Transcript Power Reviews PPT

Spring Final Exam Review
2014
Evolution

Charles Darwin said that
evolution occurred due to
Natural Selection.
Evolution = change in a
POPULATION over time
Natural Selection occurs due to:
a.
Variation exists in nature
b.
More offspring are produced than will survive
c.
There is a constant struggle for survival
d.
Some individuals in the species will have variations that
cause them to be the most fit in a particular
environment.
e.
Vast amount of time is required for a species to
change
Sources of Genetic Variation
 The two main sources of genetic variation are:
 The individual does not evolve; the population evolves
1. Mutations – Any change in a sequence of DNA.
Can occur because of mistakes in the replication of DNA or as a
result of radiation or chemicals in the environment.
A “helpful mutation increases fitness of the individual in its
environment, where as a “harmful” mutation decreases fitness.


2.
Recombination - The natural formation in offspring of
genetic combinations not present in parents.


Crossing over during meiosis further increases variation.
The frequency of the mutated gene will increase if it is a helpful
mutation
Evidence to Support Evolution
 What are adaptations?
 Physical or behavioral traits that helps an
individual survive & reproduce in its
environment.
 The long neck of a giraffe is an example of an
adaptation.
 Fossil Records
 Fossils in lowest sedimentary rock layers are
older and simpler than fossils found in higher
layers of rock.
 Example of Relative age dating
 The youngest and most complex fossils are found in
the top layers of rock.
Evidence of Evolution
comes primarily from these sources….
1.
2.
3.
4.
5.
Fossil record
Geographical distribution of related species
Structural similarities of related life forms
Chemical similarities in DNA
Embryology
Evidence to Support Evolution

Homologous Structures

Similar structures but different functions

Whale’s flippers and humans arms are examples of
homologous structures.


Vestigial Structures

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Show evidence of a common ancestor
structures or organs that are reduced in size; do not
seem to serve a useful function
Hip bones in whales and snakes are examples of
vestigial organs because they serve no function.
Analogous Structures


Similar structure, similar function
Originated from different embryological structures

Example: Wing of an insect and wing of a bird
Evidence to Support Evolution

Similarities in Embryology
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
The embryos of vertebrates are very
similar during early development.
Common cells & tissues growing in
similar ways produce homologous
structures.
The same groups of embryonic cells
develop in the same order and in similar
patterns to produce tissues & organs.

All vertebrate embryos are alike in that they all have similar
patterns of development, especially in the very early stages,
which suggests a common ancestor.
Label Each Type of Evidence for Evolution
A
C
B
D
3 Types of Natural Selection:
1.
2.
3.
Directional Selection
Disruptive Selection
Stabilizing Selection
Directional Selection
By favoring either of the extreme forms of a trait,
directional selection can lead the one population
to evolve into a new species.
Disruptive Selection
In this type, both extreme forms of a trait are favored. In
some cases, there may be no intermediate forms, which can
lead to the evolution of two new species. (Speciation
occurs)
Stabilizing Selection
This type of natural selection favors average
individuals. In this way, variation in a population is
reduced. Evolution does not occur.
Stabilizing Selection
Low mortality,
high fitness
High mortality,
low fitness
Selection
against both
extremes keep
curve narrow
and in same
place.

