Transcript Chapter 4 ppt (1)x

Chapter 4
Starts the Ecology Unit
The study of Ecosystems
1. Everything is Connected
2. How things Evolve Over time
3. The Diversity of Living Things
4-1 Everything is Connected
Learning Targets
1. Distinguish between the biotic and
abiotic factors in an ecosystem.
2. Describe how a population differs from a species.
3. Explain how habitats are important for
organisms.
4. Give examples of how organisms are
interconnected
Make a list about how these 2
ecosystems are the same
• When a leaf drops from a tree into a stream
• Decomposers (bacteria & fungi) start the break
down
• Stream insects eat the decomposers
• Shredder insects (mayflies) physically break down
the leaf
• Collector insects (caddisflies) may catch and eat it
from the stream water flow
• Algae and river plants used the dissolved
nutrients
• Predator insects eat original insects then birds
eat the predator
• Bird droppings provide nutrients to help tree
make new leaves.
Ecosystem
• All of the organisms
living in an area
together with their physical environment.
• There aren’t clear boundaries. Ex. Organisms
wander between forest and field.
• Biotic factor=living or once living. Ex. Plants,
animals, leaves, waste products
• Abiotic factor=non-living parts. Ex water,
rocks, sunlight, temp.
Survival Needs
of Ecosystems
• Energy-start with the
sun for MOST
• Nutrients, carbon dioxide, oxygen, water
• Living organisms-plants
• If one part of the system changes, it will
change another part b/c the “parts” are
connected (like leaf ex.)
Definitions
• Organism= one individual thing. One ant
• Species=group of organisms that can mate to
produce fertile offspring (babies later make
babies)
• Our species : Homo sapiens
• Population=all members of same species in
one area-members usually breed with each
other, not other populations in another area
Definitions. cont.
Communities= groups of populations. Ex.
Squirrels, mice, birds, worms, ants.
It’s all the biotic parts whereas ecosystems
include abiotic parts.
Land communities are characterized by the kind
of plants (oak trees), which then help
determine the kinds of animals
(squirrels)
Habitat
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Where an organism lives
Salamander-damp forest
Cactus- desert
Clown fish -coral reef
Mouse-forest-field
Organisms tend to be well
suited to their environment.
If they aren’t, then likely they
will become extinct.
What if the environment changes? 
Totally connected
Energy Transfers in Food Webs
• Tertiary (or 4th)
consumers
• Secondary
consumers
• Primary
consumers
• Producers
What happens to prey #s when
predator #s go up and down?
4-2 Evolution
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Learning Targets
Explain the process of evolution
Explain the concept of adaptation
Describe the steps by which a population of
insects becomes resistant to a pesticide
• Success criteria: produce a brochure or poster
depicting 3 adaptations for 1 organism of
your choice and describe how they help
survival
Describe how a squirrel is well suited
to live in this environment.
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Fur (for cold weather)
Eat pinecone seeds, acorns (variety of food)
Hides food for winter when food is scarce
Good balance, stays in trees for (protection)
Builds nest high in tree for (protection)
How is it NOT well suited?
Forgets where nuts are hidden
Run over by cars?
How do you get to be well suited?
• Environment exerts a strong influence over
which organisms survive to produce offspring
• Having certain TRAITS make it more likely for
an organism to survive (and then reproduce)
• NATURAL SELECTION=the unequal survival of
organisms with particular traits
• Over many generations natural selection
caused populations to change
Idea of natural variation
• Those with the BEST traits (for where they live)
survive to reproduce.
Evolution=
• A change in the genetic characteristics of a
population from one generation to the next.
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1. different color fur
2. fur color is genetic
3. Many squirrels born, best suited survive.
4. Best trait squirrels have babies like them. That
trait becomes more common. Those that died
can’t pass along their traits.
