1dbiol - pp2 (life on earth) · 10/5/2014 3 earth’s spheres –the atmosphere earth’s...

10/5/2014

1

SNC1DBIOLOGY

SUSTAINABLE ECOSYSTEMS

L Life on Earth

(P.18-19)

Life on Earth

Of all the planets in the Solar System, Earth is the only one teeming withlife. Millions of organisms exist in countless habitats on the land and in thewater on our unique planet.

October 5, 2014 1DBIOL - Life on Earth 1

Diversity of Life on Earth

A habitat is the place where an organism lives. Terrestrial habitats arefound on land. Cacti and rattlesnakes live on land in arid (dry) deserts.Enormous trees with swarming insects live in tropical rainforests. Aquatichabitats are found in water. Colourful fish swim through the waters of theocean’s coral reefs. Frogs and crayfish live in small freshwater ponds. Butwhat features of Earth permit such a diversity of life to exist?

HABITAT

� place where an organism lives

� terrestrial habitat L land (desert, rainforest, …)

� aquatic habitat L water (coral reef, lake, …)


10/5/2014

2

Earth’s Spheres – The Biosphere

If you observed Earth from space, youwould see that Earth is surrounded by athin gaseous layer swirling with clouds –the biosphere. The biosphere is thepart of the planet, including all the water,land, and air, where life exists. It is verythin relative to the whole Earth. If Earthwere represented by a beach ball, thebiosphere could be represented by asheet of plastic wrap laid over it surfaceone layer thick.



The biosphere is the most important system on Earth because not only is itour home, but it is home to countless other organisms. Three maininteracting components make up the physical environment of thebiosphere. They are the atmosphere, lithosphere, and hydrosphere.



BIOSPHERE

� all the places on Earth (air, land, and water) where life exists

� 3 main components:

• atmosphere

• lithosphere

• hydrosphere


10/5/2014

3

Earth’s Spheres – The Atmosphere

Earth’s atmosphere is the thin layer of gasesthat surrounds the planet. It contains gasessuch as water vapour, oxygen, and carbondioxide that are necessary for living things.The atmosphere acts like a blanket wrappedaround Earth and prevents Earth from gettingtoo warm or too cool. The atmosphere alsoblocks some of the Sun’s radiation, which canharm organisms, including humans. Withoutthe atmosphere, life on Earth would not havebeen possible.


Earth’s Spheres – The Atmosphere

ATMOSPHERE

� thin layer of gases (H20, O2, CO2, ...) thatsurround Earth and support life

� prevents Earth from getting too warm/cold

� blocks the Sun’s harmful radiation (some)


Earth’s Spheres – The Lithosphere & Hydrosphere

The lithosphere is the rocky outer shellof Earth. It consists of the rocks andminerals that make up the mountains,ocean floors, and the rest of Earth’s solidlandscape.

LITHOSPHERE

� rocky outer shell of Earth


10/5/2014

4

Earth’s Spheres – The Lithosphere & Hydrosphere

The hydrosphere consists of all thewater on, above, and below Earth'ssurface. It includes oceans, lakes, ice,groundwater, and clouds.

HYDROSPHERE

� all of the Earth’s water in solid,liquid, and gas form

� oceans = 97%


Earth’s Spheres

NOTE!

All living things need space, water, andnutrients to survive. However, thesupply of these resources is limited.Ultimately, the availability of resourcesplaces a limit on the number ofindividuals of a species that can survive.All life on Earth is vying for access tothese resources.


Earth’s Spheres

LIFE ON EARTH

� all living things need space, water,and nutrients to survive

� the availability of these resourcescontrols the number of organisms


10/5/2014

5

U Check Your Learning

1. Unlike the moon (and other planetary bodies), explain how Earth’smass is related to its ability to have an atmosphere.

the gravitational attraction between Earth and the atmosphere (due toEarth’s mass) is large enough that Earth is able to hang onto it



2. How does the atmosphere help provide the conditions necessary for lifeto exist on Earth? (3 reasons)

• contains gases necessary for living things

• acts like a blanket to prevent Earth from getting too warm/cold

• blocks some of the Sun’s harmful radiation



3. Describe an extreme terrestrial habitat in Canada. Explain howorganisms are adapted to living there.

answers will vary from desert to tundra environments


10/5/2014

6


4. Of all the planets in the Solar System, Earth is the only one teemingwith life. But is there life elsewhere in the solar system?

we don’t know – a space probe nicknamed “Juice”, aimed at launchingin 2022, will spend at least three years studying Jupiter’s moons forsigns of life (i.e. several of Jupiter’s moons including Titan, Europa andGanymede seem to have properties that would support life, albeitbelow their icy surface)



TEXTBOOK

P.21 Q.9

WIKI (BIOLOGY)

O.... 1DBIOL - HO1 (Decomposer Lab) 7 see next slide!


Activity: Decomposer Lab (1DBIOL-HO1)

ISSUE

As you may remember, one of the most important characteristics ofscientific investigation is that scientists share their information – not onlythe evidence, but also the process by which evidence was obtained.However, most of you have not had very much (if any) experience with thisprocess. As such, we are going to perform and write up a practice formallab together (recall QHMMORCA).

INSTRUCTIONS

A. Obtain a copy of the handout 1PBIOL - HO1 (Decomposer Lab).

B. Read it, carefully!


1dbiol - pp2 (life on earth) · 10/5/2014 3 earth’s spheres –the atmosphere earth’s...

Documents