important chapter for class 12 biology
Answers
Important Topics:
1. Modes of asexual reproduction
Important Topics:
1. Pre-fertilisation Events
2. Inbreeding depression
3. Double fertilisation
Important Topics:
1. Gametogenesis, Fertilisation and Events of Pregnancy
Important Topics:
1. Birth control methods
2. Sexually transmitted diseases
3. Techniques to treat infertility
a) The unit reproduction is thoroughly covered previously in class 10. The basics of the unit are same but certain sections are provided in detail.
b) While preparing for your exams you must focus on the reproduction of flowers. The definition of double fertilization with mechanism is frequently asked in exams.
c) If we talk about human reproduction, the process of reproduction with means of birth control and sexually transmitted diseases should not be missed.
Chapter 5 – Principles of Inheritance and Variation
Important Topics:
1. Mendel’s Laws
2. Post-Mendelian Genetics
3. Chromosomal Disorders and Pedigree analysis
Important Topics:
1. Structure of DNA
2. Experiments of F. Griffith, Hershey & Chase and Meselson & Stahl
3. Mechanism- replication, transcription and translation
4. Salient features of genetic code
5. lac operon
Important Topics:
1. Homologous and analogous organs
2. Adaptive radiation
3. Hardy-Weinberg principle
a) This is one of the most important units in the syllabus. While preparing for the exam you must have complete idea about Mendel and its crosses, post Mendelian genetics, chromosomal disorders and some idea about pedigree.
b) The molecular basis of inheritance includes important topics of structure of DNA and all the experiments related to that, genetic code on Operon theory is also very important.
c) From evolution point of view the difference between analogous and homologous organs, Hardy-Weinberg principle and adaptive radiation are important.
Chapter 8 – Human Health and Disease
Important Topics:
1. Life cycle of Plasmodium
2. Causative agents of different diseases and their mode of transmission
3. Difference between innate and adaptive immunity
4. AIDS and Drug Abuse
Important Topics:
1. Inbreeding and outbreeding
2. Single cell protein
Important Topics:
1. Microbes and their products
2. Sewage treatment
3. Biogas production
a) This unit is very much associated with the role that biology can play in human development and welfare.
b) It focuses on different areas at the same time, so one have wide outlook to understand the motive of these chapters.
c) From exam point of view one must have the idea about difference between innate and adaptive immunity, AIDS (its causes and treatment including the structure of AIDS virus)
d) Some of the most frequently asked questions from this unit include the topics like sewage and its treatment and biogas production plant.
Chapter 11 – Biotechnology: Principles and Processes
Important Topics:
1. Restriction enzymes
2. Cloning vectors
3. Transformation processes
Important Topics:
1. Bt cotton
2. RNA interference
3. Gene therapy
4. Genetically engineered insulin
a) This unit is very much application based and the questions asked are either short answer type questions or sometimes long answer type questions.
b) The important topics include cloning vectors, Bt cotton, PCR technology, restriction enzymes.
c) This unit is also important from entrance exam point of view, so it can be studied in detail for further benefit but if you want to focus primarily on board exams then you must study the selective topics.
Chapter 13 – Organisms and Population
Important Topics:
1. Population interactions
Important Topics:
1. Pyramids of number, energy and biomass
2. Nutrient cycling
3. Ecological Succession
Important Topics:
1. Causes of biodiversity losses
Important Topics:
1. Air pollution
2. Eutrophication and Biomagnification
a) This chapter is easy to understand and equally important to score good marks.
b) The topics in focus before exams must include: population interaction and various pyramids, Nutrient cycling, Ecological succession and air pollution. These topics are asked in short or long answer type questions.
c) Eutrophication and biological magnification are topics that are mostly asked for definition.