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__ B _a a. Does not lead to speciation or evolution.
__ C _ b. Cause one species to evolve into two different
species.
__ A __ c. Causes one species to evolve into a different
species.
__ A _ d. Type of selection that favors one extreme
variation.
__ B _ e. Type of selection that favors the average
variation.
__ C _ f. Type of selection that favors the two extreme
variations.
Genetic Drift
 Natural selection is not the
only source of evolutionary change. In small
populations, an allele can become more or less
common simply by chance.
 Genetic Drift - Random change in allele frequencies that
occurs in small populations.
 The smaller a population is, the farther the results may be from what
the laws of probability predict.
 Unlike natural selection because:
1. It happens by chance - such as random mating or a natural
disaster (fire, landslide or lightning strike).
2. Doesn’t work to produce adaptations like natural selection
does.
How does Geographic and Reproductive
isolation lead to speciation?
 Geographic isolation: a barrier that physically separates
members of a species into two or more groups.
 Members of an original species can no longer breed
together to produce fertile offspring so they are
reproductively isolated and now 2 species.
Behavioral Isolation
 2 species do not breed due to behavior
 Female meadowlark only responds to mating call of males that are
like them
 Blue-footed boobies perform elaborate dance to show off blue feet.
Helps identify himself to female as a potential mate.
 Male fireflies signal to females by flashing their lights in specific
patterns. Females only respond to signals flashed by own species
(keeps them from mating with other closely related firefly species)
Survival of the fittest and Genetic
Equilibrium
 Nature selects (Natural selection) those individuals w/
favorable traits to leave more offspring that are better suited
(FIT) for their environment
 Genetic Equilibrium
 when no change takes place.
 What must occur in order for allele frequencies to remain
constant?
 Random mating, no mutations, no movement into or out of population
and no natural selection
Why do we classify organisms?

1. Why Classify?
a. To study the diversity of life
b. To group organisms according to shared
lines of evolutionary descent
2. Why are organisms given scientific names?
a. Common names are misleading
jellyfish
silverfish
star fish
None of these animals are fish!
Cladograms

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Diagram used to show the evolutionary
relationships among groups of organisms
The more derived characteristics the organisms
have in common, the more closely related they are.
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Which letter designates the most recent common
ancestor of the ant and grasshopper? C
The traits on the lines are called – derived
characters
Give the number of where would you place the
trait “doubled wing pairs” 2
Which letter designates the most recent common
ancestor of all of the organisms shown? A
Which organisms would have the most similar
DNA? The butterfly and dragonfly or spider and
caterpillar? Butterfly and dragonfly
Binomial Nomenclature


Created by Linnaeus
Allowed scientists to give each organism a universally
accepted two-part name
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
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In order to avoid confusion
The first part is the Genus; the second part is the Species
EX – “Homo sapiens”

“Homo” is the Genus, and “sapiens” is the species
The 5 Rules of Nomenclature:
1.
2.
3.
4.
5.
The Genus is a noun and is CAPITILIZED
The species is an adjective and is lowercase
If writing by hand underline each word separately
If typing the name italicize it
If used repeatedly first write it fully out, then you can
abbreviate the Genus
(Ex. H. sapiens)
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Kingdom (most general)
Phylum
Class
Order
Family
Genus
Species (most specific)
Classifications
King Philip
came over for
good sweets!
If the horse and zebra are in the
same Order, what other
classification levels do they have
in common?
Kingdom, Phylum, & Class
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Cell Type: none bc not a
cell
Cell wall: not a cell just a
capsid (protein coat)
Body Type: noncellular
Nutrition: N/A
Reproduction:
Replication requiring a
host cell
Examples: influenza and
HIV
Viruses are Highly Specific
 HIV
infects Helper T cells– part of the
immune system.
 Different cold viruses attack the cells lining
the nose and sinuses.
 Antibiotics are not effective against viruses.
 Viruses can cause changes in a cells DNA
which can lead to cancer (uncontrolled cell
growth—mitosis)
Lytic vs. Lysogenic Replication
 Two


methods of virus replication
Lytic and Lysogenic
Both result in the host cell being destroyed
and more copies of virus being released
 Lytic
Replication– virus enters a cell,
makes copies of itself, and causes the cell
to burst relatively quickly
 Host cell is lysed and destroyed.
1. Virus attaches
3. New viral proteins and
genetic material are made
2. Virus injects genetic
information into host
4. Viral parts are
assembled
5. New viruses are released as host cell lyses (bursts) and is destroyed.

