Transcript CHAPTER 4 The Organization of Life

CHAPTER 4
The Organization of Life
4-1 Ecosystems: Everything is
Connected
4-1 Objectives
• 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.
1. What is an ecosystem?
• All of the organisms living (biotic parts) in an
area together with their physical environment
(abiotic parts)
• EX: oak forest, coral reef, soil, wetlands,
desert
• Ecosystems do not have clear boundaries.
• Things move from one ecosystem to another.
Examples of Ecosystems
2. What are the components of an
ecosystem?
• In order to survive, ecosystems need five basic
components:
a)
b)
c)
d)
e)
Energy
Mineral nutrients
Water
Oxygen
Living organisms
• If one part of the ecosystem is destroyed or
changes, the entire system will be affected.
3. Where does most of the energy in
an ecosystem come from?
• The sun
4. What are the living or once living
things in an ecosystem called?
• Biotic factors
• EX: plants, animals, leaves, an organism’s
waste products
5. What are the nonliving parts of an
ecosystem called?
• Abiotic factors
• EX: air, water, rocks, sand, light, temperature
6. What are the levels of ecological
organization of living things?
a)
b)
c)
d)
e)
Organism
Population
Community
Ecosystem
Biosphere
Levels of Ecological Organization
7. What is an organism?
• One individual living
thing
• EX: a gorilla
• You are an organism, as
is an ant, an ivy plant,
and each of the many
bacteria living in your
intestines.
8. What is a species?
• A group of organisms that can mate and
produce fertile offspring, share common
genes and that resemble each other in
appearance, behavior, and internal structure
• EX:
humans - Homo sapiens
dogs – Canis familiaris
gorillas – Gorilla gorilla
9. What is a population?
• A group of individuals of the same species that
live in the same area and can interbreed
• EX:
bullfrog population of a pond
lion population of a savanna
bluebonnet population of a field
bacterium population of a petri dish
10. What is a community?
• A group of various species that live in the
same place and interact with each other.
• All the living inhabitants of an ecosystem
make up a community.
• EX: pond community – includes the
populations of all the different plants, fish,
insects, amphibians, and microorganisms that
live in and around the pond
• Land communities are often dominated by a
few species of plants.
• These plants then determine what other
organisms can live in that community.
Ecological Communities
11. How is a community different from
an ecosystem?
• A community includes only the biotic factors
whereas an ecosystem includes the biotic and
abiotic factors.
12. What is the biosphere?
• The layer around the Earth in which life occurs
naturally (extends from 8km above the Earth
to the deepest part of the ocean 8km below)
13. What is a niche?
• The way of life of an organism
• It is made up of the animals relationships with
its environment.
• EX: a lions niche is staking its territory, hunting
for zebras to eat, reproducing, etc.
14. What is a habitat?
• The actual place an organism lives.
• EX: a lions habitat is a savanna
• Every habitat has specific characteristics that
the organisms that live there need to survive.
If any of these factor change, the habitat
changes.
• Organisms tend to be very well suited to their
natural habitats. Animals and plants usually
cannot survive for long periods of time away
from their natural habitat.
4-2
Evolution
4-2 Objectives
• 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 pesticides.
1. Who is Charles Darwin?
• The “father of evolution”.
• He observed that organisms in a population
differ slightly from each other in form,
function, and behavior.
• Some of these differences are hereditary
(passed on from parent to offspring).
Charles Darwin
2. What did Darwin believe?
• Natural selection causes the characteristics of
a population to change over time.
• 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.
3. What is evolution by natural
selection?
• Natural selection – the process by which
individuals that have favorable variations are
better adapted to their environment so they
survive and reproduce more successfully than
less adapted individuals.
• Darwin proposed that over many generations,
natural selection causes the characteristic of
populations to change.
• Evolution is a change in the characteristics of a
population from one generation to the next.
Evolution by Natural Selection
4. What is an example of how nature
selects?
• Lions with sharp claws survive better than
lions with dull claws because lions with sharp
claws can get prey better.
• Over time, the population includes a greater
proportion of lions with sharper claws.
• As the populations of a given species change,
so does the species.
5. What is an adaptation?
• An anatomical, physiological, or behavioral
change that improves a population’s ability to
survive and reproduce in a certain
environment.
Nature Selects
6. What is coevolution?
• The process of two species evolving in response
to long-term interactions with each other.
• EX: the Hawaiian honeycreeper, which has a long
curved beak to reach nectar at the base of a
flower. The flower has structures that ensure
that the bird gets some pollen on its head.
• When the bird moves to the next flower, some of
the pollen will be transferred, helping it to
reproduce.
• The honeycreeper’s adaptation is
a long, curved beak.
• The plant has two adaptations:
– The first is the sweet nectar, which
attracts the birds
– The second is the flower structure
that forces pollen onto the bird’s
head when the bird sips nectar.
7. What is evolution by artificial
selection?
• Artificial selection is the selective breeding of
organisms, by humans, for specific desirable
characteristics.
• Dogs have been bred for certain
characteristics.
• Fruits, grains, and vegetables are also
produced by artificial selection.
8. What is the evolution of resistance?
• Resistance is the ability of an organism to
tolerate a chemical or disease-causing agent.
• An organism may be resistant to a chemical
when it contains a gene that allows it to break
down a chemical into harmless substances.
• Humans promote the evolution of resistant
populations by trying to control pests and
bacteria with chemicals.
Pesticide Resistance
4-3
The Diversity of Living Things
4-3 Objectives
• 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.
1. How many kingdoms are living
things classified into?
• Six kingdoms
• Their classification is based on differences in
characteristics.
