Access the latest CBSE Class 12 Biology All Chapters Question Bank. We have provided free printable Class 12 Biology worksheets in PDF format, specifically designed for All Chapters. These practice sets are prepared by expert teachers following the 2025-26 syllabus and exam patterns issued by CBSE, NCERT, and KVS.
All Chapters Biology Practice Worksheet for Class 12
Students should use these Class 12 Biology chapter-wise worksheets for daily practice to improve their conceptual understanding. This detailed test papers include important questions and solutions for All Chapters, to help you prepare for school tests and final examination. Regular practice of these Class 12 Biology questions will help improve your problem-solving speed and exam accuracy for the 2026 session.
Download Class 12 Biology All Chapters Worksheet PDF
Chapter-1: Reproduction in Organisms
Q.1. Explain the significance of meiocytes in diploid organisms.
Q.2. How is continuation of species maintained generation after generation?
Q.3. The cell division involved in gamete formation is not of the same type in different organism. Justify.
Q.4. Which is better mode of reproduction: sexual or asexual? Why?
Chapter-2: Sexual Reproduction in Flowering Plants
Q.1. Mention the scientific term used for the modified form of reproduction in which the seeds are formed without fusion of gametes.
Q.2. Describe the structure of a typical embryo sac found in flowering plants. Why it is generally referred to as monosporic.
Q.3. Why are non-albuminous seeds so called?
Q.4. Describe any two devices in a flowering plant which prevent both autogamy and geitonogamy.
Q.5. Where is sporopollenin present in plants? State its significance with reference to its chemical nature.
Q.6. How does megaspore mother cell develop into 7 celled 8 nucleate embryo sac in an angiosperm? Draw a labeled diagram of a mature embryo sac.
Q.7. Can a plant flowering in Mumbai be pollinated by the pollen grains of the same species growing in New Delhi? Provide explanation to the answer.
Chapter-3: Human Reproduction
Q.1. What is pregnancy hormone?Why is it so called?Name two sources of this hormone in human female.
Q.2. How is entry of only one sperm and not many,ensured into an ovum during fertilization in human.
Q.3. Write two major functions each of Testis and Ovary.
Q.4. State from where do the signals for parturition originate in human female.
Q.5. Describe the role of pituitary and ovarian hormones during the menstrual cycle of a human female.
Q.6. Differentiate between spermatogenesis and oogenesis.
Q.7. Explain menstrual cycle in human female. How can the scientific understanding of the menstrual cycle of human females help as a contraceptive measure?
Q.8. Draw a labeled diagram of sperm and write functions of each part.
Chapter-4: Reproductive Health
Q.1. Explain any two methods of Assisted Reproductive Technology.
Q.2. Mention any two events that are inhibited by intake of oral contraceptive pills to prevent pregnancy in humans.
Q.3. Explain how following act as contraceptives:
(a) CuT (b) Saheli
Q.4. Name any two intrauterine contraceptive devices that affect the motility of sperms.
Chapter-5: Principles of inheritance & Variation
Q.1. When a cross is made between tall plant with yellow seeds (TtYy) and tall plant with green seeds (Ttyy), what proportions of phenotype in offspring could be expected to be (a) tall and green (b)dwarf and green?
Q.2. A woman with Blood group O married a man with blood group AB. Show the possible blood groups of progeny. List the alleles involved in this inheritance.
Q.3. Explain the pattern of inheritance of hemophilia in humans. Why is the possibility of the human female becoming a hemophilic extremely rare, explain?
Q.4. How does a test cross help in identifying the genotype of the organism? Explain.
Q.5. Inheritance pattern of flower colour in garden pea plant and snapdragon differs. Why is this difference observed? Explain showing the crosses upto F2 Generation.
Q.6. Why are Thalesemia and hemophilia categorized as mendelian disorders? Write the symptoms of these diseases. Explain their pattern of inheritance in humans.
Chapter-6: Molecular basis of Inheritance
Q.1. Following are the features of genetic codes. What does each one indicate? Stop codon; unambiguous codon; Degenerate codon; Universal codons.
Q.2. Compare the role of enzymes DNA Polymerase and DNA Ligase in replication fork of DNA
Q.3. Write the dual purpose served by Deoxyribonucleoside triphosphates in polymerization.
Q.4. How were the following proved experimentally:
(a) Biochemical nature of the transforming principle in Griffith’s experiment.
(b) DNA is the genetic material.
Q.5. State the aim of the Messelson and Stahl‘s experiment. Describe the experiment briefly.
