Q1. What is the primary molecule responsible for storing genetic information in living organisms?
a) DNA
b) RNA
c) Protein
d) Lipid
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Correct Answer: a) DNA
Explanation: DNA, or deoxyribonucleic acid, is the molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses.
Q2. Which organelle is responsible for producing energy in eukaryotic cells?
a) Nucleus
b) Mitochondria
c) Golgi apparatus
d) Endoplasmic reticulum
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Correct Answer: b) Mitochondria
Explanation: Mitochondria are often referred to as the powerhouse of the cell because they generate the majority of a cell’s supply of adenosine triphosphate (ATP), which is used as a source of chemical energy.
Q3. What is the process by which plants convert sunlight, carbon dioxide, and water into glucose and oxygen?
a) Respiration
b) Photosynthesis
c) Fermentation
d) Transpiration
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Correct Answer: b) Photosynthesis
Explanation: Photosynthesis is the biochemical process by which green plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy stored in glucose while releasing oxygen as a byproduct.
Q4. Which of the following is NOT a major macromolecule found in living organisms?
a) Carbohydrate
b) Lipid
c) Nucleotide
d) Hormone
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Correct Answer: d) Hormone
Explanation: Hormones are signaling molecules produced by glands in multicellular organisms, but they are not considered major macromolecules. Carbohydrates, lipids, and nucleic acids (nucleotides) are all examples of major macromolecules.
Q5. What is the basic structural and functional unit of all living organisms?
a) Atom
b) Cell
c) Tissue
d) Organ
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Correct Answer: b) Cell
Explanation: Cells are the basic structural and functional units of all living organisms. They vary in size, shape, and function, but they all share certain characteristics, such as the presence of genetic material and the ability to reproduce.
Q6. Which scientist is credited with the discovery of penicillin, the first antibiotic?
a) Alexander Fleming
b) Louis Pasteur
c) Robert Koch
d) Jonas Salk
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Correct Answer: a) Alexander Fleming
Explanation: Alexander Fleming, a Scottish bacteriologist, discovered penicillin in 1928. His accidental discovery revolutionized medicine by introducing the first antibiotic, which could effectively treat bacterial infections.
Q7. What is the process by which cells replicate their DNA to produce two identical copies?
a) Transcription
b) Translation
c) Replication
d) Mutation
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Correct Answer: c) Replication
Explanation: DNA replication is the process by which a cell makes an identical copy of its DNA before cell division. It ensures that each daughter cell receives a complete set of genetic information.
Q8. Which of the following is NOT a kingdom in the classification system of living organisms proposed by Carl Linnaeus?
a) Animalia
b) Plantae
c) Fungi
d) Protista
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Correct Answer: d) Protista
Explanation: Carl Linnaeus’ classification system includes the kingdoms Animalia, Plantae, and Fungi, but the kingdom Protista is a more recent addition proposed by Ernst Haeckel in the 19th century.
Q9. What is the process by which cells break down glucose to produce ATP in the absence of oxygen?
a) Photosynthesis
b) Respiration
c) Fermentation
d) Glycolysis
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Correct Answer: c) Fermentation
Explanation: Fermentation is an anaerobic process that occurs in the absence of oxygen, converting glucose into energy (ATP) and producing byproducts such as lactic acid or ethanol, depending on the organism.
Q10. Which of the following is NOT a characteristic of living organisms?
a) Growth and development
b) Reproduction
c) Response to stimuli
d) Inorganic composition
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Correct Answer: d) Inorganic composition
Explanation: Living organisms are characterized by various features, including growth and development, reproduction, response to stimuli, and organic composition. They are composed of organic molecules containing carbon-hydrogen bonds.