CBSE Class 10 Science Notes Chapter 8 How do Organisms Reproduce

CBSE Class 10 Science Notes: Chapter 8 – How do Organisms Reproduce?

Key Concepts

Reproduction:
- The process by which organisms produce offspring for the continuity of species.
- Types:
  - Asexual Reproduction: Single parent, identical offspring.
  - Sexual Reproduction: Two parents, genetic variation.
Asexual Reproduction Methods:
- Fission: Binary (e.g., bacteria), Multiple (e.g., Plasmodium).
- Fragmentation: Breaks into fragments (e.g., Spirogyra).
- Budding: Growth of a new organism from a bud (e.g., Hydra).
- Vegetative Propagation: Through stems, roots, and leaves (e.g., potato, bryophyllum).
- Spore Formation: Formation of spores (e.g., Rhizopus).
Sexual Reproduction in Plants:
- Flower Structure:
  - Male: Stamen (anther, filament).
  - Female: Carpel (stigma, style, ovary).
- Pollination:
  - Self-pollination: Within the same flower.
  - Cross-pollination: Between different flowers.
- Fertilization: Fusion of male and female gametes in the ovary.
- Formation of seeds and fruits.
Sexual Reproduction in Humans:
- Male Reproductive System: Testes, vas deferens, urethra, penis.
- Female Reproductive System: Ovaries, fallopian tubes, uterus, vagina.
- Fertilization: Occurs in fallopian tubes, zygote forms, and implants in the uterus.
- Menstrual Cycle: Monthly cycle, that prepares the body for pregnancy.
Importance of DNA Copying:
- Ensures the transfer of genetic material.
- Introduces variation for adaptation.
Contraceptive Methods:
- Physical Barrier: Condoms.
- Chemical Methods: Pills.
- Surgical Methods: Vasectomy, tubectomy.

Key Diagrams:

Human reproductive systems (male and female).
Flower structure showing reproductive parts.

Most Important Science Class 10 Questions Answers For Board Examination

Here are some of the top most asked questions from Chapter 8, How do Organisms Reproduce, in the last 5 CBSE Class 10 board exams:

What is the significance of reproduction in living organisms?
- Reproduction ensures the continuity of species and genetic variation.
Describe the process of fertilization in humans.
- Fertilization occurs when the male sperm cell fuses with the female egg cell in the fallopian tube, forming a zygote.
Differentiate between sexual and asexual reproduction.
- Sexual reproduction involves two parents, leading to genetic variation, while asexual reproduction involves one parent, producing identical offspring.
What are the different methods of asexual reproduction?
- Methods include fission, fragmentation, budding, vegetative propagation, and spore formation.
What is pollination? Explain its types.
- Pollination is the transfer of pollen from the male anther to the female stigma. It can be self-pollination or cross-pollination.

Most Important MCQs Science Class 10 For Board Examination

Here are some MCQs based on Chapter 8: How do Organisms Reproduce:

Which of the following is asexual reproduction?
a) Budding
b) Fertilization
c) Pollination
d) Regeneration
In humans, fertilization occurs in which part of the female reproductive system?
a) Ovaries
b) Uterus
c) Fallopian tube
d) Vagina
What is the main advantage of sexual reproduction?
a) No need for a mate
b) Genetic diversity
c) Rapid population growth
d) Clonal offspring
Which of the following is not a method of vegetative propagation?
a) Cutting
b) Grafting
c) Binary fission
d) Layering
What is the primary function of the stigma in a flower?
a) To produce pollen
b) To attract insects
c) To receive pollen
d) To protect the ovary