Transcript FINAL SPRING REVIEW

FINAL SPRING MULTIPLE
CHOICE REVIEW
Cane Toad Studies



In Australia the cane toad is a non-native species that
reproduces with no predator and is wreaking havoc on the local
ecosystem.
To combat these amphibians, the indigenous people want to test
a new chemical that is sprayed on the toad eggs prior to
hatching. The spray is shown to only work (prevents maturity)
on the following genotypes:
LL, Ll (large legs)
This spray is not effective on
the ll variety (small legs).
Cane Toad Studies
• What should the indigenous
people’s investigative question
be?
– Does the spray prevent
maturity of toad eggs therefore
decreasing population size?

What should the indigenous people’s hypothesis be?
If spray is used on cane toad eggs then maturity
will be prevented therefore decreasing population
size.
 All hypotheses are in the “If, then” format.

Cane Toad Studies

How can the indigenous people test their hypothesis?


They can apply spray to some toad eggs measure the rate
of maturity after a month.
How will they know that spray decreased maturity of
toad eggs?
 They can measure the population size of cane toads a
month without spray and compare it to the population
size with spray.
What are experimental variables?

In this experiment what is the:

Independent variable?

Applying the spray to the toad eggs.


Remember, the independent variable is
what the scientist manipulates!
Dependent variable?

The maturity of the eggs (as measured
by the population size) .

The dependent variable is what the
scientist measures!


Control?
 The measurement of egg maturity WITHOUT spray.
 The control is something you can COMPARE the
results to.
Constants?
 The variables that are kept the same in both the control
and experimental set up.
 Constants are kept the same so that you are only
testing one variable at a time.
 Examples: measure egg maturity at the same time of
year, apply the spray in the same manner for all eggs,
measure data for the same length of time.
How do you interpret a data table?

Recorded results in this table.

What should their conclusion be?

Their conclusion should be that spray works!
Spray Results
WITHOUT
SPRAY
Week 1
Week 2
Week 3
Week 4
# mature eggs
100
105
111
109
WITH SPRAY
Week 1
Week 2
Week 3
Week 4
# mature eggs
50
35
29
32
# of mature eggs
How do you graph information?
Weeks  1-4


The independent variable is on the X-axis
The dependent variable is on the Y-axis

You can compare the control AND the variables by doing a multi-line
graph!

Cane toad studies

If the spray works then the
population of cane toads will
decrease, but since the spray
only affects genotype LL and
Ll the population will increase
again due to reproduction of
the ll cane toads.
The genotypic variation
(alleles within the population)
of cane toad will …


Increase?
Decrease?
How do you confirm experimental data?

To confirm the results of the experiment, they should…


Repeat the experiment again
Have more test subjects
How do you get from DNA to chromosomes
to genes?


DNA is condensed into
chromosomes
Chromosomes contain
genes that will become
traits
Who identified the structure and
function of DNA?

Fredrick Griffith was
experimenting with two forms of
bacteria (S and R form).



After heat-killing S bacteria, and
mixing it with R bacteria, he found
that the R bacteria had transformed
into S bacteria.
He called this the “transforming
principle”.
Avery, Hershey, and Chase
confirmed that the “transforming
principle” was DNA.
Who identified the structure and
function of DNA?


Maurice Wilkins & Rosalind
Franklin
 Took x-ray photos of DNA
(crystallography / diffraction) to
determine double helix structure
of DNA
Erwin Chargaff
 Discovered base pairing rules
 A pairs with T
 C pairs with G
Who identified the structure and
function of DNA?
 James Watson
and Francis Crick
 Interpreted photos and data to
generate a 3 dimensional structure of
DNA that was a twisted double helix
 Circa 1953
Who identified the structure and
function of DNA?
 Robert
Hooke
 First described what a cell looked
like! (This was WAY back in the
1600’s)
DNA Replication

To replicate DNA …



Helicase cuts the hydrogen bonds
DNA polymerase adds complimentary nucleotides to the
two open strands generating two new double helixes.
http://www.youtube.com/watch?v=hfZ8o9D1tus
DNA Replication

Here is a string of DNA:




DNA =
DNA=
C
G
C T A C
G A T G
G G G A T T C
C C C T A A G
DNA’s double strand is held together by weak hydrogen
bonds
Each nucleotide (containing a nitrogen base, sugar and
phosphate) is held together between the sugar and
phosphate by strong covalent bonds
RNA!

RNA is a nucleic acid with



Ribose sugar
The nitrogen base Uracil (lacking
Thymine)
A single strand
How do you TRANSCRIBE DNA?