Read case study 104-5
Deer example from book pg 105
• Adaptation=an inherited trait that increases
and organisms survival and reproduction in a
CERTAIN environment
• (each environment may exert a different kind
of pressure: more fur, or less fur elsewhere
Co-evolution=
• Organisms evolve adaptation to other organisms
and to their physical environment-in this case the
process of two species evolve in response to long
term interactions with each other
• Hawaiian Honeycreeper beak, long and curved to
reach into the long, curved Lobelia flower
• The flower has evolved structures that make the
bird wear its’ pollen and release it when it sips
from another Lobelia. (allows for greater
pollination )
• 2 adaptations-sweet nectar, shape of flower
Artificial Selection and Evolution
• Selective breeding done by humans
• Choose the seeds from the best crops for next
year
• Choose Cows that produce more milk and
breed them
• Large change over 100 years
• CORN-Since the practice of agriculture began, 8-10K
years ago, farmers have been altering the genetic
makeup of the crops they grow. Farmers selected the
best looking plants and seeds and saved them to plant
for the next season. Then, once the science of genetics
became better understood, plant breeders used what
they knew about the genes of a plant to select for
specific desirable traits to develop improved varieties.
• Features such as faster growth, higher yields, pest and
disease resistance, larger seeds, or sweeter fruits has
dramatically changed domesticated plant species
compared to their wild relatives. For example, when
corn was first grown in N & S America, thousands of
years ago, the corn cobs farmers harvested were
smaller than one’s little finger. Today, there are
hundreds of varieties of corn, some of which produce
cobs as long as one’s forearm.
Evolution and Resistance
• Resistance is the ability of one or more
organisms to tolerate a particular chemical
designed to kill it. How?
• A gene that allows the chemical to be broken
down ( A few organisms have this and that
new population grows and is resistant)
• The new population has less competition for
food and space and will thrive
• Bacteria have done this with antibiotics
Figure 11
Quick example of resistance
The Diversity of Living Things
• Learning targets
• Name the 6 kingdoms +Place organisms into
kindgoms
• Explain the importance of bacteria and fungi in
the env. Describe the importance of protists in
the ocean
• Describe how angiosperm and animals depend
on each other
• Explain why insects are such successful animals
Evolution allowed this to happen
Classification is based on
• How you eat?
• How many cells are you made of?
• Do you have a nucleus and membrane bound
organelles?
• Do you have a cell wall? What’s it made of?
The 6 kingdoms and their
characteristics- know basic idea
Importance of Bacteria
• Break down wastes and return it to env.
• Recycle minerals and nutrients like nitrogenconvert nitrogen in air (N2) to a form plants
can use
• Help organisms like humans
digest food and extract
nutrients & vitamins from
our food. Ex. E. coli in our
colon
Importance of Fungi in
env.
• Fungus, ex. mushroom: has
a
underground network of fibers
• They absorb food from decaying organisms in
soil and elsewhere-therefore they help break
down dead stuff –considered
one of the two decomposers
(bacteria is the other)
• Also make bread rise, add CO2
and alcohol in beer
The importance of
ocean protists
• Initial source of food in an
ocean…. Algae, photosynthesize= create food
• But too much causes “scum” on water and
can lead to all fish dying in small waterways
• Other kinds of protists include: amoeba ,
diatoms
Plants
• Gymnosperms=pine tree and evergreens
• Seeds are NOT enclosed in a fruit
• Seed protects the developing
plant
from drying out (adaptation)
• Needles on trees shed
snow (adaptation)
Plants
• Most land plants
• Flower is the reproductive structure
• Pollen: flies on wind, is carried by insects
feces.
• Most of the food we eat comes from
flowering plants: wheat, rice, beans.
• grains often have small, unattractive flowers
pollinate with wind
• Many plants depend on animals to
disperse seeds or pollen
• Animals eat the food and
use plants to build homes
or
How do plants and animals depend on
each other???
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Answer question
Food
Shelter- our houses are build of wood
Spreading seeds around.
Animals-have to eat-move around at
some point in their lives
• Insects
• Worms
• Mammals
• Coral
• Clams
Invertebrates- have no backbone-insects-worms
Vertebrates- have a backbone-humans-birds frogs
cicada
Why are insects successful?
Insects make up the largest group
of animals
• Waterproof external skeleton-don’t dry
out
• Reproduce quickly
• Small size, need only a little food & little space
to hide
We depend on insects because
• They pollinate many of the foods we eat like
tomatoes
• Eat other insects we call pests
• We don’t like insects because
they eat our food and can transmit diseases ex. Malaria, West Nile virus, EEE
For us-they pollinate much of the food we eat
Can transmit Also eat our crops