Lysogenic Replication–
◦ Virus integrates its genetic information into the
DNA of the host cell
◦ Viral genetic information replicates along with the
host cell’s DNA for a relatively long period of time
Vocabulary to remember
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Prokaryote: lacks a nucleus
Eukaryote: contains a nucleus
Unicellular: contains one cell only
Multicellular: contains two or more cells
Autotroph: makes its own food
Heterotroph: must consume food
Kingdom Archaebacteria: Live in
Extreme Habitats
Classification of Living Things
Domain
Archaea
Kingdom
Archaebacteria
Cell Type
Prokaryotic
Cell Structures Cell walls do not
have peptidoglycan
Number of Cells Unicellular
Nutrition
Autotroph or
heterotroph
Examples
Methanogens
Halophiles
Thermophiles
Bacillus infernus lives in deep
sea vents in the ocean –
obtains energy from Earth’s
heat
Kingdom Eubacteria
Classification of Living Things
Domain
Bacteria
Kingdom
Eubacteria
Cell Type
Prokaryotic
Cell Structures Cell walls have
peptidoglycan
Number of Cells Unicellular
Nutrition
Autotroph or
heterotroph
Examples
Streptococcus,
Escherichia coli
:
E-coli bacteria (yellow)
on the head of a needle.
Streptococcus
Shapes of Bacteria
Bacteria that are spherical shaped are
called coccus (cocci)
Bacteria that are rodlike are
called bacillus (bacilli)
Bacteria that are spiral shaped
are called spirilli
How to Treat Bacterial Infections

Antibiotics - Compounds that block the growth and
reproduction of bacteria
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To make sure that you get the right treatment, your doctor
may take a sample (a swab from the throat or a urine sample)
Do not take antibiotics if you don’t have a bacterial infection.
You are only making the bacteria smarter and more resistant!
Bacteria
Bacteria are helpful and harmful organisms
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Helpful:
1.
2.
3.
4.
5.
6.

Cheese, pickles, yogurt, and vinegar are produced as the results of
metabolism by certain bacteria
Clean up oil spills
Aids in human digestion (E. coli) and other life processes
Carry out photosynthesis
Decomposers (recycle nutrients)
Fix Nitrogen (bacteria live on plant roots & turn nitrogen in air
into forms that plants can use to make proteins)
Harmful:
1.
2.
Some bacteria cause disease (~½ of all human diseases are caused
by bacteria)
Pathogen – Disease causing agent
Kingdom Protista
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Cell Type: Eukaryotic
Cell wall: Cellulose (some)
Body Type: Unicellular and Multicellular
Nutrition: Autotrophic and Heterotrophic
Are Mobile (can move around)
Examples: paramecium, euglena, algae
What is a Protist?
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Kingdom Protista = “Junk Drawer” Kingdom
Protists are eukaryotes that are not members of the
Kingdoms Plantae, Animalia, or Fungi.
Prefer to live in moist, aquatic conditions
Classified according to their mode of nutrition:
 Heterotrophic (animal-like)
 Autotrophic/Photosynthesis (plant-like)
 External digestion (fungus-like)
Commonly classified As: protozoa, ameoba, paramecium
Types of Animal-like Protists
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Zooflagellates
- Swim using a flagella
Sarcodines
- use pseudopods for feeding and movement (amoeboid
movement
- ex. amoebas, foraminiferans, heliozoans

