Reproduction In Organisms: Overview, Topics, MCQs, Tips, Books
Reproduction in organisms describes the biological process through which living beings produce offspring, thereby ensuring that their species continues generation after generation. With microorganisms, plants, and animals, the process of birth, growth, and death go hand in hand to ensure survival. In competitive exams like NEET, questions are asked from asexual to sexual reproduction. Reproduction in Organisms is an important chapter of Biology and it is covered in the Class 12 syllabus. Know the important topics along with the overview of the chapter, modes of reproduction, reproduction in plants and animals, MCQs, tips and books.
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- Important Topics of Chapter Reproduction in Organisms
- Overview of the Chapter
- Importance of Reproduction in Organisms
- Modes of Reproduction in Organisms
- Asexual Reproduction
- Sexual Reproduction
- Reproduction in Plants
- Reproduction in Animals
- Tips, Tricks, and Strategies to Prepare for the Chapter Reproduction in Organisms
- Types of Questions and Weightage on Reproduction in Organisms in Exams
- Prescribed Books for Reproduction in Organisms
- Recommended Video on Reproduction in Organisms
Important Topics of Chapter Reproduction in Organisms
- Modes of Reproduction
- Reproduction in Plants
- Reproduction in Animals
- Important Concepts - Fertilization, budding, fission, vegetative propagation
Overview of the Chapter
The chapter on Reproduction in Organisms explains the methods adopted by organisms to ensure the survival of the species, discussing both asexual and sexual reproduction. It describes all the asexual modes of reproduction such as binary fission, budding, and vegetative propagation and discusses their benefits for the rapid increase in the population. Sexual reproduction with the formation of the gametes, fertilization, and reproductive structures in plants and animals are also discussed.
Importance of Reproduction in Organisms
Survival of Species: This is because reproduction ensures that species continue from generation to generation. Every living thing is bound to have a specific lifespan.
Genetic Diversity: Sex reproduction brings forth new variations that help in survival and adaptation by species to new-found or altered environments.
Population Regeneration: This mechanism ensures that populations of organisms remain stable and thereby avert extinctions.
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Modes of Reproduction in Organisms
Replication of organisms takes the following two broad forms:
Asexual Reproduction
Involves an individual or parent organism dividing to give rise to genetically identical offspring, that is, clones.
Dominant in single-celled organisms, fungi, and several types of plants.
Examples
- Amoeba: Reproduces through binary fission.
- Bacteria: May reproduce through either binary fission or budding.
- Hydra: Produces the new individual by budding.
- Plants: Algae, e.g., Chlamydomonas, produces zoospores.
NCERT Books Link:
Sexual Reproduction
- It involves the fusion of male and female gametes to create a zygote.
- Mostly occurs in advanced organisms like animals and flowering plants.
Main Events:
- Teen Stage: The growth stage is where the reproductive organs start developing.
- Reproductive Stage: Gamete formation, floral formation in flowering plants, and sexual characteristics reach maturity.
- Senescence Stage: It comprises the ageing and weakening stages of reproductive ability.
NCERT Notes Subject Wise Link:
- NCERT notes Class 12 Maths
- NCERT notes Class 12 Physics
- NCERT notes Class 12 Chemistry
- NCERT notes Class 12 Biology
Stages of Sexual Reproduction
Sexual reproduction in organisms follows the following main events:
Events Before Fertilization:
The Process of Gametogenesis
- The creation of gametes (sperm and eggs).
- Transfer of gametes from one organism to the other.
Fertilization Events:
- Syngamy: Fusion of gametes; ultimately leads to the formation of a zygote.
- This may occur by either External fertilization or Internal fertilization.
Post-Fertilization Events:
- Formation of Zygote: The diploid cell of the union undergoes cleavage and forms an embryo.
- Embryogenesis: The stages when the zygote develops into a mature organism through successive cell divisions.
NCERT Solutions Subject-wise link:
- NCERT solutions for class 12 Physics
- NCERT solutions for class 12 Chemistry
- NCERT solutions for class 12 Mathematics
- NCERT solutions for class 12 Biology
Reproduction in Plants
Reproduction in Plants is the biological process by which plants make new offspring; therefore, the continuation of their species. There are two ways that plants reproduce in the main: asexual reproduction and sexual reproduction.
Asexual Reproduction
In asexual reproduction, one parent gives rise to offspring that are genetically identical to the parent. Common methods include:
Vegetative Propagation
This comprises specialized structures such as:
Roots: Some plants may grow from their root systems and can eventually produce new individuals (e.g., dandelions).
