All Free Biology MCQs with Answers

• A. Cristae
• B. Cisternae
• C. Lamella
• D. Bifidae

Explanation: Mitochondria are a double-membranous structure with an outer membrane and an inner membrane.

• A. Smooth Endoplasmic Reticulum
• B. Rough Endoplasmic Reticulum
• C. Golgi Apparatus
• D. Lysosomes

Explanation: Smooth endoplasmic reticulum in liver cells of vertebrates helps in detoxifying poisons and drugs.

• A. Mitochondria and ribosomes
• B. Cytosol, mitochondria and ribosomes
• C. Golgi bodies, Lysosome and ER
• D. Golgi bodies, lysosome and mitochondria

Explanation: The Golgi bodies, lysosomes, and endoplasmic reticulum are all examples of single membranous organelles.

• A. Phagocytosis
• B. Primary lysosome and autophagy
• C. Secondary lysosome
• D. Peroxisome

Explanation: Digestive vacuoles and autophagosomes eventually fuse with lysosomes, forming secondary lysosomes.

• A. Microtubule
• B. Cilia
• C. Microfilaments
• D. Intermediate filaments

Explanation: Cyclosis (the streaming movement of cytoplasm within a cell) and amoeboid movements (the crawling-like movements of certain cells, such as…

• A. Golgi complex
• B. Rough Endoplasmic Reticulum
• C. Smooth Endoplasmic Reticulum
• D. Ribosomes & chromosomes

Explanation: Proteins and lipids are modified into glycoproteins and glycolipids primarily by the Golgi complex (also known as the Golgi apparatus or…

• A. Enzymes
• B. Cisternae
• C. Pigment
• D. Cristae

Explanation: Chloroplasts are pigmented organelles, i.e, they contain some kind of pigment, which is chlorophyll.

• A. Intracellular digestion
• B. Autophagy
• C. Autolysis
• D. Processing of cell secretions

Explanation: The Golgi apparatus processes and packages cell secretions by receiving proteins and lipids from the endoplasmic reticulum in transport…

• A. Peroxisomes
• B. Glyoxysomes
• C. Microbodies
• D. Vacuoles

Explanation: Microbodies, which include organelles like peroxisomes and glyoxysomes, are present in plant cells during their normal metabolic…

• A. Its genetic constitution
• B. Its ability to over-produce
• C. Its ability to acquire characters
• D. Its ability to over-eat

Explanation: According to Darwin's theory of natural selection, the survival of an organism is influenced by its genetic constitution.

• A. Soil
• B. Atmosphere
• C. Water
• D. Animals

Explanation: d) Animals: This is the correct option. Animals are biotic components of the environment.

• A. Desert.
• B. Littoral.
• C. Profundal.
• D. All of these.

Explanation: The profundal zone is a deep zone of an inland body of freestanding water, such as a lake or a pond, located below the range of effective…

• A. Biogeochemical cycles
• B. Bioelement cycles
• C. Biochemical cycles
• D. Geochemical cycles

Explanation: Explanation:The nutrient cycles are primarily referred to as "Biogeochemical cycles" because they involve the cycling of nutrients such as…

• A. Population
• B. Community ecology
• C. Community
• D. Autecology

Explanation: [A] Correct definition for population[B] Community ecology;community ecology, study of the organisation and functioning of communities…

• A. Niche
• B. Ecosystem
• C. Habitat
• D. Biosphere

Explanation: A habitat is a place where an organism makes its home. A habitat meets all the environmental conditions an organism needs to survive.

• A. Symbiosis
• B. Predation
• C. Commensalism
• D. Parasitism

Explanation: Mycorrhiza is a mutualistic relationship between fungal hyphae and roots of higher plants.

• A. Food Chain
• B. Food Web
• C. Trophic Level
• D. Food Link

Explanation: A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another; the levels in the…

• A. Role played by many organisms in an ecosystem
• B. Role played by a dead organism in an ecosystem
• C. Role played by community of microorganisms in their ecosystem
• D. Role played by an organism in its ecosystem

Explanation: The niche of an organism is the role that it plays in a community, especially its living conditions and its interaction with other…

• A. Trophic level
• B. Food web
• C. Energy pyramid
• D. Food chain

Explanation: A trophic level refers to a level or a position in a food chain, a food web, or an ecological pyramid.

• A. Symbiosis
• B. Parasitism
• C. Commensalism
• D. Predation

Explanation: Symbiosis is the interaction of two dissimilar organisms, in which both organisms benefit from the interaction.