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Ciliates
- use cilia for movement and feeding
Sporozoans
-
Do NOT move on their own; are parasitic
Sporozites can attach themselves to their host and then live
within the host as a parasite
Plant-Like Protists
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Unicellular & Multicellular Algae
Produce their own food by photosynthesis=Autotrophs
Classified by color
Fungus-Like Protists
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Like fungi, the fungus-like protists are heterotrophs (lack
chlorophyll) that absorb nutrients from dead or decaying
organic matter. But unlike most true fungi, fungus-like
protists have centrioles.
They also lack the chitin cell walls of true fungi and are
able to move at some point in their lives.
Reproduce by forming spores
EX: cellular slime molds, the acellular slime molds, and the
water molds.
Kingdom Fungi
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Cell Type: Eukaryotic
Cell wall contains Chitin
Body Type: Unicellular and Multicellular
Nutrition: Heterotrophic
Are Immobile (cannot move around)
Examples: yeast, morel, earthstar puffball, bread mold
(Rhizophus stolonifer), mushrooms
The Kingdom Fungi
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Eukaryotic heterotrophs that have cell walls
Plant-Like but without chlorophyll
Can be either
1. Parasite- Feeds on living organisms
2. Saprophyte- Feeds on dead or decaying matter
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The cell walls are made up of chitin
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A complex carbohydrate; also found in insect exoskeletons
Classified based on sexual reproductive structure- they
reproduce using spores
Fungi as decomposers

Fungi play an essential role in maintaining equilibrium in
nearly every ecosystem, where they recycle nutrients by
breaking down the bodies and wastes of other organisms
Lichens
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Fungus + Algae
Fungus gets food from the algae
The algae get water and minerals from fungus
Mycorrhizae
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Fungi + Plants
Roots of plants are woven into a
partnership with an even larger
web of fungal mycelia
Benefits

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Hyphae of fungi aid plants in absorbing
water and minerals
Fungi release nutrients enzymes that free
nutrients in the soil
Plant provides the fungi with the products of
photosynthesis.
Cladograms
•
Show shared derived
characteristics
•
Lungfish,
mammals, birds,
and lizards evolved
with vertebrate and
lungs
•
•
They share these two
derived characteristics
All living organisms share the same
molecule of DNA (or genetic information)
Kingdom Plantae
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Cell Type: Eukaryotic
Cell wall contains Cellulose
Body Type: Multicellular
Nutrition: Autotrophic
Examples: corn, ferns, roses, pine tree
Kingdom Animalia
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Cell Type: Eukaryotic
Nutrition: Heterotrophic
Body Type: Multicellular
Examples: insects, humans, coral, starfish
1.
2.
3.
4.
5.

Sunlight
Water
Minerals
Gas Exchange
Transport of water and nutrients
throughout the plant body
Remember Photosynthesis:

6H2O + 6CO2 → C6H12O6 + 6O2
(water + carbon dioxide + sunlight  glucose + oxygen)
 Plants
most likely evolved from an organism
like the freshwater multicelluar green algae
living today.
 Plants had to overcome “challenges” as they
moved from water to land:
Adapt to be able to acquire water
 Adapt features to transport water
 Be able to conserve water more efficiently

Vascular vs. Nonvascular

VASCULAR PLANTS – Contain tube-like cells for
transport
•

Can grow large and farther away from water source
NONVASCULAR PLANTS – Don’t contain tube-like cells
for transport
•
•
Water and nutrients travel by diffusion
and osmosis.
Small and grows close to water source
4 main plant groups:
Nonvascular
 1. Bryophytes (Mosses and their relatives)
Vascular (Tracheophytes)
 2. Seedless Vascular (Ferns and their relatives)
 3. Seeded Vascular
a) Gymnosperms (cone-bearing plants)
b) Angiosperms (flowering plants)
Bryophytes vs.
ferns (seedless vascular)
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Same for both:
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Eukaryotic
Multicellular
Need water for
reproduction
Moist, shady habitats
Reproduce with
spores
Photosynthetic
Bryophytes
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Small size
Non-vascular (don’t have water conducting tissue)
No true roots, stems, and leaves
Mosses
Examples of Nonvascular Plants:
 Includes: Mosses
 Liverworts

