CBSE Class 8 Science Revision Notes Chapter 9
CBSE Class 8 Science Revision Notes Chapter 9 – Reproduction in Animals
Reproduction is a process by which organisms produce offspring of their own kind. Chapter 9 of Class 8 Science focuses on reproduction in animals. Students must understand its fundamentals thoroughly as it is an important chapter. Chapter 8 of Science ‘Reproduction in Animals’ is a simple and fascinating chapter. This chapter covers asexual and sexual reproduction, animal reproduction modes, fertilisation and its various types, binary fission, hydra budding, reproductive organs, and more. All possible questions and answers, diagrams, and fun activities are included in the material. Each line of the chapter is explained in such a way that any student can easily understand and memorise it.
Animal Reproduction Chapter 9 Science Notes are provided by Extramarks for CBSE Class 8 students to assist them in their exam preparation. These authentic and error-free notes prepared by subject matter experts will assist students in scoring deserving marks in the final exams. Students need not worry if the material is outdated as they are written according to the revised CBSE syllabus.
Notes on Reproduction in Animals Class 8 will allow students to revise key concepts before examinations. Students can easily recall topics such as female and male reproductive organs with comprehensive and illustrative notes. An advantage of these notes is that students can access them from anywhere and at any time. These Extramarks notes are ideal for revisions before examinations as students can quickly cover the chapter’s content in a lesser time.
Revision Notes for CBSE Class 8 Science Chapter 9
Access Class 8 Science Chapter 9–Reproduction in Animals Notes
- Sexual Reproduction
Sexual reproduction is a natural method of reproduction in humans, animals, and the majority of plants. This method of reproduction is more complicated and time-consuming than asexual reproduction. Additionally, sexual reproduction benefits from variance and produces one-of-a-kind offspring. Male and female reproductive organs are involved in sexual reproduction. Sexual reproduction is a type of reproduction that involves the fusion of male and female gametes.
Organs for Reproduction:
The testes, sperm ducts, and penis are the male reproductive organs, whereas the ovaries, oviducts, and uterus are the female reproductive organs. In contrast to the testes, which create male gametes known as sperms, the ovary produces female gametes known as ova (egg cells).
Fertilisation is the fusion of these gametes (ovum and sperm). A zygote is an egg that develops after fertilisation.
Types of Fertilisation:
Fertilisation is the process by which the male and female gametes fuse to form a zygote during sexual reproduction.
Fertilisation is divided into one of two categories depending on whether it occurs inside or outside the parent body:
- Internal Fertilisation
Internal fertilisation refers to fertilisation that occurs within the female species’ bodies. This phenomenon has been observed in humans as well as other animals such as hens, cats, dogs, and other mammals.
- External Fertilisation
External fertilisation refers to fertilisation that occurs outside of the female species’ body. This is commonly observed in aquatic animals such as frogs and fish.
Process of Fertilisation:
A zygote is formed after fertilisation and begins to develop into an embryo. The zygote divides repeatedly, producing an embryo that embeds itself in the uterine wall and develops into body parts. A zygote is the first stage of an organism’s development. It is formed by the fusion of male and female gametes.
A foetus is the final stage of an organism’s development. In most cases, the foetus develops internally. The stage of an embryo in which all of the major body parts of a mature organism can be seen.
Viviparous Animals:
Humans, cats, cows, and other mammals that give birth to young are referred to as viviparous animals.
Oviparous Animals:
Oviparous animals are those that lay eggs, such as frogs, lizards, and butterflies.
The larva is transformed into an adult during metamorphosis. It is seen in insects such as butterflies, silkworms, frogs, and so on.
- Asexual Reproduction
Asexual reproduction refers to this type of reproduction. This is the type of reproduction that requires only one parent. The new offspring created are clones of their parents because they have the same genetic makeup and physical characteristics. Both multicellular and unicellular species can reproduce asexually. For example, hydra, amoeba, and other microscopic unicellular organisms.
- Budding:
Budding is a method of asexual reproduction that involves the formation of buds. New hydra individuals emerge from buds formed by the parent body. Hydra uses regenerative cells to reproduce through the budding process. The formation of buds is the first step in this process, and it then develops as a small outgrowth on the parent’s body. The characteristics of the parent organism are passed down to the bud as it develops.
- Binary Fission:
Binary fission refers to asexual reproduction in which an organism divides itself into two from a single parent. The organism divides its nucleus into two parts using this method, and each part contains a nucleus. Microscopic organisms, such as amoeba, reproduce by dividing themselves in two.
Revision Notes for Class 8 Chapter 9 – Download
Reproduction in Animals Class 8 Notes are carefully curated by subject matter experts, who have included all important concepts in a point format. These notes are simple to read and understand, as it is written in simple language. Students can refer to these notes and memorise all the terms explained in the chapter. They will find Class 8 Science Chapter 9 Notes to be most useful during exams because they cover the key concepts of the chapter to aid in memory. These notes are easily accessible from the Extramarks website.
The following topics are covered in Extramarks Revision Notes for Chapter 9 of Class 8 Science:
- Modes of Reproduction (Sexual and Asexual)
- Male and Female Reproductive Organs
- Fertilisation
- Development of an Embryo
- Viviparous and Oviparous Animals
- Asexual Reproduction (Budding and Binary Fission)
Reproduction in Animals is an important chapter, and students must understand its fundamentals thoroughly because this knowledge serves as the foundation for further studies in higher classes and when students specialise in the subject of biology.
Reproduction is the process by which organisms produce offspring. It is divided into two types: asexual reproduction and sexual reproduction. When male and female gametes fuse, the reproduction process is called sexual reproduction; when only one parent is involved, the reproduction process is called asexual. Budding, in which offspring develop from buds, and binary fission, in which an amoeba reproduces by dividing itself in two, are two types of asexual reproduction.
Notes of Reproduction in Animals Class 8 can be used to quickly review concepts such as fertilisation, which is an important part of reproduction. Fertilisation is the process of fusing the ovum with the sperm. Internal fertilisation refers to fertilisation that occurs within the body, while external fertilisation refers to fertilisation that occurs outside the body.
The fertilisation process has been explained in simple terms in Chapter 9 Science Class 8 notes. Animals are classified as viviparous or oviparous based on the number of offspring they produce. Animals that give birth to young are referred to as viviparous, while those that lay eggs are referred to as oviparous.
Human reproduction is critical to the survival of the human species. It is the process by which living organisms produce new individuals. Reproduction ensures that traits and habitats are passed down from generation to generation. Without reproduction, the species will vanish from the earth, hence continuity is necessary.
Benefits of Class 8 Chapter 9 Revision Notes
The benefits of Reproduction in Animals Chapter 9 Science Notes are given below:
Students can cover the chapter’s content without skipping any key concepts with the help of the Class 8 Science Reproduction in Animals Notes.
These concise notes follow the revised CBSE syllabus and are written by subject matter experts, which makes them reliable study material for students to refer to.
Extramarks’ revision notes encapsulate the chapter’s comprehensive content. Therefore, students can revise the chapter more efficiently with these notes.
Students can focus on their studies better and spend quality time in revision with the assistance of Extramarks Revision Notes.
Revising these notes will help students keep the important concepts of the chapter fresh in their minds. Since these notes allow students to grasp the entire chapter in a nutshell, the information retained is concise and structured.
The topics covered in the Extramarks Revision Notes are well-structured. These notes also contain detailed and neat illustrations which help students understand complex concepts better.
