This document provides a lesson on the key characteristics of Earth that sustain life. It includes 10 multiple choice questions about these characteristics, such as the importance of the hydrosphere, composition of the atmosphere, and role of the ozone layer. It also discusses how Earth's temperature, presence of liquid water, atmospheric composition, distance from the Sun, energy source, magnetic field, nutrients, greenhouse gases, and tectonic plates create conditions suitable for life. The document emphasizes that precise combinations of these factors make Earth uniquely habitable in the universe.

1. Characteristics
of Earth that
Sustain Life Lesson 1.

2. Directions:
○Read carefully each item and
choose the letter of the correct
answer.

3. 1. Which of the following describes a habitable Earth?
A. has a weak magnetic field
C. dominant presence of solid ice
B. right distance from the Sun
D. presence of oxygen in the
hydrosphere
2.Which of the following is NOT one of the reasons why the hydrosphere is
important?
A. It sustains various life forms
B. It helps in regulating the atmosphere
C. It plays an important role in ecosystems
D. It plays a major role in the movement of tectonic plates
3. Which of the following is NOT a correct description of oxygen gas (O2)?
A. use by animals for respiration B. taken in by plants for photosynthesis
B. C. converted to carbon dioxide during respiration
C. . a colorless, odorless, tasteless gas essential to living organisms

4. 4. Which of the following describes a Goldilocks Zone?
A. a zone composed mainly of frozen water
B. a region where life is impossible to exists
C. a zone composed only of rocks and other celestial debris
D. an area where the temperature is not too hot and not too cold
5. Which of the following is an important characteristic of earth in sustaining life?
A. Earths’ position beyond the Goldilocks Zone
B. The atmosphere that blocks the rays of the sun from reaching Earth
C. The abundant nitrogen in the atmosphere made life possible on Earth
D. The presence of liquid water which plays a vital role for cell’s metabolism
6. Which of the following is the reason for the importance of Earth’s subsystems?
A. The subsystem influence Earth’s encounter with space objects.
B. The subsystems solely determine the survival of different organisms
C. The subsystems contribute scarcely in flow of matter and energy
D. The subsystems influence the climate, geological processes, and life on Earth

5. 7. Why is the ozone layer important in sustaining life on earth?
A. It is where Earth satellites orbit and auroras show.
B. It influences hydro-meteorological phenomenon such as storms.
C. It shields the Earth the Sun's ultraviolet radiation and keeps the planet warm.
D. It is where celestial objects get burned and disintegrated upon entering
Earth.
8.Which subsystem helps regulate the temperature of the Earth so we do not
experience too much hotness or coldness.
A. Biosphere B. Lithosphere C. Atmosphere D. Hydrosphere
9. Which subsystem do bodies of water surround the Earth a part of?
A. Hydrosphere B. Geosphere C. Biosphere D. Atmosphere
10.In which subsystem are gases such as oxygen gas, water vapor, and
nitrogen gas found?
A. Hydrosphere B. Geosphere C. Biosphere D. Atmosphere

6. Directions:
The picture in each item depicts a
certain characteristic of Earth as a planet
of life. Fill in the missing letters to form the
words or phrases implied. Analyze each
picture and given clue letters to answer
this activity.

12. A. Fill me In.
Directions
WRITE the word within the parenthesis ( ) that
best completes each statement. (20 points)

13. Some characteristics of (Earth, Venus) that allow it to sustain life is the
oxygen (rich, poor) atmosphere and (polar ice cap, liquid water, water
vapor) that is located on the surface of the earth. Both oxygen and water are
the (keys, not necessary) to life as we know it. Oxygen is used by (animals,
plants) during aerobic (respiration, fermentation). Oxygen is (essential, not
needed) for animals to adhere to their basic needs. Surface (water, ocean) is
also a basic need for all living things. Water keeps all living things (hydrated,
dry) as well as help control the (climate, weather) which affect each
organism’s survival. Earth is surrounded by a (thin, thick) atmosphere that
contains nitrogen, oxygen, and other (trace, tiny) gases. This atmosphere
provides the (air, fumes) that we breathe. It also helps to (regulate, estimate)
the temperature so that we do not experience extreme (hot or cold, good or
bad). Earth’s atmosphere also contains a layer of (ozone, helium) a molecule
consisting of three oxygen (atoms, molecules) which provides protection from
harmful solar (radiation, eclipse). Finally, threequarters of Earth's surface is
covered by (water, oxygen) a necessary ingredient for life. Earth is the only
(planet, heavenly body) in the solar system that contains liquid water.

