NCERT Solutions for Class 12 Biology

Chapter 1 of NCERT Solutions for Class 12 Biology deals with “Reproduction of Organisms”. First of all, reproduction is the biological process in which an organism gives rise to offspring. In this chapter, you will learn about how various organisms procreate. There are two types of reproduction. When offspring is produced by a single parent with or without the involvement of gamete formation, the reproduction is asexual. When two parents (opposite sex) participate in the reproductive process and also involve the fusion of male and female gametes, it is called sexual reproduction. In a nutshell,  this chapter teaches about types, modes, and the process of reproduction in different organisms.

In this chapter, you will learn about the structure, morphology, and the various processes involved in the sexual reproduction of flowering plants. These solutions also elaborates on subtopics such as pre-fertilisation: Structure and Events, Double fertilisation, Post fertilisation: Structure and Events, Apomixis and Polyembryony.

As the name suggests, in this chapter, you will learn about the human male and female reproductive system. Reproductive events in humans include the formation of gametes (gametogenesis), i.e., sperms in males and ovum in females. The subtopics covered in this chapter are the male reproductive system, the female reproductive system, gametogenesis, menstrual cycle, fertilisation and implantation, pregnancy and embryonic development, parturition and lactation. In the NCERT solutions for this chapter you will find diagrams, illustrations, flowcharts etc that are easily understandable which will help you comprehend the concept better.  

In the previous chapter, ie, Chapter 3, you learnt about the various functions of the human reproductive system. This chapter will focus on Reproductive health and how one can achieve it. The primary focus will be on maternal health and health of the child during pre-pregnancy and post pregnancy periods.  The sub topics covered are: Problems and Strategies, Population Explosion and Birth Control, Medical Termination of Pregnancy, Sexually Transmitted Diseases, Infertility.

Chapter 5 deals with Genetics and Evolution. Genetics is a branch of Biology that deals with the inheritance, as well as the variation of characters from parents to offspring. The process by which characters are passed on from one parent to offspring is called Inheritance. The degree of difference from their parents is referred to as Variation. The subtopics covered in this chapter are Mendel’s laws of inheritance, Inheritance of one gene, Inheritance of two genes, Sex determination, Mutation, Genetic disorders.

In this chapter, you will find solutions represented in the form of simplified diagrams showing the structure of DNA, RNA, the process of replication etc. In Class XI you have learnt that nucleic acids are polymers of nucleotides. It also includes subtopics such as The DNA, The search for Genetic material, RNA world, Replication, Transcription, Genetic code, Translation, Regulation of gene expression, Human genome project, DNAfFingerprinting etc.

What is Evolution? Evolution is the study of the history of life forms on Earth. The chapter deals with origin in life and evolution of life forms. The various diagrams and illustrations however make it easier for students to comprehend the concept. 

This chapter will answer questions like how to maintain optimum health, types of treatment and prevention. This chapter also addresses some serious diseases such as AIDS, Cancer etc. The chapter includes subtopics such as Common diseases in humans, Immunity, AIDS, Cancer, Drugs and Alcohol abuse.

This chapter primarily talks about biological principles applied to animal husbandry and plant breeding that contribute to the increase in food production. several techniques like embryo transfer technology, tissue culture techniques etc are discussed in detail. . Subtopics that are explained in the chapter are Animal husbandry, Plant breeding, single cell proteins, Tissue culture etc.

Microbes play a crucial role in the evolution of earth. They are tiny living creatures present all around us in air, water, soil and so on. However there are some microbes that cause severe infection and disease that can be fatal. Few of the subtopics are Microbes in household products, Microbes in industrial products, Microbes in sewage treatment, Microbes in production of biogas, Microbes as biocontrol agents, Microbes as biofertilizers.

This chapter deals with the in-depth study of principles and processes involved in biotechnology. Biotechnology deals with techniques of using live organisms or enzymes from organisms to produce products and processes useful to humans. Some of the sub topics covered in the chapter are Principles of biotechnology, Tools of recombinant DNA technology, Processes of recombinant DNA technology.

Biotechnology deals with industrial-scale production of biopharmaceuticals. The applications of biotechnology includes therapeutics, diagnostics, and genetically modified crops for agriculture and processed food, etc. The chapter includes sub topics such as Biotechnological applications in agriculture, Biotechnological applications in medicine, Transgenic animals, Ethical issues.

In this chapter, students will explore ecology both at an organism as well as at a population level.  Ecology is the branch of biology which deals with the interactions among organisms and between the organism and its physical environment. Its study is important to strike a balance between the development and maintenance of natural environments. Sub topics covered in this chapter are Organism and its environment, populations etc.

What is Ecosystem? An ecosystem can be understood as a functional unit of nature where living organisms interact among themselves and also with the surrounding physical environment. This chapter deals with topics such as organisms and its environment, factors affecting the microorganism etc. The sub topics covered in the chapter are Ecosystem–structure and function, Productivity, Decomposition, Energy flow etc

Biodiversity is the combination of different types of ecosystems, different species of organisms and their variants. The chapter Biodiversity and Conservations consist of topics like Genetic diversity, Species diversity, Ecological diversity, Different types of species, Patterns of diversity, Loss of biodiversity, Biodiversity conservation, etc.

This chapter deals with the arising problems that are posing threats to the ecological balance in nature. Such as pollution, global warming, deforestation etc.  Other subtopics students will encounter in this chapter are Air pollution and Its control, Water pollution and Its Control, Solid Wastes, Agrochemicals and their Effects etc. The concepts have also been updated as per the latest syllabus prescribed by CBSE.