DOMAIN
BACTERIA
ARCHAEA
EUKARYA
Kingdom
Eubacteria
(body)
Archaebacteria
(hot springs)
Protista
Fungi
Plantae
Animalia
Cell Type
Prokaryotic
(no nucleus)
Prokaryotic
(no nucleus)
Eukaryotic
(have a
nucleus)
Eukaryotic
(have a
nucleus)
Eukaryotic
(have a
nucleus)
Eukaryotic
(have a
nucleus)
Cell Structure
Cell Walls
Cell Walls
(cellulose)
Some have
cell walls
Cell
Walls
(chitin)
Cell
Walls
NO cell
walls
(cellulose)
# of Cells
Single Cell
(unicellular)
Single Cell
(Unicellular)
Mostly
unicellular
but some
multicellular
Mostly
multicellular
but some
unicellular
All
multicellular
All
multicellular
Nutrition
Auto or
Heterotrophs
Auto or
Heterotrophs
Auto or
Heterotrophs
(consumers)
Autotrophs
(producers)
Heterotroph
(consumer)
Examples
Known as the
“true bacteria”
E. Coli
Staph
Botulism
Dead Sea
Hot springs
Great Salt Lake
Found in extreme
environments
Algae
Amoeba
Puff balls
Conifers
Flowering
grasses
Mosses
Mammals
Heterotrops
Paramecium
Euglena
Mushrooms
Mold
Yeast
Arthropods
birds
Kingdoms of Life
2. What is the difference between a
prokaryotic and a eukaryotic cell?
• Prokaryotic:
– Do NOT have a nucleus or membrane bound
organelles
– EX: archaebacteria and eubacteria
• Eukaryotic:
– DO have a nucleus and membrane bound
organelles
– EX: fungi, protists, plants, animals
3. What are some characteristics of
bacteria?
• They are extremely small,
single-celled organisms
• Usually have a cell wall
• Reproduce by dividing in
half (asexual reproduction)
• Lack a nucleus (they are
prokaryotes)
• Bacteria live in every
habitat on Earth
4. What are the two main kingdoms of
bacteria?
• Archaebacteria – often
found in extreme
environments, such as
hot springs
• Eubacteria - most
common types of
bacteria, such as E. coli
5. Some facts about bacteria:
• Some types of bacteria breakdown the
remains are wastes of other organisms and
return the nutrients to the soil (they are
decomposers)
• Some types of bacteria recycle nutrients, such
as nitrogen and phosphorus.
• Certain bacteria can convert nitrogen from the
air into a form that plants can use.
• This conversion is important because nitrogen
is the main component of proteins and
genetic material.
• Bacteria also allow many organisms, including
humans, to extract certain nutrients from
their food.
• The bacterium, Escherichia coli (E. coli), is
found in the intestines of humans and other
animals and helps digest food and release
vitamins that humans need.
6. What are some characteristics of
fungi?
• Eukaryotic (have a nucleus)
• Have cell walls that act like mini-skeletons that
allow fungi to stand up right
• Do not contain chlorophyll (so do NOT carry
out photosynthesis)
7. What is a mushroom?
• The reproductive part of a fungus
• The rest of the fungus is an underground
network of fibers that absorb food from
decaying organisms in the soil.
8. Facts about Fungi:
• They are absorptive feeders – they get their
food by releasing chemicals that help break
down organic matter, then they absorb the
nutrients.
• The bodies of most fungi are huge networks of
threads that grow through the soil dead wood,
or other material on which the fungi is feeding
• Like bacteria, fungi play an important role in
breaking down the bodies of dead organisms.
• Some fungi, like some bacteria, cause disease.
EX: Athlete’s foot (caused by a fungus)
• Other fungi add flavor to food as in blue
cheese. The fungus gives the cheese both its
blue color and strong flavor.
• Yeasts are fungi that produce the gas that
makes bread rise.
9. What are some characteristics of
protists?
• They are mostly unicellular but include some
multicellular organisms.
• Some are animal-like (ameobas), some are
plant-like (kelp), and some resemble fungi.
10. Facts about Protists:
• Most are one-celled
microscopic organisms,
including diatoms, which
float on the ocean surface.
• Another protist,
Plasmodium, is the onecelled organism that causes
the disease malaria.
• From an environmental standpoint, the most
important protists are algae.
• Algae are plant-like protists that can make
their own food using the energy from the sun.
• Protists range in size from the giant kelp to the
one-celled phytoplankton, which are the initial
source of food in most ocean and freshwater
ecosystem.
11. What are some characteristics of
plants?
• Multicellular organisms that make their own
food using the sun’s energy (carry out
photosynthesis)
• Have cell walls
• Most plants live on land where they use their
leaves to get sunlight, oxygen, and carbon
dioxide from the air and use their roots to
absorb nutrients and water from the soil.
• Leaves and roots are
connected by
vascular tissue,
which has thick cell
walls and serves as a
system of tubes that
carry water and
food.
12. What is the difference between
gymnosperms and angiosperms?
• Gymnosperms – woody
vascular seed plants
whose seeds are NOT
enclosed by an ovary or
fruit.
– EX: conifers
(gymnosperms that bear
cones such as the pine
tree)
• Angiosperms –
flowering plants that
produce seeds within
fruit. Most land plants
are angiosperms.
– EX: Daylily
13. What are some characteristics of
animals?
• Cannot make their own food
• No cell walls so their bodies are soft and
flexible (some animals have evolved hard
exoskeletons)
• Animals are more mobile than plants.
• All animals move around in their environment
during at least one stage in their lives.
14. What are invertebrates?
• Animals that do not have backbones.
• Many filter their food out of water (corals,
worms, mollusks) (these are mobile in their
larval stage)
• Others move in search of food (squid, insects)
• There are more insects on Earth than any
other type of animal.
15. What are vertebrates?
• Animals that have a backbone.
• Include mammals, birds, reptiles, amphibians
and fish.