ with both endocrine and exocrine functions. One of its primary roles is to produce insulin, a hormone that regulates blood sugar levels by facilitating the uptake of glucose into cells for energy production or storage. Insulin deficiency or resistance can lead to diabetes mellitus.
Q25. What is the purpose of DNA replication?
a) To produce RNA molecules
b) To repair damaged DNA
c) To synthesize proteins
d) To produce identical copies of DNA
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Correct Answer: d) To produce identical copies of DNA
Explanation: DNA replication is the process by which a cell makes identical copies of its DNA molecules. This essential process ensures that each daughter cell receives a complete set of genetic information during cell division. DNA replication occurs before cell division and involves the unwinding of the DNA double helix, followed by the synthesis of complementary DNA strands.
Q26. Which of the following is NOT a function of the endoplasmic reticulum (ER)?
a) Synthesis of lipids
b) Protein folding and modification
c) Storage of genetic material
d) Calcium ion storage and release
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Correct Answer: c) Storage of genetic material
Explanation: The endoplasmic reticulum (ER) is a complex organelle involved in various cellular processes. It plays a crucial role in the synthesis of lipids, protein folding and modification, and the storage and release of calcium ions. However, it is not involved in the storage of genetic material, which is primarily carried out by the nucleus in eukaryotic cells.
Q27. Which of the following is responsible for the transmission of hereditary traits from parents to offspring?
a) Genes
b) Proteins
c) Enzymes
d) Hormones
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Correct Answer: a) Genes
Explanation: Genes are units of heredity that are passed from parents to offspring and contain instructions for building and maintaining an organism. They are composed of DNA and carry the genetic information that determines an individual’s traits, such as eye color, height, and susceptibility to certain diseases.
Q28. What is the primary function of the Golgi apparatus in a cell?
a) Energy production
b) Synthesis of ribosomes
c) Modification and packaging of proteins
d) Regulation of cell division
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Correct Answer: c) Modification and packaging of proteins
Explanation: The Golgi apparatus, also known as the Golgi complex, is responsible for modifying, sorting, and packaging proteins and lipids synthesized in the cell. It receives newly synthesized proteins from the endoplasmic reticulum (ER), processes them by adding various modifications, such as carbohydrates, and packages them into vesicles for transport to their final destinations within or outside the cell.
Q29. What is the function of the circulatory system in the human body?
a) Exchange of gases
b) Regulation of body temperature
c) Production of hormones
d) Digestion of food
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Correct Answer: a) Exchange of gases
Explanation: The circulatory system, also known as the cardiovascular system, is responsible for the transportation of blood, nutrients, gases, and waste products throughout the body. One of its primary functions is the exchange of gases, where oxygen is transported from the lungs to tissues and carbon dioxide is transported from tissues to the lungs for elimination.
Q30. What is the main function of the vacuole in plant cells?
a) Energy production
b) Storage of water and nutrients
c) Protein synthesis
d) Cell movement
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Correct Answer: b) Storage of water and nutrients
Explanation: Vacuoles are membrane-bound organelles found in plant cells, as well as some other eukaryotic cells. They primarily function as storage organelles, storing water, ions, nutrients, and waste products. Vacuoles help maintain turgor pressure, regulate cell volume, and store essential substances needed for various cellular processes.