Download ES Chapter 4 The Organization of Life

ES Chapter 4
The Organization of Life
Bellringer
Record this in your Ecolog
Today’s Objectives
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Distinguish between the biotic and abiotic
factors in an ecosystem.
Describe how a population differs from a
species.
Explain how habitats are important for
organisms.
I. Ecosystems:
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Everything is Connected
Ecosystem – all of the organisms living in an
area together with their physical environment
-oak forest, coral reef, vacant lot
Ecosystems themselves are connected to one
another
Ecosystems are communities of organisms and
their abiotic environment.
Examples are an oak forest or a coral reef.
Ecosystems do not have clear boundaries.
Things move from one ecosystem to another.
Pollen can blow from a forest into a field, soil can
wash from a mountain into a lake, and birds
migrate from state to state.
A. Components of an Ecosystem
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In order to survive, ecosystems need five basic
components – energy, mineral nutrients, water,
oxygen, and living organisms
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Energy for most ecosystems comes from the sun
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Ecosystem is like a car where all the hundreds of
parts that must work together for the car to run
-if any part doesn’t function, the entire system
may be affected
Ecosystems are made of both living and nonliving
things
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Classifying
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Biotic factors are environmental factors that are
associated with or results from the activities of living
organisms which includes plants, animals, dead
organisms, and the waste products of organisms.
Abiotic factors are environmental factors that are not
associated with the activities of living organisms
which includes air, water, rocks, and temperature.
Scientists can organize these living and nonliving
things into various levels.
Biotic Factors
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– the living and once living parts of an
ecosystem including all of the plants and
animals
-dead organisms, dead parts of organisms
like leaves, organisms waste products
-they interact with each other in various
ways
Abiotic Factors
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– the nonliving parts of the ecosystem
-air, water, rocks, sand, light, and
temperature
Living things are organized into various levels
– ecological organization
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Organisms are living things that can carry
out life processes independently.
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You are an organism, as is and ant, and ivy
plant, and each of the many bacteria living
in your intestines.
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Every organism is a member of a species.
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Species are groups of organisms that are
closely related can can mate to produce
fertile offspring.
Organization Of Living Things
4 Levels
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-Organism – an individual living thing
-Species – a group of organisms that are
closely related and that can mate and produce
fertile offspring
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Members of a species may not all live in the same
place
Organization Of Living Things
4 Levels
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Population – all the members of the same
species that live in the same place at the same
time
-in a population, its members usually breed
with one another rather than with members
of other populations
For example, bison will usually mate with
another member of the same herd, just as
wildflowers will usually be pollinated by other
flowers in the same field.
Organization Of Living Things
4 Levels
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Community – a group of various species that
live in the same place and interact with each
other
-a pond community – includes all the
populations of plants, fish, and insects that live
in and around the pond
-land communities are dominated by a few
species of plants, which in turn, determines
what other organisms live in that community
B. Habitat
Habitat – the place an organism lives
-every habitat has specific characteristics that
the organisms that live there need to survive
-if any of these factors change, the habitat
changes
-organisms are well-suited to their natural
habitats and cannot survive for long periods of
time away from them
Bellringer
Today’s Objectives
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Explain the process of evolution by natural
selection.
Explain the concept of adaptation.
Describe the steps by which a population of
insects becomes resistant to pesticide.
II. Evolution
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A. Evolution by Natural Selection
1859 – Charles Darwin observed that
organisms in a population differ slightly from
each other in form, function and behavior.
-some differences are hereditary
-he proposed the environment exerts a strong
influence over which individuals survive to
produce offspring
-some individuals because of certain traits are
more likely to survive and reproduce than
other individuals
Natural Selection
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-Natural selection – the unequal survival and
reproduction that results from the presence or
absence of certain traits
Darwin proposed that over many generations
natural selection causes the characteristics of a
population to change.
Natural Selection
Evolution
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Evolution – a change in the genetic
characteristics of a population from one
generation to the next
Nature selects for certain traits because
organisms with these traits are more likely to
survive and reproduce
Over time, the population includes a greater
and greater proportion of organisms with the
beneficial trait.
Adaptation
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Adaptation – an inherited trait that increases
an organism’s chance of survival and
reproduction in a certain environment
Other organisms, not just the environment can
cause a species to evolve.
-when two species evolve in response to
long-term interactions with each other is
called coevolution
B. Evolution by Artificial Selection
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Plants and animals that are cared for by
humans can exhibit artificial selection.
Artificial selection – is the selective breeding
of organisms by humans for specific
characteristics
The fruits, grains, and vegetables we eat were
also produced by artificial selection
Artificial Selection
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Many populations are domesticated.
Domesticated animals and plants have traits
that have essentially been controlled by
humans.
Look at Pg. 106 – selective breeding gives us
the dog breed we like – Chihuauah and wolf
are the same family Canis
Food is also selectively bred for sweetness
disease resistance and size
Evolution of Resistance
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Sometimes unwanted adaptations occur
Sometimes humans cause populations of
organisms to evolve unwanted adaptations.
Resistance – the ability of one or more
organisms to tolerate a particular chemical
designed to kill it
-the organism may contain a gene that allows it
to break the chemical down to harmless
substances Pesticide resistance
Pesticides
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-the few that survive a pesticide application reproduce
and pass the gene to their offspring
-each time the population is sprayed, the insect
population changes to include more and more
resistant members
-after many sprayings the entire population may be
resistant making the pesticide useless
The faster the organism reproduces, the faster its
populations can evolve.