Stems: Cutting, layering, and runners (for example, strawberries) can result in new plants.
Leaves: Some plants can grow into new individuals using leaf cuttings or even parts of a leaf (e.g., Bryophyllum).
Sexual Reproduction
Sexual reproduction involves the combination of the gametes of a male with those of a female, resulting in offspring displaying genetic variation. It usually consists of the following stages:
Pollination: The process of transference of pollen grains from the male anther of a flower to the female stigma. This can occur through the agency of wind, water, or animals.
Fertilization: This is when the pollen, once it has reached the stigma, germinates and forms a pollen tube that will get to the ovule where fertilization will take place to form a zygote.
Seed Development: Following fertilization, the zygote develops an embryo inside the seed, protective tissues, and a supply of food
Seed Dispersal: Seeds will be dispersed away from the parent plant through a variety of mechanisms that include wind, water, animals, and explosive mechanisms.
Germination: The seed absorbs water swells, and the embryo grows into a new plant when it faces a favourable environment.
Reproduction in Animals
Reproduction is a biological process whereby animals reproduce offspring, hence continuing their species. Animal reproduction occurs in one of the two types of reproduction mainly: sexual or asexual reproduction.
Asexual Reproduction
In this type of reproduction, there is a single parent resulting in offspring that are genetically identical to the parent. It is a simple and rapid process where the forms include:
Budding: A new organism is formed when an outgrowth known as the bud, arises on the parent. This takes place in organisms like hydra and yeast.
Fission: The parent splits up into two or more entities that are different from one another. Such reproduction takes place in unicellular organisms like the amoeba, while certain multicellular organisms, such as the flatworm, also exhibit fission.
Fragmentation: An organism breaks into fragments. Those fragments can become a new individual. This is common among starfish and certain types of worms.
Parthenogenesis: It is another form of reproduction. In this, the egg develops into a new individual without being fertilized. It can be seen in insects, reptiles, and some amphibians.
Sexual Reproduction
Sexual reproduction is characterized by the fusion of gametes from both males and females, resulting in genetically diverse offspring. This can be viewed as follows, in a nutshell, in a usual case of such a process:
Formation of Gametes: Sperm and eggs are reproductive cells, produced by meiosis from both males and females, thereby halving the number of chromosomes.
Fertilization: The male gamete or sperm unites with the female gamete or egg to form a zygote. The fertilization takes place either inside or outside the mother's body, based on the species. In some species, such as fish and frogs, eggs, and sperm, fertilize within the water. Examples of mammals that fertilize an egg inside the mother's body include human beings.
Embryonic Development: The cell division and growth take place in the zygote, forming the embryo. Later this embryo will develop into a juvenile and then an adult.
Birth or Hatching: In viviparous animals, such as mammals, the young are born live, meaning they develop inside a mother's body. In oviparous animals, which include birds and reptiles, eggs are laid and hatch after some incubation time.
MCQs on Reproduction in Organisms
Here are reproduction in organisms class 12 questions and answers to practice for NEET and Class 12 board Exams
Which of the following is a method of asexual reproduction?
- A) Fertilization
- B) Budding
- C) Pollination
- D) Oviparity
Answer: B) Budding
In which type of reproduction do offspring inherit genetic material from two parents?
- A) Asexual reproduction
- B) Sexual reproduction
- C) Binary fission
- D) Fragmentation
Answer: B) Sexual reproduction
Which of the following organisms reproduces by parthenogenesis?
- A) Frog
- B) Honeybee
- C) Chicken
- D) Lizard
Answer: B) Honeybee
What is the term for the fusion of male and female gametes?
- A) Budding
- B) Fertilization
- C) Fragmentation
- D) Binary fission
Answer: B) Fertilization
Which of the following is NOT a form of asexual reproduction?
- A) Spore formation
- B) Vegetative propagation
- C) Sexual reproduction
- D) Fission
Answer: C) Sexual reproduction
In flowering plants, which structure develops into a seed after fertilization?
- A) Ovary
- B) Stigma
- C) Anther
- D) Petal
Answer: A) Ovary
What type of fertilization occurs in most mammals?
- A) External fertilization
- B) Internal fertilization
- C) Asexual reproduction
- D) Parthenogenesis
Answer: B) Internal fertilization
Which of the following is a characteristic of sexual reproduction?
- A) Offspring are genetically identical to the parent.
- B) It involves the formation of gametes.
- C) It occurs through fragmentation.
- D) It is a rapid method of reproduction.
