Here you got the ncert solutions for class 12 biology from chapter 1 to 16. NCERT play an important role in any competition and for the board exam. Therefore it’s essential and important for anyone to go through the NCERT solutions and concept. And here Studyzone provides you with all the NCERT solutions for class 12 biology chapter wise, which were solved by subject experts.
The chapter, Reproduction in Organisms, explains how various organisms can procreate. Reproduction is an essential biological process in which a plant gives rise to young ones similar to itself. There are two types of reproduction. When a single parent produces offspring with or without the involvement of gamete formation, the reproduction is asexual.
Sexual Reproduction in Flowering Plants explains the morphology, structure and the processes of sexual reproduction in angiosperms. It also elaborates on subtopics such as pre-fertilisation: Structure and Events, Double fertilisation, Post fertilisation: Structure and Events, Apomixis and Polyembryony.
There are remarkable differences between the reproductive events in the male and the female. In this chapter, you will examine the male and female reproductive systems in humans. The subtopics covered in this chapter are the male reproductive system.
In the previous chapter, you have learnt about the human reproductive system and its functions. This chapter discusses a closely related topic – reproductive health. The term refers to healthy reproductive organs with regular functions.
Inheritance is the process by which characters passed on from parent to progeny; it is the basis of heredity. Variation is the degree by which progeny differ from their parents. The chapter covers subtopics such as Mendel’s Laws of Inheritance, Inheritance of One Gene, Inheritance of Two Genes, Sex Determination, Mutation, Genetic Disorders.
In the previous chapter, you have learnt the inheritance patterns and the genetic basis of such models. At the time of Mendel, the nature of those ‘factors’ regulating the mode of inheritance was not clear. Over the next hundred years, the quality of the putative genetic material investigated culminating in the realisation that DNA – deoxyribonucleic acid – is the genetic material, at least for the majority of organisms. In Class XI, you have learnt that nucleic acids are polymers of nucleotides.
Evolutionary Biology is the study of the history of life forms on earth. It covers subtopics such as Origin of Life, Evolution of Life Forms – A Theory. What is the Evidence for Evolution? What is Adaptive Radiation? Biological Evolution, Mechanism of Evolution, Hardy – Weinberg Principle.
Health, for a long time, was considered as a state of body and mind where there was a balance of certain humour. Health is affected by – (i) genetic disorders – deficiencies with which a child is born and deficiencies/defects which the child inherits from parents from birth; (ii) infections and (iii) lifestyle including food and water we take, rest and exercise we give to our bodies, habits that we have or lack etc
Biological principles as applied to animal husbandry and plant breeding have a significant role in our efforts to increase food production. Several new techniques, like embryo transfer technology and tissue culture techniques, are going to play a pivotal role in further enhancing food production.
Microbes are diverse–protozoa, bacteria, fungi and microscopic animal and plant viruses, viroids and also prions that are proteinaceous infectious agents. Microbes like bacteria and many mushrooms can be grown on nutritive media to form colonies that can seen with the naked eyes.
The European Federation of Biotechnology (EFB) has given a definition of biotechnology that encompasses both traditional view and modern molecular biotechnology. The description provided by EFB is as follows: ‘The integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services.
The applications of biotechnology include therapeutics, diagnostics, genetically modified crops for agriculture, processed food, bioremediation, waste treatment, and energy production. The chapter also covers topics such as Biotechnological Applications in Agriculture, Biotechnological Applications in Medicine, Transgenic Animals, Ethical Issues
Ecology is concerned with four levels of biological organisation – organisms, populations, communities and biomes. In this chapter, we explore ecology at organismic and population levels. It also includes subtopics such as Organism and Its Environment, Populations.
In this chapter, we will first look at the structure of the ecosystem, to appreciate the input (productivity), transfer of energy (food chain/web, nutrient cycling) and the output (degradation and energy loss). We will also look at the relationships – cycles, chains, networks – that created as a result of these energy flows within the system, and they are interrelationship.
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. Biodiversity conservation may be in situ as well as ex-situ. In situ conservation, the endangered species are protected in their natural habitat so that the entire ecosystem is protected.
Human population size has grown enormously over the last hundred years. Means an increase in demand for food, water, home, electricity, roads, automobiles and numerous other commodities. Pollution is any undesirable change in physical, chemical or biological characteristics of air, land, water or soil. Agents that bring about such an adverse change are called pollutants.