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Explore Class 12 Biology past and model questions by chapter, year, marks and question type.
178 questions found
How does diffusion differ from osmosis based on the types of molecules involved across a cell membrane? Explain how environmental factors influence the rate of diffusion.
Which of the following genetic disorders is caused by a point mutation?
Down’s Syndrome
Turner’s Syndrome
Sickle Cell Anaemia
Klinefelter’s Syndrome
A botanist observes scattered vascular bundles throughout the ground tissue in a plant stem. What is the most appropriate conclusion?
The plant is monocot.
The plant undergoes secondary growth.
The plant has an open vascular bundle.
The plant is a dicot.
How can GMOs be used to address global food security challenges and what are the potential environmental concerns and health risks associated with their use?
Name any two indigenous fish species. Discuss how integrated fish farming is advantageous over traditional fish farming.
Scientists proposed different models of DNA replication. Identify the biologically feasible model that occurs during the S-phase of interphase. Explain the mechanism of this replication process, highlighting the role of enzymes, and illustrate with necessary diagrams
What is the term called for the addition of individuals in a population from outside or from another population?
Emigration
Immigration
Migration
Dispersion
Which of the following terms describes pollen tube entry into the embryo sac of ovule through micropyle during fertilization?
Mesogamy
Chalazogamy
Syngamy
Porogamy
How do different photosynthetic pigments contribute to capturing light energy? Explain how cyclic and non-cyclic photo-phosphorylation generate ATP and NADPH, and illustrate these with appropriate charts.
Nephrons are the structural and functional unit of kidney. Illustrate the structure of nephron with a labelled diagram. What would happen if ADH is secreted insufficiently?
If a plant is placed in a sealed bell jar with limited oxygen, how will its energy production be affected over time?
ATP production will increase due to higher glycolysis.
The plant will rely on anaerobic respiration producing less ATP.
The citric acid cycle will become faster to make up for lack of oxygen.
The electron transport chain will continue functioning normally.
Differentiate between simple permanent tissue and complex permanent tissue on the basis of structure, types, cell composition and functions.
Briefly explain this type of propagation with an example.
Mention any two applications of this method.
Explain how color blindness is inherited as a sex-linked trait in humans. Illustrate the inheritance of colour blindness using suitable genetic crosses and analyze the resulting phenotypic outcomes. Based on your analysis, justify why this pattern is referred to as criss-cross inheritance.
Mention the causative agent, mode of transmission, symptoms of pulmonary tuberculosis. Highlight various strategies for its prevention. Why is it called “disease of poverty”?
Label part A, B, C, D.
Which is the first stage of embryonic development after fertilization in frog's zygote?
Blastulation
Morulation
Cleavage
Gastrulation
Which of the following structures in a plant is primarily responsible for regulating transpiration?
Xylem
Stomata
Root hairs
Phloem
Write function of A and D.