Answer: B) It involves the formation of gametes.
The process by which a single parent organism breaks into fragments that develop into new individuals is called:
- A) Binary fission
- B) Budding
- C) Fragmentation
- D) Cloning
Answer: C) Fragmentation
In which of the following organisms does external fertilization primarily occur?
- A) Humans
- B) Reptiles
- C) Frogs
- D) Birds
Answer: C) Frogs
Tips, Tricks, and Strategies to Prepare for the Chapter Reproduction in Organisms
Here are some tips and tricks to prepare for the Chapter Reproduction in Organisms:
Mnemonics
Use the term "GEMS" as a Mnemonic for the successive stages of Sexual Reproduction: Gametogenesis, External/Internal fertilization, Maturation of the zygote, and Sexual characteristics development.
Diagrams
Labelled diagrams of the structure of the reproductive organs in plants and animals
Draw a diagrammatic representation with illustrations of both types of fertilization–external and internal fertilization
Flowcharts
Develop flowcharts with illustrations of different approaches to reproduction– sexual vs. sexual reproduction and their respective events
Outline sexual reproduction events from pre-fertilization to post-fertilization.
Multimedia
Watch animations explaining different types of asexual reproduction in various organisms, such as amoeba using binary fission and hydra using budding.
Flashcards
- Types of asexual reproduction such as binary fission, budding, and vegetative propagation.
- Important terms related to sexual reproduction such as gametes, zygote, and fertilization.
- Major differences between processes of both external and internal fertilization.
Such tips and strategies help the students to deliver adequate reinforcement in understanding reproduction in organisms and, consequently, learn better for NEET examinations.
NCERT Exemplar Solutions Subject-wise link:
- NCERT exemplar solutions for class 12 Physics
- NCERT exemplar solutions for class 12 Chemistry
- NCERT exemplar solutions for class 12 Mathematics
- NCERT exemplar solutions for class 12 Biology
Types of Questions and Weightage on Reproduction in Organisms in Exams
The table given below indicates the weightage and types of questions asked from chapter Reproduction in Organisms in different exams:
| Exam Type | Types of Questions | Weightage of Reproduction in Organisms |
|---|---|---|
| CBSE Board Exams | Definitions, short answers on asexual and sexual reproduction, and examples | 5-7% |
| NEET | MCQs on reproductive processes, gametogenesis, and fertilization methods | 3-5% |
| Nursing Entrance Exams | True/False on reproduction types, scenario-based questions on reproduction in organisms | 2-4% |
| Paramedical Exams | Case studies on reproductive health and impacts of reproduction technology | 2-3% |
Prescribed Books for Reproduction in Organisms
The main and most recommended learning resource for reproduction in organisms is the NCERT Biology class 12 textbook covering all concepts as per the CBSE syllabus. For further understanding, "Trueman's Elementary Biology, Volume 2" can be referred to. The other useful book is "Pradeep's Biology" which is also known for its detailed explanation and plenty of solved examples. You can access a variety of videos, articles and mock tests on this chapter from the careers360 platform.
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Recommended Video on Reproduction in Organisms
Frequently Asked Questions (FAQs)
Animal classification is done based on whether the zygote growth occurs outside or inside the female parent. When laying eggs of fertilised or unfertilized eggs, the animals are referred to as egg-producing animals as reptiles and birds, and when they give birth to a young individual, they are called viviparous animals.
Prokaryotes are sexually transmitted by dividing cells or dividing them into parent plants. Special structures are made for plants such as runners, suckers, root crops, rhizomes and offsets that give birth to new offspring. It is also called vegetative propagation.
It incorporates the formation of gametes that combine to form the zygote (in the case of humans). It is a more complex and slow process than normal reproduction and most high-end animals reproduce in this way. Divided into pre-fertilization, fertilisation and post-fertilization.
Although reproducing sex requires two parents, it does not always have to be two different people.
Some organisms are usually called hermaphroditic which means that they contain both male and female gametes.
A living thing is capable of reproducing. There are two ways in which living things can produce their own copies: sexual reproduction and asexual reproduction. In a reproductive process, the male and female cells in the two parents combine to form a zygote that will eventually grow into a creature of their own.
Reproduction is the biological process by which organisms produce offspring, ensuring the survival and continuity of their species. It allows for genetic diversity and adaptation across generations.
Reproduction is the process through which living organisms generate new individuals. It can be categorized into asexual reproduction, where one organism produces clones, and sexual reproduction, which involves the fusion of male and female gametes.
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