Class 12 Biology Important Question Answer solution with pdf. Here We Provides Class 1 to 12 all Subjects NCERT Solution with Notes, Question Answer, CBSE and HBSE Important Questions, MCQ and old Question Papers for Students.
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HBSE ( Haryana Board ) Solution of Class 12 Biology important Question And Answer solution for 2024 exams.
HBSE Class 12 Biology Important Question 2025
HBSE Class 12 Biology Important Question 2024-25
HBSE Class 12 Biology Chapter 1 – Sexual Reproduction in Flowering Plants Important Questions 2024-25
Q1. Explain the formation of Embryo sac in plants.
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With the help of diagram, describe the formation of embryo sac from megaspore mother cell in a flowering plants.
Q2. Describe the structure of pollen grain in detail.
Q3. Draw a diagram of L. S. of an embryo of grass. Label its all the parts.
Ans –
Q4. What is placenta ? Write down its functions.
Q5. Write down the characteristics of wind and insect pollinated flowers.
Q6. What is coleorrhiza ?
Ans – At its lower end, the embryonal axis has the radical and root cap enclosed in an undifferentiated sheath called coleorrhiza.
Q7. What is coleoptile ?
Ans – The portion of the embryonal axis above the level of attachment of scutellum is the epicotyl. Epicotyl has a shoot apex and a few leaf primordia enclosed in a hollow foliar structure called coleoptile.
Q8. Write about Multiple Ovulation Embryo Transfer Technology (MOET).
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Write the full form of MOET.
Q9. What is Apocarpous and Syncarpous ?
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What do you mean by Apocarpous ?
HBSE Class 12 Biology Chapter 2 – Human Reproduction Important Questions 2024-25
Q1. Explain in detail about menstrual cycle.
Q2. Describe the process of spermatogenesis.
Q3. Describe the process of fertilization and implantation in human beings.
Q4. Draw a well labelled sectional view of seminiferous tubule and explain its structure.
Q5. Draw a well labelled diagrammatic sectional view of mammary gland. Describe its structure.
Q6. Trace the development of the zygote upto its implantation in the uterus.
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Describe the changes take place from the formation of zygote to implantation in human.
Q7. Draw a well labelled diagram of human male reproductive system. Write about male sex accessory ducts.
Q8. Describe the structure of a sperm with the help of a well labelled diagram.
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Draw a well labelled diagram of human sperm.
HBSE Class 12 Biology Chapter 3 – Reproductive Health Important Questions 2024-25
Q1. Give an example of copper releasing IUD. How does it help in preventing pregnancy?
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Name various copper releasing IUDs. How do these help in contraception?
Q2. Explain sterilisation method of contraception.
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Write about surgical methods of contraception.
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What is vasectomy?
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What is tubectomy?
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Sterilisation procedure in the male is called _________.
Ans – Surgical methods, also called sterilisation, are generally advised for the male/female partner as a terminal method to prevent any more pregnancies. Surgical intervention blocks gamete transport and thereby prevent conception. Sterilisation procedure in the male is called ‘vasectomy’ and that in the female, ‘tubectomy’.
Q3. Mention two main causes of population explosion in India.
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What are the major causes of population explosion in India?
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What are the reasons of rise in our Population?
Q4. Mention any four features of an ideal contraceptive.
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What should be the features of an ideal contraceptive ?
Ans – An ideal contraceptive should be user-friendly, easily available, effective and reversible with no or least side-effects. It also should in no way interfere with the sexual drive, desire and/or the sexual act of the user.
Q5. What are the early symptoms of STD (Sexually Transmitted Disease)? What simple principles should be followed to prevent these diseases ?
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Write down early symptoms of STDs.
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What are the measures one has to take to prevent from contacting STDs?
Q6. Write full form of ICSI.
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Expand ICSI.
Ans – Intra cytoplasmic sperm injection
Q7. What is MTP and why it is used ?
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What is the need of MTP ?
