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Explore Class 12 Biology past and model questions by chapter, year, marks and question type.
178 questions found
Draw the given diagram and label the tissues which is responsible for secondary growth. Elaborate the activities of this tissue up to the formation of the cambial ring.
The given vascular bundle is highly specialised by centripetal protoxylem. What is it called?

Exarch
Endarch
Mesarch
Centrach
There are many types of chromosomal disorders in organisms, among them euploidy is very common in the population. Which one of the following conditions is true for euploidy?
Addition or deletion of one or more chromosome in diploid chromosome
Addition of one or more chromosome in diploid chromosome
Deletion of one or more chromosome in diploid chromosome
Addition or deletion of one set or more than one set of chromosomes in diploid chromosome
Write the main characteristics of the given layer Y.
When a plant cell is placed in a hypertonic solution, it gets plasmolysed as shown in the diagram. Which of the following occupies the space between the cell wall and the shrunken protoplast in such a plasmolysed cell?

Water
Hypertonic solution
Isotonic solution
Hypotonic solution
The formation of two male gametes is a peculiar feature in angiosperm. If the first male gamete is fused to oosphere, in which part does the second male gamete fuse?
Synergids
Egg cell
Polar nuclei
Antipodal cell
Which of the following plants is used as biofertilizer?
Ko/vox
Funaria
Azolla
Rhizopus
One of the Mendelian inheritances states that ’The alleles of different traits can be segregated during gametogenesis and passed independently’. State and explain the essential pattern of inheritance verifying the statement with examples showing cross up to second filial generation with chart and ratio
Draw a labelled drawing of the respiratory system of a human being. Why and how oxygen and carbon dioxide are exchanged rapidly in the lungs? What would happen if a person moves to a high altitude? Write your views on how to solve
Draw a labelled diagram of the alimentary canal of a human being. Explain the mechanism of the digestion of foods that a person undertakes. What would happen in the digestion when the pancreas is removed?
Mention the causative agent, mode of transmission, symptoms and control measures of tuberculosis in the community.
Overpopulation is a major issue in the development of the nation. Highlight the socioeconomic problems caused by overpopulation and mention how to solve such problems.
Any three differences between A and B are:
Label A and B.
Describe the various steps applied in poultry farming.
Describe the process of fertilization of an egg with reference a frog.
Compare and contrast areolar tissue and adipose tissue
A person suddenly falls down and becomes unconscious. A doctor checked and said that it is due to inadequate blood supply to the brain. What would be the type of disorder?
Asthma
Syncope
Heart attack
Oedema
Blood cells are formed in the bone marrow. What is the process of formation of blood called?
Haemopoiesis
Haemolysis
Lymphopoiesis
Erythroblastosis
What are the main processes involved in gastrulation of a frog?
Epiboly, involution, cleavage
Epiboly, invagination, Involution
Involution, epiboly, invagination
Involution, invagination, cleavage.