Causes humans to want to develop more and more
toxic pesticides
Page 107 Fig. 11
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A pesticide sprayed on corn to kill
grasshoppers, for example, may kill most of
the grasshoppers, but those that survive happen
to have a gene that protects them from the
pesticide. These surviving insects pass on this
resistant gene to their offspring.
Each time the corn is sprayed, more resistant
grasshoppers enter the population. Eventually
the entire population will be resistant, making
the pesticide useless.
Insect Pesticide Resistance
Calculate % Change
Bellringer
Today’s Objectives
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Name the six kingdoms of organisms and identify
two characteristics of each.
Explain the importance of bacteria and fungi in the
environment.
Describe the importance of protists in the ocean
environment.
Describe how angiosperms and animals depend on
each other.
Explain why insects are such successful animals.
6 Kingdoms
6 Kingdoms
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Most scientists classify organisms into six kingdoms
based on different characteristics.
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Members of the six kingdoms get their food in
different ways and are made up of different types of
cells, the smallest unit of biological organization.
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The cells of animals, plants, fungi, and protists all
contain a nucleus. While cells of bacteria, fungi, and
plants all have cell walls.
A. Bacteria
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Bacteria – microscopic, single-celled
organisms that usually have cell walls and
reproduce by dividing in
half
-lack nuclei – prokaryotic cells
-two types of bacteria – archaebacteria and
eubacteria
-most bacteria that cause disease, found in
garden soil, etc. are eubacteria
-bacteria live in every habitat on Earth
H1N1 and antibiotics (virus)
Bacteria
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Bacteria play many important roles in the
environment
-break down remains and wastes of other
organisms and return the nutrients to the soil decomposers
-recycle mineral nutrients like nitrogen and
phosphorus
Bacteria
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-convert nitrogen in the air into nitrogen compounds
plants can use – nitrogen fixation
-nitrogen is important because it is a main component
of proteins and genetic material
-allow many organisms, including humans, to extract
nutrients from their food
Legumes – soybeans, locust trees, peas…..have a
symbiotic relationship with these bacteria
B. Fungi
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Fungus – an organism whose cells have
nuclei, cell walls, and no chlorophyll (pigment
that makes plants green)
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Mushroom is the reproductive structure of the
fungus, the rest is an underground network of
fibers which
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absorb food from decaying organisms in the
soil
Fungi
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Fungi play an important role in the
environment by breaking down the bodies and
body parts of dead organisms - decomposers
Some cause disease – like athlete’s foot
Give flavor to food – the blue in bleu cheese
Fungi called yeasts – produce the gas that
makes bread rise
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What kind of gas is released whem yeast ferment
sugars?
C. Protists
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Protists – a diverse group of organisms that
belong to the kingdom Protista
-some are animallike – amoebas while others
are plantlike – like kelp
-most are one-celled microscopic organisms
Protists
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-diatoms-float on the ocean surface
-Plasmodium-protist that causes malaria
-Algae is the most important protest – plantlike protists that use photosynthesis
-range from giant kelp to phytoplankton
D. Plants
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Many celled organisms that use photosynthesis
Eukaryotic
Have cell walls
Plants
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Most plants live on land where the resources a
plant needs are separated between the air and
the soil
-sunlight, oxygen and carbon dioxide in the air
-minerals and water are in the soil
Lower plants – first land plants -cannot grow
very large – mosses and ferns
Gymnosperms
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Gymnosperms – woody plants whose seeds
are not enclosed in fruit
-pine trees and other evergreens
-conifers – cone-bearing
Gymnosperms
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-have several adaptations that allow them to
live in drier conditions
-produce pollen – protects and moves sperm
between plants
-produce seeds which protect developing
plants from drying out
-needle-like leaves lose little water
-make much of our lumber and paper
Angiosperms
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Angiosperms – most land plants – produce
seeds in fruit
-grasses, flower producing plants
Angiosperms
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-depends on birds, bees and other animals to
distribute pollen and seeds
-most land animals are dependent on flowering
plants
-wheat, rice, beans, oranges, lettuce
-building materials and fibers like oak and
cotton
E. Animals
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Animals cannot make their own food – have to
take in all their food from the environment
Animal cells have no cell walls, so their bodies
are soft and flexible
Invertebrates
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Invertebrates – animals that lack backbones
-most live attached to hard surfaces in the
ocean and filter their food out of the water
-they move around as larvae – and are part of
the ocean’s plankton
-corals, worms, mollusks like clams and
oysters
-also squid and insects
Insects
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More insects exist on earth than any other type
of animal
-have a waterproof skeleton, move quickly,
reproduce quickly
-most can fly, small size allows them to live on
little food, hide from enemies
Insects
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Many insects and plants have evolved together
and depend on each other for survival
-insects carry pollen from male parts of
flowers to fertilize a plant’s egg which
develops into a fruit
-without insects we would not have tomatoes,
cucumbers, apples, and many other crops
Insects are also valuable because they eat other
insects that we consider to be pests
Insects
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Bloodsucking insects transmit diseases like
malaria, sleeping sickness, West Nile virus
Malaria and Plasmodium Click here
Do most damage by eating our crops
Vertebrates
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Vertebrates – animals that have backbones
-3 vertebrate groups – amphibian- toad, frog,
salamanders – lay eggs in water
Vertebrates
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reptiles – turtles, lizards, snakes, crocodiles –
lay eggs on land away from predators
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-cold-blooded
mammals – warm-blooded, have fur, feed
young milk
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being warm-blooded enables birds and mammals
to live in cold areas where others cannot survive
Memorization Tip