Ans – Intentional or voluntary termination of pregnancy before full term is called medical termination of pregnancy (MTP). MTP is used to get rid of unwanted pregnancies. either due to casual unprotected intercourse or failure of the contraceptive used during coitus or rapes.
HBSE Class 12 Biology Chapter 4 – Principles of Inheritance and Variation Important Questions 2024-25
Q1. What is co-dominance ? Explain with an example.
Q2. What is incomplete dominance and Co-dominance?
Q3. Describe various chromosomal disorders found in human beings.
Q4. Why was Drosophila melanogaster found suitable to Morgan for his studies?
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Why Drosophila melanogaster was found suitable for Morgan’s work ?
Q5. What is Aneuploidy and Polyploidy?
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What is aneuploidy ?
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What is polyploidy ?
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What is Aneuploidy ? Give two examples of it.
Q6. What is point mutation ? Give an example.
Q7. Describe the mechanism of sex determination in birds.
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How sex determination occurs in birds?
Q8. What is Pedigree Analysis? How such an analysis can be useful?
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What is pedigree analysis?
Ans – An analysis of traits in a several of generations of a family is called the pedigree analysis. In the pedigree analysis the inheritance of a particular trait is represented in the family tree over generations.
Q9. What is monosomy and trisomy? Give one example of each.
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What is trisomy ?
HBSE Class 12 Biology Chapter 5 – Molecular Basis of Inheritance Important Questions 2024-25
Q1. Explain in detail about double helix model of DNA.
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Write down the salient features of double helix structure of DNA.
Q2. Describe the transformation principle proposed by Griffith.
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Describe transforming principle given in Griffith’s experiments.
Q3. Describe the important goals of human genome project.
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Describe the salient features of Human Genome.
Q4. What is the cause of sickle cell anaemia? What happens to RBC in this disease?
Q5. What happen in splicing, capping and tailing?
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What is Capping ?
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What is Splicing?
Ans – it is subjected to a process called splicing where the introns are removed and exons are joined in a defined order. hnRNA undergoes additional processing called as capping and tailing. In capping an unusual nucleotide (methyl guanosine triphosphate) is added to the 5′-end of hnRNA. In tailing, adenylate residues (200-300) are added at 3′-end in a template independent manner. It is the fully processed hnRNA, now called mRNA.
Q6. Name the scientific name of fruit fly.
Ans – Drosophila
Q7. What is genetic code ? Write its salient features.
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Write down the salient features of Genetic Code.
Q8. What is dual function of genetic code AUG?
Q9. Describe the structure of transcription unit in detail.
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Describe Transcription unit.
Q10. Describe translation in brief.
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Describe the process of Translation.
Q11. What is Biochemical Oxygen Demand (BOD) ? What does it indicate ?
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What is BOD?
Ans – BOD refers to the amount of the oxygen that would be consumed if all the organic matter in one liter of water were oxidised by bacteria. The sewage water is treated till the BOD is reduced. The BOD test measures the rate of uptake of oxygen by micro-organisms in a sample of water and thus, indirectly, BOD is a measure of the organic matter present in the water.
HBSE Class 12 Biology Chapter 6 – Evolution Important Questions 2024-25
Q1. Write about Miller’s experiment.
Q2. Write about Hugo de Vries theory of evolution. How does it differ from Darwin view?
Q3. Write down the features of Homo habilis, Homo erectus and Neanderthal man.
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Write down the characteristics of Homo habilis and Homo erectus.
HBSE Class 12 Biology Chapter 7 – Human Health and Disease Important Questions 2024-25
Q1. What is Allergy ? How does it take place & what are its symptoms ?
Q2. Write the name of causative organism and symptoms of disease Pneumonia, How does a healthy person acquire this infection ?
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Write name of causative organism, symptoms & mode of transmission of Pneumonia.
Q3. What are the harmful effects of using Tobacco ?
Q4. Write about opioids drugs.
Ans – Opioids are the drugs, which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract.