Hornworts
Ferns
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Vascular
True roots, stems, and leaves
Ferns
Vascular Plants
FERNS
GYMNOSPERMS
(CONE BEARING PLANTS)
ANGIOSPERMS
(FLOWERING
PLANTS)
Tissue types :
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Vascular Tissue is gathered into veins made of:
1. Xylem - Transports water and minerals throughout
the plant
(The rings of a tree are the remains of old xylem tissue)
2. Phloem - Transport sugars produced by photosynthesis
to the roots of the plant.
-dripping sap(sugars) coming from a tree is
usually from the phloem
REMEMBER: Sap (sugar) Phloes out of the tree
Seed plants - gymnosperms
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Bear their seeds directly on the surface
of cones.
Vascular plants
Gymnosperm means “naked seed”
Includes conifers such as pines and spruces
Angiosperms – flowering plants
#10 Difference between gymnosperms and
angiosperms?


Gymnosperms reproduce with cones.
Angiosperms reproduce with fruits and flowers.
PLANT RESPONSES

The way in which plants grow in response to stimuli in their
environment are called tropisms. Three main tropisms are:
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Geotropism or Gravitropism- response to gravity
Phototropism- response to light
Thigmotropism- response to touch
Phototropism
Geotropism
Thigmotropism
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The ovary develops into the fruit
Can be dry (nuts and grains) or Fleshy (peaches,
tomatoes, squash)
Fruits protect the seeds and aid in dispersal
Reproduction of angiosperms
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STAMEN
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MALE PART = ANTHER
THAT PRODUCES POLLEN
AND THE FILAMENT
(STALK THAT SUPPORTS
THE ANTHER)
CARPEL

FEMALE PART = STICKY
STIGMA,TUBELIKE STYLE,
AND OVARY WHICH
CONTAINS OVULES WITH
EGGS INSIDE
POLLINATION
Pollination – Transfer of pollen from the
stamen to the pistil.
Methods of Pollination:
1. Wind
2. Animals (most are
pollinated by animals)
Pollination Adaptations That Attract Animals:
1. Nectar
2. Petal Color
3. Scent

Plants have 3 main organs: roots, stems, & leaves
 Roots
– absorbs water and dissolved
nutrients, anchors the plant, protect the
plant from bad soil, and transports water to
rest of the plant
 Stems – support system for the plant body,
transport system for water and nutrients
 Leaves – plants main photosynthetic system
Functions:
 most photosynthesis takes place here
 absorb sunlight
 contain pores (stomata) for gas exchange
Guard cells:
• cells that open and
close the stoma
Stomata: openings in
underside of leaf’s
surface; when open:
• GAS EXCHANGE:
Allows CO2 in & O2
out of leaf
• TRANSPIRATION:
Allows excess H2O
out of leaf
1.
2.
3.
Roots-Underground
structure that help
prevent soil erosion
Cuticle- Waxy covering
on leaves that prevents
water loss
Guard Cells- Cells that
surround leaf openings
that control the amount
of transpiration by closing
during hot or dry times
4. Mesophyll- The
part of leaf where
photosynthesis
occurs
5. Xylem- Vascular
tissue that
transports water
through the roots,
stems and leaves
6.
7.
Root Hairs-Tiny
projections that increase
the surface area for the
absorption of water and
nutrients from the soil
Stomata- Opening found
in leaves that allows for
gas exchange and
transpiration with the
environment
8. Phloem- Type of
transport tissue
that transports
food through the
leaves, stems and
roots
9. TranspirationProcess by which
water evaporates
from the leaves
of plants
 Photosynthesis:
o 6H2O
+ 6CO2 → C6H12O6 + 6O2
(water + carbon dioxide + sunlight  glucose +
oxygen)
REACTANTS
o
PRODUCTS
Carried out by chloroplasts in the leaves
• Plants also carry out cellular respiration:
– Glucose + oxygen  carbon dioxide + water + energy
(ATP)
REACTANTS
PRODUCTS
o Carried out by mitochondria in the cells
What is an Animal?
Characteristics of All Animals
1. Animals are Multicellular
2. Animals are Eukaryotic
3. Animals are Heterotrophs
4. No cell wall
Evolutionary/Developmental
Milestones in Animals
1. Cell specialization and levels of
organization. Cells Tissues organs
organ systems organism
2. Development of body symmetry and
segmentation
3. Development of an internal body cavity
and tissue layers
Homeostasis
All of the organ systems work
together to keep the body in a
state of HOMEOSTASIS.
Homeostasis is the process by
which an organism maintains a
relatively stable internal
environment.
Body Symmetry
Asymmetry
no front or back;
no right or left
side
Radial Symmetry
body parts repeat
around the center
Bilateral Symmetry
– one plane of
symmetry; definite
right and left sides
Trends in Animal Evolution

