Q41. Which cellular process is responsible for the breakdown of glucose to form pyruvate?
a) Photosynthesis
b) Cellular respiration
c) Glycolysis
d) Krebs cycle
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Correct Answer: c) Glycolysis
Explanation: Glycolysis is the metabolic pathway that breaks down glucose into pyruvate, yielding ATP and NADH. This process is the first step in cellular respiration and occurs in the cytoplasm of the cell.
Q42. The primary sites of protein translation in eukaryotic cells are
a) The nucleus
b) Mitochondria
c) Ribosomes
d) The Golgi apparatus
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Correct Answer: c) Ribosomes
Explanation: Ribosomes are the primary sites of protein synthesis or translation in eukaryotic cells. They read the mRNA and translate the encoded information into a sequence of amino acids, forming proteins.
Q43. What is the primary function of the cell wall in plant cells?
a) Photosynthesis
b) Energy production
c) Structural support and protection
d) DNA replication
Correct Answer: c) Structural support and protection
Explanation: The primary function of the cell wall in plant cells is to provide structural support and protection. Made mainly of cellulose, the cell wall maintains the shape of the cell, offers rigidity, and helps resist mechanical stress.
Q44. What is the main role of the nucleolus within the cell nucleus?
a) Energy production
b) Lipid synthesis
c) Synthesis of ribosomal RNA (rRNA)
d) Protein sorting and packaging
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Correct Answer: c) Synthesis of ribosomal RNA (rRNA)
Explanation: The main role of the nucleolus within the cell nucleus is the synthesis and assembly of rRNA, a critical component of ribosomes. The nucleolus plays a significant role in the production of ribosomes, essential for protein synthesis.
Q45. In eukaryotic cells, the organelles responsible for energy conversion from organic compounds are
a) Lysosomes
b) Ribosomes
c) Mitochondria
d) Peroxisomes
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Correct Answer: c) Mitochondria
Explanation: In eukaryotic cells, mitochondria are the organelles responsible for the conversion of energy stored in organic compounds into ATP, the cell’s main energy currency. They perform this through the process of cellular respiration.
Q46. The unique structure in animal cells involved in organizing microtubules during cell division is known as the
a) Nucleolus
b) Centrosome
c) Golgi apparatus
d) Endoplasmic reticulum
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Correct Answer: b) Centrosome
Explanation: The centrosome is a unique structure in animal cells that plays a crucial role in organizing microtubules during cell division. It ensures the correct alignment and segregation of chromosomes.
Q47. What cellular structures are primarily involved in the process of endocytosis?
a) Mitochondria
b) Golgi apparatus
c) Vesicles
d) Ribosomes
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Correct Answer: c) Vesicles
Explanation: Vesicles are primarily involved in the process of endocytosis. They are small, membrane-bound sacs that transport substances into the cell by enclosing the material and merging with the cell membrane.
Q48. During protein synthesis, what is the role of transfer RNA (tRNA)?
a) Carrying amino acids to the ribosome
b) Unwinding the DNA helix
c) Catalyzing peptide bond formation
d) Transcribing DNA to mRNA
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Correct Answer: a) Carrying amino acids to the ribosome
Explanation: During protein synthesis, the role of transfer RNA (tRNA) is to carry amino acids to the ribosome. Each tRNA matches its specific amino acid to the corresponding codon on the mRNA strand, aiding in the assembly of the protein.
Q49. Cell junctions that allow for the direct communication between adjacent cells are called
a) Tight junctions
b) Desmosomes
c) Gap junctions
d) Adherens junctions
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Correct Answer: c) Gap junctions
Explanation: Gap junctions are cell junctions that provide direct communication channels between adjacent cells. They allow for the transfer of ions, nutrients, and other small molecules, facilitating coordinated responses in cellular activities.
Q50. The process in which a mature cell specializes into a specific cell type is called
a) Mitosis
b) Meiosis
c) Differentiation
d) Morphogenesis
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Correct Answer: c) Differentiation
Explanation: Cell differentiation is the process by which a less specialized cell becomes a more specialized cell type. This is crucial in the development of a multicellular organism, as it allows for the formation of various cell types with distinct functions.