Here is a string of DNA:



DNA = C
mRNA = G
C T A
G A U
C
G
G
C
G
C
G A T T C
C U A A G
To TRANSCRIBE the DNA, you have to make it into
mRNA.



Adenine pairs with Uracil
Guanine pairs with Cytosine
Thymine pairs with Adenine

This process takes place in the NUCLEUS!

The DNA strand is too large to leave the nucleus, but the mRNA strand
can.
How do you TRANSLATE DNA?

Now you have your new mRNA strand!

G G A U G C C C U A A G


It is smaller than the DNA strand, and can leave the nucleus for the
cytoplasm.
Once in the cytoplasm, it hooks up with a ribosome, that
“reads” the mRNA strand three nucleotides at a time (a
codon) with the help of tRNA.

This process is TRANSLATION.
How do you TRANSLATE DNA?

Every three nucleotides on the mRNA
is a codon.

Every codon has an anti-codon that carries
an amino acid!


As tRNA brings its anti-codons (and amino
acids) to the mRNA strand, it builds
PROTEINS!
We know which amino acids go with each
codons because there is a universal code.

Our mRNA strand: G G A U G C C C U A A G




Is coding for: GGA = Glycine
UGC= Cysteine
CCU= Proline
AAG= Lysine
How do you TRANSLATE DNA?
peptide bond
ribosome
aa1
aa3
aa2
3-tRNA
1-tRNA
Anti-codon
hydrogen
bonds
U A C
A U G
codon
2-tRNA
G A A
G A U
C U A C U U C G A
mRNA
Where does transcription and translation take
place?

REMEMBER:

TRANSCRIPTION is in the NUCLEUS!

TRANSLATION is in the CYTOPLASM!

http://www.youtube.com/watch?v=983lhh20rGY
The Cell Cycle

G1

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
S
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Cell grows
During G0, the cell does its job
and either never or rarely
divides
Cell replicates its DNA
G2

Cell grows again

ALL of these are INTERPHASE!
What makes the cell move from phase
to phase in the cell cycle?

There are checkpoints within the cell cycle that are
controlled by enzymes and hormones.


If the cell is not ready to move on the enzymes will prevent
then next phase from happening.
If the cell IS ready then other enzymes allow the cell to
proceed.
What are the purposes and processes of
Mitosis?



Division of the nucleus
 Used for repair and growth
 Only happens in EUKARYOTIC
cells
Includes 4 steps
 Prophase
 Metaphase
 Anaphase
 Telophase
Results in:
 TWO genetically IDENTICAL
DIPLOID daughter cells
What are the purposes and processes of
Meiosis and cell cycle?


Produces gametes (egg or sperm)
Includes steps
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Results in:
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
Interphase
PMAT I + cytokinesis
PMAT 2 + cytokinesis
4 genetically DIFFERENT HAPLOID daughter
cells.
SPECIAL EFFECTS
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Homologous pairs come together: PI
Crossing over occurs: PI
Homologous pairs split: AI
Sister chromatids split: AII
What is crossing-over?

Sister chromatids in
a tetrad cross over
each other

Pieces of
chromosomes or genes
are exchanged


Produces genetic
recombination in the
offspring
These are called
homologous
chromosomes
What is the difference between mitosis and
meiosis?
What is the difference between mitosis
and meiosis?
Mitosis
Meiosis
# of divisions
1
2
# of daughter cells
2
4
Genetically Identical
Yes
No
Chromosome #
46 (diploid)
23 (haploid)
Where
Somatic (body) cells
Gamete cells
When
Throughout life
After puberty
Role
Growth and repair
Sexual reproduction
What does haploid and diploid mean?

Diploid


Di = two
Ploid = chromosomes



Having two chromosomes for each trait
In humans 46 (normal body cells)
Haploid


Hap = half or one
Ploid = chromosomes


Having one chromosome for each trait
In humans 23 (gamete; egg or sperm)
What occurs on the cellular level during
fertilization?
Father
contributes 23
chromosomes
Mother
contributes 23
chromosomes
Fertillization
results in a
recombined 46
chromosomes
Who is Gregor Mendel?


Mendel studied genetics
through the use of math,
probability and pea plants.
He found that variation
occurs through the
inheritance of individual
alleles from each parent


Dominant alleles mask
recessive alleles (TT- tall, Tttall)
Recessive alleles are only
expressed when both present
(tt- short)
Gregor Mendel


Titled the Father of Genetics due to his numerous studies and
detailed notes on the inheritance patterns in Pea Plants
Mendel observed the physical characteristics (phenotype) of the
offspring to generate his three laws about the genotypes (alleles)
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Law of Dominance
Law of Segregation (alleles separate during meiosis)
Law of Independent Assortment (all traits are inherited independently)
What is the genotypic and phenotypic ratio?