Q.6. Name the enzyme that catalyses the transcription of hnRNA. Why does the hnRNA need to undergo changes? Also list the changes.
Q.7. What do ‘Y’ and ‘B’ stands for in ‘YAC’ and ‘BAC’ used in Human Genome Project (HGP). Mention their role in the project. Expand SNPs identified by scientists in HGP .
Q.8. DNA polymorphism is the basis of DNA Fingerprinting Technique. Explain.
Chapter-7: Evolution
Q.1. How do Darwin finches illustrate adaptive radiation.
Q.2. Why are the wings of butterfly and bat called analogous.
Q.3. According to Hardy-Weinberg’s principle the allele frequency of a population remains constant. How do you interpret the change of frequency of alleles in a population?
Q.4. Name the scientist who disapproved spontaneous generation theory.
Q.5. Branching descent and natural selection are the two key concepts of Darwinian theory of evolution. Explain each concept with help of suitable example.
Q.6. What does Hardy –Weinberg equation convey p2+2pq+q2=1.
Q.7. Write the probable differences in eating habits of Homohabilis and Homoerectus.
Chapter-8: Human Health and Disease
Q.1. Explain what is meant by metastasis.
Q.2. Differentiate between a) Innate and acquired immunity b)Active and passive immunity.
Q.3. What role does macrophages play in providing immunity to humans?
Q.4. Explain the responses initiated when a dose of vaccine is introduced into the human body.
Q.5. How do cytokine barriers provide innate immunity in humans? ?
Q.6. Why does human beings elicit an anamestic response?
Q.7. How do macrophages in the human body acts as “HIV factory”?
Q.8. State the functions of mast cells in allergy response.
Q.9. Explain the property that prevents normal cells from becoming cancerous.
Q.10.Medically it is advised to all young mothers that breastfeeding is the best for their newborn babies.Do you agree? Give reasons in support of your answer.
Q.11.State the functions of primary and secondary lymphoid organs in human.
Q.12.Draw a well labeled diagram of an antibody molecule.
Chapter-9: Strategies for enhancement in food production
Q.1. Write the importance of MOET.
Q.2. How are somaclones produced? How are they different from somatic hybrids? Why are somaclones so called?
Q.3. “Honey collection improves when beehives are kept in crop fields during flowering season”. Explain.
Q.4. State the importance of Biofortification.
Q.5. What is inbreeding depression and how it is caused? Write two advantages of inbreeding.
Q.6. “Large scale cultivation of spirullina is highly advantageous for human population.”Explain giving two reasons.
Chapter-10: Microbes in Human Welfare
Q.1. During the secondary treatment of primary effluents, how a significant decrease in BOD does occurs.
Q.2. State the medicinal value and the bioactive molecules produced by the streptococcus, monascus purpureus and trichoderma polysporum.
Q.3. Name the fungus and its product used in organ transplant.
Q.4. Name some traditional Indian foods made of wheat, rice and Bengal gram for their products which involve use of microbes.
Q.5. Baculoviruses are excellent candidates for integrated pest management in ecologically sensitive area. Explain giving reasons.
Q.6. Name the metabolic pathway associated with the rising of dough in making bread. What makes the dough rise?
Chapter-11: Biotechnology: Principles and Processes
Q.1. What is the role of ethidium bromide during agarose gel electrophoresis of DNA Fragments?
Q.2. What are recombinant proteins? How do bioreactor help in their production?
Q.3. Why is it essential to have a selectable marker in a cloning vector?
Q.4. Differentiate between exonuclease and endonuclease.
Q.5. List the key tools used in RDT.
Q.6. Define PCR. Mention some of its practical applications.
Q.7. Describe briefly the following :
(a)Origin of replication
(b) Bioreactors.
Chapter-12: Biotechnology and Its Applications
Q.1. Explain the steps involved in the production of genetically engineered Insulin. Why is the insulin thus produced preferred over the one produced from animal source.
Q.2. What are Cry proteins? Name an organism that produces it.
Q.3. Explain RNA Interference in eukaryotes.
Q.4. Describe the gene therapy procedure for an ADA deficient patient.
Q.5. State the role of transposons in silencing of mRNA in eukaryotic cells.
Q.6. How did an American Company Eli Lily use the knowledge of r-DNA technology to produce human insulin?
Q.7. What is Biopiracy ?
Q.8. (a)Name the selectable markers in the cloning vector pBR322? Mention the role they play.
(b)Why is the coding sequence of an enzyme β-galactosidase a preferred selectable marker in comparison to the ones named above?