Animals with bilateral
symmetry usually exhibit
cephalization

concentration of nerve cells
and sense organs at the front
end of the body
Cell Specialization
Cells throughout a multicellular organism can
develop in different ways to perform different tasks.
ANIMAL BODY SYSTEMS
Body systems are all interrelated and work together to perform
their functions in animals. Body systems can be organized and
studies by these functions:
 REGULATION: Excretory & Nervous Systems
 NUTRIENT ABSORPTION: Respiration,
Digestion, & Circulatory Systems
 DEFENSE: Immune, Integumentary, Lymphatic,
Skeletal, & Muscular Systems
 REPRODUCTION: Reproductive & Endocrine
Systems
Animal Systems- Defense!
Defense!
 Integumentary System
 Acts as a protective barrier; helps
prevent excess water loss; helps
regulate body temperature
(sweating and shivering).
 Skeletal System
 The skeletal system produces
immune cells (immune system) to
protect against disease causing
bacteria and viruses.
 These immune cells(white blood
cells) are then carried by the
circulatory system for the immune
response when needed.
 The main organs of the skeletal
system are the bones. Bones
work with muscles to move,
protect, and support sensitive
internal organs.
Skeletal Body System
Interactions:
 Circulatory System: bones help produce new blood
cells in addition to storing minerals transported by the
circulatory system.
 Muscular System: bones and muscles work in opposing
pairs to perform body movement. Muscles and bones
support, protect, and maintain posture for the human
body.
 Nervous System: bones protect many vital organs of
the nervous system – Skull (brain), Vertebrae (spinal
cord).
Animal Systems- Defense!
Defense!
 Muscular System
 main organs of the muscular system are the muscles. There are 3
types of muscles tissue made up of individual muscle cells, called
fibers
 Bones and muscles work in opposing pairs to perform body
movement. Muscles and bones support, protect, and
maintain posture for the human body
 coordinates with the nervous system to help animals
respond to their environment.
 Immune/ Lymphatic System
 Your skin is your first line of defense. The skin works to
keep pathogens out, then the immune system will attack
them if they get in
Interaction with Other Body Systems
Skin is the first line of
defense in the immune
system response.
The circulatory system and
skin regulate body
temperature.
Skin and the excretory
system excrete water, urea,
salts, and other wastes
through sweat.
Receptors of the nervous
system are located in skin.
Interaction with other systems
for Regulation
 Bones of the skeletal system protect the
spinal cord and brain.
 The brain controls heart rate, blood pressure,
and breathing via the circulatory and
respiratory systems.
 Glands in the brain control the release of
hormones of the endocrine and reproductive
systems.
 The brain controls muscles both in digestion
and movement.
Animal SystemsNutrient Absorption
 Digestive
 Breaks down food into nutrients like glucose
 converts food into simpler molecules that can be used by the cells of
the body; absorbs food and eliminates waste
 Circulatory
1. Transports O2 & nutrients (sugars, amino acids, hormones) to the cells
2. Carries wastes away from cells