Q5. What is Innate Immunity? Write down its various barriers.
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Write about various barriers of innate Immunity.
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Explain barriers of innate immunity.
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What are the physical and cellular barriers of innate immunity?
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What are cytokine barriers?
Ans – Innate immunity is non-specific type of defence, that is present at the time of birth. This is accomplished by providing different types of barriers to the entry of the foreign agents into our body. Innate immunity consist of four types of barriers. These are —
(i) Physical barriers : Skin on our body is the main barrier which prevents entry of the micro-organisms. Mucus coating of the epithelium lining the respiratory, gastrointestinal and urogenital tracts also help in trapping microbes entering our body.
(ii) Physiological barriers : Acid in the stomach, saliva in the mouth, tears from eyes–all prevent microbial growth.
(iii) Cellular barriers : Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes.
(iv) Cytokine barriers : Virus-infected cells secrete proteins called interferons which protect non-infected cells from further viral infection.
Q6. Which diagnostic test is widely used to detect AIDS?
Ans – A widely used diagnostic test for AIDS is enzyme linked immuno-sorbent assay (ELISA)
Q7. By which test typhoid fever could be confirmed?
Ans – Widal Test
Q8. Name causative organism of Typhoid.
Ans – Salmonella typhi
Q9. What is “MALT” ?
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Write full form of MALT.
Ans – There is lymphoid tissue also located within the lining of the major tracts (respiratory, digestive and urogenital tracts) called mucosa associated lymphoid tissue (MALT).
Q10. Write about causes and treatment of Cancer.
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Write a note on treatment of cancer.
HBSE Class 12 Biology Chapter 8 – Microbes in Human Welfare Important Questions 2024-25
Q1. How Trichoderma polysporum is useful for human beings ?
Q2. Write down the role of Baculoviruses in biological control.
Q3. What is mycorrhiza ? What are its uses?
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What is mycorrhiza ? Write its advantages.
Q4. What is flocs ?
Q5. What is Antibiotic?
Q6. LAB is useful in production of household articles/products. How & when item it produces ?
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In which food lactic acid bacteria are present ? Write their useful applications.
Ans – Micro-organisms such as Lactobacillus and others commonly called lactic acid bacteria (LAB) grow in milk and convert it to curd. During growth, the LAB produce acids that coagulate and partially digest the milk proteins. A small amount of curd added to the fresh milk as inoculum or starter contain millions of LAB, which at suitable temperatures multiply, thus converting milk to curd, which also improves its nutritional quality by increasing vitamin B12.
Q7. How are flocs produced in the secondary treatment plant of Sewage ? Explain their role.
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Write note on secondary treatment in sewage treatment plant.
Q8. Which yeast is used for commercial production of Ethanol ?
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What is the scientific name of Yeast ?
Ans – Saccharomyces cerevisiae
Q9. Name the bacteria which can fix atmospheric nitrogen while free living in the soil.
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Write about the bacteria which fix atmospheric nitrogen.
Ans – Azospirillum and Azotobacter
HBSE Class 12 Biology Chapter 9 – Biotechnology : Principles and Processes Important Questions 2024-25
Q1. How are the desired DNA sequences used in biotechnology cut ? Explain the technique used to separate the cut fragments.
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Name the technique by which DNA fragments can be separated.
Q2. How can DNA be cut at specific locations ?
Q3. Write down various research areas of biotechnology.
Q4. What are the functions of Exonucleases and Endonucleases ?
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What are Exonucleases and Endonucleases ?
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Explain the role of Exonuclease.
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What is the role of Endonuclease ?
Q5. What is insertional inactivation.
Ans – A recombinant DNA is inserted within the coding sequence of an enzyme, β-galactosidase. This results into inactivation of the gene for synthesis of this enzyme, which is referred to as insertional inactivation.
Q6. Draw a well labelled diagram of E. Coli cloning vector pBR322 showing restriction sites and antibiotic resistance genes.
Q7. What are the various steps of PCR? From which bacteria thermostable DNA polymerase is isolated ?
