Page 195 - Innovator's Science-8

Protecting life on Earth is a shared responsibility. From individuals and
communities to world leaders, everyone has a part to play. By making smart

choices and working together, we can keep Earth healthy and ensure it
remains a safe and vibrant home for generations to come.

Know Your Scientist
Often called the “father of modern climate science”, Dr James Hansen was one of the first scientists to warn
the world about global warming. In 1988, he presented clear evidence before the U.S. Congress showing that
Earth's temperature was rising because of greenhouse gases. His pioneering research inspired global
agreements like the Kyoto Protocol and the Paris Agreement Hansen continues to advocate for urgent climate
action and cleaver energy solutions.

Grasp-Up

Habitable Zone: The region around a star where condi ons allow liquid water to exist.
Greenhouse Effect: The process by which gases trap heat in Earth's atmosphere.
Biosphere: The zone of life on Earth, including land, water, and air.
Sexual Reproduc on: Reproduc on involving two parents resul ng in gene c varia on.
Asexual Reproduc on: Reproduc on from a single parent with iden cal offspring.
Gametes: Reproduc ve cells (sperm/pollen and egg/ovule).
Fer lisa on: Fusion of male and female gametes to form a zygote.
Vegeta ve Propaga on: A type of asexual reproduc on in plants using roots, stems, or leaves.
Magne c Field: Earth's magne c shield that protects from harmful space radia on.
Geodiversity: Natural variety of landforms, soils, and rocks that support life.

Points to Reflect
• Earth is the only known planet to support life due to its perfect position, size, atmosphere, and magnetici
field.
• Life exists on a thin outer layer (crust) of Earth.
• Earth's atmosphere, magnetic field, and water cycle sustain life by maintaining balance.
• Reproduction ensures the continuity and diversity of life through genetic transfer.
• Two types of reproduction exist: asexual (identical offspring) and sexual (diverse offspring).

NCERT Textbook Questions (Solved)

Let Us Enhance Our Learning
1. What is one major reason Mars cannot currently support life like Earth?

i. It has too many volcanoes.
ii. It is too close to the Sun.
iii. It lacks a thick atmosphere and liquid water.
iv. Its magne c field is too strong.
Ans. ii. It lacks a thick atmosphere and liquid water.

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