 Respiratory
 Takes in oxygen
 Provides O2 to the blood for cellular respiration in the cells and removes
CO2 from the body
 Exchange of gases occurs through the walls of the lungs
Interactions Among Systems to Achieve
Nutrient Absorption
Nutrients are obtained from food
that the digestive system has
broken down. The respiratory
system obtains oxygen from the
atmosphere. These nutrients are
transported by the circulatory
system to cell of the body for
absorption.
Comparing Reproductive Systems
Asexual
Sexual
Involves one parent. As a result, the
offspring tend to have the same
genotype and phenotype as the parent.
involves the fusion of two gametes.
Sperm and eggs are sometimes
produced by the same individual and
sometimes produced by different
individuals.
Ex: Flatworms can divide into 2 halves; each half
grows into a separate organism. Cnidarians
undergo budding where a new individual grows
from and then breaks off of the parent individual.
Ex: Vertebrates
Genetically identical
Genetic variation
Animal Systems-Reproduction
 Reproductive
 combines genetic information from both parents (in most
animals) to produce new life forms.
 This system produces sex cells (gametes), delivers them,
and protects a developing fetus until birth.
 Endocrine
 regulates long-term changes in the body such as growth
and development
 It is made up of glands that release their products into the
bloodstream
The Endocrine system working with other
body systems…
 Nervous System: Hormones provide feedback to the brain
to affect neural processing.
 Reproductive System: hormone production for sexual
development to make offspring
 Muscular and Skeletal System: endocrine system
controls the growth of both bone and muscles
 Immune System: the development is controlled by the
endocrine system
 Digestive System: The endocrine system controls the
rate of metabolism
Animal Systems-Regulation
 Nervous
 maintains homeostasis by controlling and regulating all
other parts of the body.
 Excretory
 helps regulate the concentration of water and other
components of body fluids.
Cellular respiration
 What is the equation for Cellular Respiration?
 Glucose + oxygen  carbon dioxide + water + energy/ATP
 What system provides the glucose for this process?
 digestive
 What system provides the oxygen for this process?
 respiratory
 Where in the cell does this process occur?
 mitochondria
Components of blood and their
function
 White blood cells
fight off
pathogens/destroy
bacteria and pathogens
 Platelets
help clot blood
 Red blood cells
contain hemoglobin and
carry oxygen
 Plasma
liquid part of blood
Gametes
 The female gametes are called ova/egg and are
released from the ovaries.
 The male gametes are called sperm and are produced in
the testes
3 types of Muscles and examples
 Skeletal
 Skeletal is attached to bones for
movement
 Cardiac
 cardiac muscle is only found in
the heart
 Smooth Muscle tissue
 smooth is found lining the blood
vessels, stomach, small
intestine and diaphragm
 The picture to the left is
represents the cells of
the nervous system
which are what????
 Neuron!
What Is Ecology?
Ecology- is the study of the interactions among
organisms and between the organisms and the
environments in which they live.
(eco means “house”)