HBSE Class 12 Biology Chapter 10 – Biotechnology and its Applications Important Questions 2024-25
Q1. What is RNA interference technique of cellular defence ? Explain with an example.
Q2. What is gene therapy? Illustrate using the example of adenosine deaminase (ADA) deficiency.
Q3. What is Gene Therapy?
Q4. What are transgenic animals? Explain the role of transgenic animals in biological products.
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Explain the role of transgenic animals in biological products.
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Write a note on biological products obtained from transgenic animals.
Q5. Why does the Bt toxin not kill the bacterium that produces it but kills the insect that ingest it ? Explain.
Q6. What is biopiracy?
Ans – Biopiracy is the term used to refer to the use of bio-resources by multinational companies and other organisations without proper authorisation from the countries and people concerned without compensatory payment.
Q7. Name the first transgenic cow. What is the advantage of its milk over than natural cow milk?
Ans – In 1997, the first transgenic cow, Rosie, produced human protein-enriched milk (2.4 grams per litre). The milk contained the human alpha-lactalbumin and was nutritionally a more balanced product for human babies than natural cow-milk.
Q8. The protein encoded by which gene controls corn borer ?
Ans – cryIAb
Q9. What are the advantages of production of genetically modified crops ?
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What are the advantages of genetically modified plants?
Q10. What are biotechnological applications in molecular diagnosis?
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How is biotechnology helpful in molecular diagnosis ?
Q11. What is GEAC. Write its role.
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Write full form of GEAC.
Ans – The Indian Government has set up organisations such as GEAC (Genetic Engineering Approval Committee), which will make decisions regarding the validity of GM research and the safety of introducing GM-organisms for public services.
Q12. Name the American Company who used the rDNA techniques to produce Human Insulin.
OR
In 1983, which American company prepared insulin?
Ans – Eli Lilly
HBSE Class 12 Biology Chapter 11 – Organisms and Populations Important Questions 2024-25
Q1. What is amensalism and commensalism?
Ans – The interaction where one species is benefitted and the other is neither benefitted nor harmed is called commensalism. In amensalism on the other hand one species is harmed whereas the other is unaffected.
Q2. What is Mutualism?
Ans – This interaction confers benefits on both the interacting species. Lichens represent an intimate mutualistic relationship between a fungus and photosynthesising algae or cyanobacteria.
Q3. Write about important defence mechanisms in plants against herbivory.
HBSE Class 12 Biology Chapter 12 – Ecosystem Important Questions 2024-25
Q1. Discuss importance of species diversity to the ecosystem.
Q2. What is decomposition ? Write about effect of temperature and moisture on this process.
Q3. Write about the factors which control rate of decomposition.
Q4. What is meant by productivity ? Differentiate between gross primary productivity and net primary productivity.
Q5. What is the theory of spontaneous generation ? Name the scientist who dismissed it.
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Name the scientist who dismissed the theory of spontaneous generation.
HBSE Class 12 Biology Chapter 13 – Biodiversity and Conservation Important Questions 2024-25
Q1. What are sacred groves ? Where are they found ? What is their role in biodiversity?
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Explain the role of sacred groves in conservation of biodiversity.
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What are sacred groves ?
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What are sacred groves ? Write down their role in conservation.
Q2. Explain the reasons/causes of Biodiversity loss.
Q3. Why should we conserve biodiversity ?
Q4. Where was the Earth Summit held in 1992 ?
Ans – Rio de Janeiro
Q5. Give three hypotheses for explaining why tropics show greatest levels of species richness.
Q6. What is Endemism?
Ans – species confined to that region and not found anywhere else is called endemism.
Q7. Where was the World Summit of Sustainable Development held in 2002 ?
Ans – Johannesburg, South Africa
Q8. Explain, why are very small animals rarely found in polar regions?
Q16. What is the impact of loss of Biodiversity ?
Q7. What are the consequences of loss of biodiversity in a region ?