Chapter-13: Organism and Population
Q.1. How do snails, seeds, bears, zooplanktons, fungi and bacteria adapt to conditions unfavorable for their survival?
Q.2. Name the interaction in each of the following.
(a) Cuckoo laid her eggs in the crow’s nest.
(b) Orchid grows on a mango tree.
(c) Ticks live on the skin of dogs.
(d) Sea anemone is often found in the shells of the hermit crab.
(e) Association of Algae and Fungi
(f) A flower and its pollinator
(g) Fig plant species and wasp
Q.3. How do spines help cactus survive in the desert? Give 2 methods.
Q.4. Construct an age pyramid which reflects an expanding growth status of human population.
Q.5. Draw and explain logistic curve for a population of density (n) at time(t) whose intrinsic rate of natural increase is (r)and carrying capacity is (k).
Q.6. Differentiate between the following interspecific interaction in a population.
(a) Mutualism and Competition.
(b) Commensalism and Amensalism.
Q.7. Write what the phytophagous insect feed on.
(a) List the different attributes that a population has and not an individual organisms.
(b) What is population density? Explain any three different ways to measure population density with the help of examples.
Q.8. Describe the mutual relationship between fig tree and wasp and comment on the phenomenon that operates in their relationship.
Q.9. If a population growing exponentially double in size in 3 yrs, what is the intrinsic rate of increase (r) of the population?
Q.10. If 8 individuals in a population of 80 butterflies die in a week, calculate the death rate of population of butterflies during that period.
Q.11.(a)Name the two growth models that represent population growth and draw the respective growth curves they represent.
(b)State the basis for the difference in the shape of these curves.
(c)Which one of the curve represents the human population growth at present? Do you think such a curve is sustainable? Give reason in support of your answer.
Q.12.(a)Taking an example of a small pond,explain how the four components of an ecosystem function as a unit.
(b)Name the type of food chain that exists in a pond.
Q.13.Explain parasitism and co-evolution with the help of one example of each.
Please click on below link to download CBSE Class 12 Biology All Chapters Question Bank
| CBSE Class 12 Biology Evolution Question Bank |
| CBSE Class 12 Biology Evolution Worksheet Set A |
| CBSE Class 12 Biology Evolution Worksheet Set B |
| CBSE Class 12 Biology Biotechnology And Its Application Question Bank |
| CBSE Class 12 Biology Biotechnology and Its Applications Worksheet Set A |
| CBSE Class 12 Biology Ecosystem Question Bank |
| CBSE Class 12 Biology Ecosystem Worksheet Set A |
| CBSE Class 12 Biology Ecosystem Worksheet Set B |
Important Practice Resources for Class 12 Biology
All Chapters CBSE Class 12 Biology Worksheet
Students can use the All Chapters practice sheet provided above to prepare for their upcoming school tests. This solved questions and answers follow the latest CBSE syllabus for Class 12 Biology. You can easily download the PDF format and solve these questions every day to improve your marks. Our expert teachers have made these from the most important topics that are always asked in your exams to help you get more marks in exams.
NCERT Based Questions and Solutions for All Chapters
Our expert team has used the official NCERT book for Class 12 Biology to create this practice material for students. After solving the questions our teachers have also suggested to study the NCERT solutions which will help you to understand the best way to solve problems in Biology. You can get all this study material for free on studiestoday.com.
Extra Practice for Biology
To get the best results in Class 12, students should try the Biology MCQ Test for this chapter. We have also provided printable assignments for Class 12 Biology on our website. Regular practice will help you feel more confident and get higher marks in CBSE examinations.
Where can I download the latest PDF for CBSE Class 12 Biology All Chapters Question Bank?
You can download the teacher-verified PDF for CBSE Class 12 Biology All Chapters Question Bank from StudiesToday.com. These practice sheets for Class 12 Biology are designed as per the latest CBSE academic session.
Are these Biology Class 12 worksheets based on the 2026 competency-based pattern?
Yes, our CBSE Class 12 Biology All Chapters Question Bank includes a variety of questions like Case-based studies, Assertion-Reasoning, and MCQs as per the 50% competency-based weightage in the latest curriculum for Class 12.
Do you provide solved answers for CBSE Class 12 Biology All Chapters Question Bank?
Yes, we have provided detailed solutions for CBSE Class 12 Biology All Chapters Question Bank to help Class 12 and follow the official CBSE marking scheme.
How does solving CBSE Class 12 Biology All Chapters Question Bank help in exam preparation?
Daily practice with these Biology worksheets helps in identifying understanding gaps. It also improves question solving speed and ensures that Class 12 students get more marks in CBSE exams.
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