Category: VBQs For Class 12

Short Answer Type Questions Question. Name the two type of nutrient cycles existing in nature. Where are their reservoirs present ? State the functions of the reservoirs.Answer : The nutrients are never lost from an ecosystem but are recycled time to time and again indefinitely.Nutrient cycles are of two types :(i) Gaseous cycles : The […]

Short Answer Type Questions Question. (i) What is an ‘‘allergic reaction’’ ?(ii) Name any two drugs used to quickly reduce the symptoms of allergy.(iii) Why do more and more children in metro cities of India suffer from allergies and asthma?Answer : (i) The exaggerated response of the immune system to certain antigens present in the environment is called […]

Very Short Answer Type Questions Question. Why are analogous structures, a result of convergent evolution ?Answer : Analogous structures are a result of convergent evolution because they are not anatomically similar structures though they perform similar functions. Detailed Answer :Analogous structures are said to be the result of convergent evolution because, though they perform a similar function […]

Very Short Answer Type Questions Question. Mention the contribution of genetic maps in human genome project. Answer : Sequencing of genes, DNA finger printing, tracing human history, chromosomal location for disease associated sequences. Question. Mention the role of the codons AUG and UGA during protein synthesis.Answer : AUG – codes for methionine / initiation codon.UGA – termination codon / stop codon.  Short […]

Short Answer Type Questions Question. Explain the laws that Mendel derived from his monohybrid crosses.Answer : Law of Dominance, states that factors that control characters occur in pairs and in dissimilar pair one factor dominates (expresses itself) whereas the other recessive factor does not express in the presence of the dominant one.Law of Segregation, states that during […]

Very Short Answer Type Questions Question. Name the pouch in which the human testes are present. Answer : Scrotum. Question. Name the cells that nourish the germ cells in the testes. Where are these located in the testes ?Answer : Name of cells—Sertoli cells.Location—They are found lining-up the inner surface of seminiferous tubules.  Question. Write the […]

Very Short Answer Type Questions Question. Explain the process of pollination in Vallisneria.Answer : The female flower reaches the surface of water by long stalk, male flower releases the pollen grains on surface of water, pollen grains are carried by water currents, some of them reach the stigma and achieve pollination.  Question. What is pollen–pistil interaction and how […]

Very Short Answer Type Questions Question. In which two of the following organisms is the fertilization external ?Bony fishes, ferns, frog, birds.Answer : Bony fishes and frogs.  Question. Which of the following statements is true for date palm.(i) It is monoecious producing both staminate and pistillate flowers in the same plant.(ii) It is monoecious producing staminate […]

Chapter 1 Reproduction in Organisms Chapter 2 Sexual Reproduction in Flowering Plants Chapter 3 Human Reproduction Chapter 4 Reproductive Health Chapter 5 Principles of Inheritance and Variation Chapter 6 Molecular Basis of Inheritance Chapter 7 Evolution Chapter 8 Human Health and Diseases Chapter 9 Strategies for Enhancement in Food Production Chapter 10 Microbes in Human […]