.

Biotic factors – all living things


Ex. Types of plants, animals, bacteria, fungi, etc.
Abiotic factors – all non-living things

Ex. Climate, temperature, amount of rainfall,
humidity, light, wind, soil type, nutrients available,
etc.
Levels of Ecological Organization
(most specific) Species → Population → Community →
Ecosystem → Biome → Biosphere (most broad)
Important Ecology Terms
1. Species - Group of organisms so
similar to one another that they can
breed and produce fertile offspring.
2. Population - Groups of individuals that
belong to the same species and live in
the same area.




Communities - Assemblages of different populations that
live together in a defined area.
Ecosystems – Collection of all the organisms that live in a
particular place, together with their nonliving, or physical,
environment.
Biome -- Group of ecosystems that have the same climate
and similar dominant communities.
Biosphere -- Contains the combined portions of the
planet in which all of life exists, including land, water, and
air, or atmosphere
Sunlight  Producers  Consumers  Decomposers
Producers: autotrophic organisms that are able to make
own food from a inorganic substances.
Ex. Plants, algae (phytoplankton-microscopic marine plant
life)
Consumers:

Sunlight  Producers  Consumers  Decomposers
Consumers: heterotrophic organisms that get energy
by eating producers and other consumers. (ex. Deer,
hawk, bear)
Herbivores: eat producers
ex. Deer, grasshopper, cow
Carnivores: eat other consumers
ex. Frog, wolf, hawk
Omnivores: eat producers and consumers
ex. Grizzly bear, humans
Level of Consumers:
Primary consumer Secondary consumer3rd, 4th …level consumer
Herbivore
Carnivore
_______________
__________________
Omnivore & decomposers
_______________________ can be 1st,2nd or higher level consumer
Sunlight  Producers  Consumers  Decomposers
Decomposers:

Obtain energy from eating the remains of other
organisms (recyclers) Ex.
•Two Principle Decomposers:
Bacteria and Fungi
Worms
Bacteria
Fungi
Termites
Earthworms and termites (detritivores) also aid in the breakdown of
organic matter, which replenishes nutrients to the soil.
Omnivores

Eats both plants and
animals

Ex-Humans
What Do Food Chains and Food
Webs Demonstrate?


Each step in a food chain or web is called a trophic
level, or a feeding relationship between organisms.
Both food chains and food webs show the flow of
energy in an ecosystem.
Energy flows from
the leaf to the
mouse
Energy flows
from the snake
to the hawk
Food Chains

Food Chain: one way flow of
energy illustrates only one feed
relationship
Quaternary
consumers
5th

Arrows show the flow of energy
and matter
4
Tertiary consumers
th
Secondary
consumers
3rd
Primary consumers
2nd
Producers
1st
Food Webs

Food Web: links all the food
chains in an ecosystem together.

Any change in a population or
trophic level of a food chain can
seriously alter all other organisms of
the food web!

A healthy ecosystem has a large
diversity of life because of the
availability of alternative food
sources.
When studying the
overall health of an
ecosystem, we study
food webs.
Ecological Pyramids


Ecological Pyramiddiagram that shows the
relative amounts of energy
or matter contained within
each trophic level in a food
chain or food web.
Only 10% of the energy
available is passed on to
the next level…90% is lost
as heat.
Parasitism

One organism benefits, and the other is harmed
(host).
Ticks feed on the blood of the host in which they live. The
closer together organisms live, the easier these parasites can
spread through the population.
Mutualism

Both organisms benefit from the relationship.
This bird will eat the insects found
on the zebras’ body. The bird is
high above the ground and has
food, the zebra is removed of
pests.
Bees receive food, while the
flower’s pollen is spread for
reproduction.
Commensalism

One organism benefits, and the other is neither
helped nor harmed.
Barnacles live and grow on the bodies of various ocean organisms,
however, they do not cause any harm to them. They do not aid them
in any way, though.
The Carbon Cycle
In photosynthesis, producers
remove CO2 gas from the
atmosphere to make
organic molecules (sugars).
Cellular respiration Animals burn
the food they eat releasing
CO2 gas as a waste product.
Combustion: Burning Fossil
Fuels. When they are
burned, CO2 gas is returned
to the atmosphere and
increases the amount of
CO2 gas in the air.
The Nitrogen Cycle
Ecological Succession
• Ecosystems are constantly changing in
response to natural and human disturbances.
• As an ecosystem changes, older inhabitants
gradually die out and new organisms move in,
causing further changes in the community.
– Ecological Succession – Series of predictable
changes that occurs in a community over time
Primary Succession
• Soil starts to form as lichens and the
forces of weather and erosion help break
down rocks into smaller pieces
• When lichens die, they decompose,
adding small amounts of organic matter to
the rock to make soil
Secondary Succession
• Begins in a place that already has soil and
was once the home of living organisms
• A disturbance of some kind changes an
existing community
• Occurs faster and has different pioneer
species than primary succession
• Example: after forest fires