CBSE Biology Class 12: Important Topics You Should Not Miss

Reproduction

This unit is very familiar to students because many topics are covered in Class 10. There could be questions related to the double fertilization. The topics of birth control and sexually transmitted diseases are also not to be ignored. Here are the important topics.

• Modes of asexual reproduction
• Pre-fertilisation events
• Inbreeding depression
• Double fertilisation
• Gametogenesis, fertilisation and events of pregnancy
• Birth control methods
• Sexually transmitted diseases
• Techniques to treat infertility



Genetics And Evolution

Students should give utmost importance to this unit. One should know complete details about the Mendel and its crosses and post Mendelian genetics besides the chromosomal disorders. This year we are expecting a question on genetic code on Operon theory. The Hardy-Weinberg principle and adaptive radiation are expected from evolution. Other important topics are:
Chromosomal disorders and pedigree analysis

• Structure of DNA
• Experiments of F. Griffith, Hershey & Chase and Meselson & Stahl
• Mechanism- replication, transcription and translation
• Salient features of genetic code
• Lac operon
• Homologous and analogous organs
• Adaptive radiation



Biology In Human Welfare

Try to understand the motive behind the concepts because it will provide other information too. One should know the differences between innate and adaptive immunity. Students should give importance to topics such as sewage treatment, biogas production plant. Other important areas:

• Life cycle of Plasmodium
• Causative agents of different diseases and their mode of transmission
• AIDS and drug abuse
• Inbreeding and outbreeding
• Single cell protein
• Microbes and their products



Biotechnology

The questions from this unit can be either short or long answer type. This unit plays a key role in the entrance examination also. So go for a detail study but focus on the board exam point of view.

• Restriction enzymes
• Cloning vectors
• Transformation processes
• Bt cotton
• RNA interference
• Gene therapy
• Genetically engineered insulin



Ecology And Environment

This is an easy area to score in the examination. One should give importance to ecological succession, nutrient cycling and air pollution because they are usually ask for long answer questions. Focus on eutrophication also. Other important topics are:

• Population interactions
• Pyramids of number, energy and biomass
• Causes of biodiversity losses
• Biomagnification