14. B. TRUE or FALSE
Directions:
Write TRUE for statements that describes the uniqueness of Earth
and FALSE if otherwise. Write your answers in sheet of paper.
1. Presence of oxygen in the atmosphere has no effect on
the Earth’s life forms.
2. There is a continuous flow of energy within the Earth’s
system.
3. Earth’s water is in the form of ice and is readily available
for organisms.
4. The energy of the sun drives all life processes on Earth.
5. Earth is positioned in the Goldilocks zone.

16. Goldilocks & the 3
bears
○Remember the story of Goldilocks & the 3
bears.
.

17. ○What are some conditions
that are “just right” on Earth
to allow life to exist?

18. Just Right….
○A habitable planet has abiotic factors
(non-living) and characteristics that are
just right for allowing life to exist.
○Earth is the only known planet at this time.

19. Characteristics that Allow
Life to Exist:

20. 1. Temperature
○ Because of its distance from the sun, Earth has a
temperature range of 0°C to100°C, which allows life
to exist.
○ Life is limited to a temperature range of -15°C to
115°C.(At about 125°C, protein and carbohydrate
molecules, and the genetic material (e.g., DNA and RNA)
start to break apart.)
○Given this temperature range, H2O may still exist
in liquid form being crucial to life.

21. 2. Presence of Liquid
Water
○ It contains the oxygen needed
for life
○ This matter dissolves and
transports materials in and out
of the cell.
○ Landforms allow water to run from high to low
elevations and replenish as the seasons change.

22. Composition of Atmosphere
○The Earth’s atmosphere thickness
traps heat & protects it from the
Sun’s harmful UV radiation.
○It also protects it from small to
medium sized meteorites.
○It contains gases including nitrogen,
oxygen, argon, & carbon dioxide.
(NOArCO2)

23. *The Ozone Layer
○ prevents most of these dangerous UV
rays from reaching the surface
○ situated in an area known as the
stratosphere (starts at between 10 to 17
kilometres from Earth's surface and
extends up to 50 kilometres high)
○ able to absorb most ultraviolet
radiation so prevents it from reaching
the surface

24. 3. Right Distance from the
Sun
○ Earth is in the Goldilocks Zone.
○ A region with the just the right temperature to sustain life – not too
cold not too hot.
Sun Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune

25. 4. Energy Source
○ With a steady input of either light or chemical energy
from the sun, cells can perform the chemical reactions
necessary for life (photosynthesis
○ With the availability of sufficient energy, organisms can
perform different metabolic reactions through the cells.

26. ○It shields us from the
electromagnetic radiation
coming from the Sun.
○The magnetic field deflects
the radiation that may
destroy the ozone layer.
○ Planets need protection from solar wind
5. Strong Magnetic Field

27. ○Planet must have molten metal interior
○Earth has solid metal core with liquid outer core, causing
magnetic field.

28. 6. Nutrients
○ All solid planets and moons have the same general chemical
makeup so nutrients are present.
○ Planets with a water cycle or volcanic activity can transport and
replenish the chemicals required by living organisms (vitamins).

29. 7. Greenhouse Gases
○Without the greenhouse
effect, Earth would be frozen,
more than 60º F colder.
○Atmosphere is capable of
trapping heat because of
greenhouse gases.

30. 8. It is protected by the plate tectonics
from the very hot temperature of the
core
○The earth’s core causes the
convection currents in the mantle
causing the overlaying lithosphere
to move.
○However, the surface is protected
from heat from the core by the
lithospheric plates.

32. Learning Tasks
○Pp 7, 8, & 9 in the module

34. Review Questions
1. What characteristics are needed for life
to exist?
2. Why is Earth the perfect place for life to
exist?