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A loving couple wants to have children.
They are both heterozygous for brown
eyes. They want a blue-eyed child. What
are their chances?
Genotype
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Gene combination for a trait (Bb, BB, bb)
Phenotype

The physical feature resulting from the trait.
(brown eyes or blue eyes)
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
Mom has the genotype Bb.
Dad has the genotype Bb.
What is the genotypic and phenotypic ratio?
Mom has genotype: Bb
Dad has genotype: Bb


B
b
B
BB
Bb
b
Bb
bb
The genotypic ratio is 1:2:1 or BB : Bb,Bb : bb
The phenotypic ratio is 3:1 or brown, brown, brown : blue
Dihybrid cross- used to determine
probability of cross between two traits

http://www.biology.arizona.edu/mendelian_genetics/proble
m_sets/dihybrid_cross/03t.html
Testcross- cross between an organism with
homozygous recessive genotype and a
second organism with an unknown
genotype.

The offspring results will
show whether the
organism with unknown
genotype is
heterozygous or
homozygous dominant.
What is the difference between incomplete
and codominance?
Parents:
MOM
DAD
Incomplete Dominance


The offspring will have a
phenotype somewhat in between
the phenotypes of the two
parents.
Co-Dominance

Both alleles are expressed in the
offspring.
Patterns of Inheritance
INHERITANCE PATTERN and
definition
EXAMPLE
Multiple alleles- many alleles
affect one trait
ABO blood system or Eye color
Epistatic Genes

Epi = upper

These are genes that
will “mask” other
genes.
This little white
chimpanzee has genes for
dark hair/fur, brown eyes,
and peach/tan colored
skin, BUT he also has the
gene for albanism. As an
epistatic gene, it stops all
melanin (responsible for
color in the hair, eyes, and
skin) from being produced.
It “masks” the expression
of all the other genes.
Polygenic


Poly = many
Genic = genes

These are traits
controlled by more
than one gene.
Height is a polygenic trait. There may be as
many as 20 genes directly involved!
Pleiotropy
Alleles at one locus affect many
traits
Sickle cell anemia has many health
effects like clotting blood, heart
problems, etc
Karyotype- a picture of chromosomes
Karyotyping and disorder discovery
Down Syndrome
(caused
by non-disjunction of the
chromosomes during division)
Trisomy- When there are 3
chromosomes
Karyotyping and disorder discovery
Klinefelter
syndrome
Thomas Hunt Morgan

Worked with Fruit Flies and
discovered LINKAGE
 Locus- region on a
chromosome where alleles
for genes are located
 Linked genes- alleles/genes
that rarely separate during
meiosis
 Genes that are closer
together tend to be linked
Sex-Linked

Sex-Linked traits (traits on the X and Y chromosome)
tend to show up more often in males because they only
have one copy and do not have a second allele to mask it.
What conditions promote the inheritance of
genetic traits?

Fitness

Fitness is a measure of the
ability to survive and
produce more offspring
relative to other members
of the population in a given
environment.

After the climate change,
jaguars that had larger teeth
and jaws had a higher fitness
than other jaguars in the
populations.
Jaguar Fossil
Modern Jaguar Skull
What evidence supports evolution?

Fossils


Embryology


Similar features in the embryos of
different organisms suggests evolution
from a distant common ancestor.
Comparative Anatomy


Fossils show changes in organisms
through time.
Pig
Dolphin
Homologous, analogous, and vestigial
structures give a peek in to the
history of changes that have occurred
in organisms.
DNA

DNA studies show entire gene
sequences in common between
organisms.
Human
Use the following chart to draw a cladogram.
Label the different parts of your cladogram
and then explain the relatedness of the
organisms.
Character used in analysis
4 legs
Fur
Tail
bipedal
Fish
-
-
+
-
Reptiles
+
-
+
-
Monkeys
+
+
+
-
Apes
+
+
-
-
Man
+
+
-
+
Fish
Reptiles
Monkeys
Apes
Human
Bipedal
Lack of tail
Fur
4 legs
Cladogram- a branching diagram showing
the evolutionary relationship between
organisms

The more derived characters two organisms have in common, the
more related they are.
Clades
Derived characters
What is comparative anatomy?

Homologous structures


Analogous structures


Features that have SIMILAR
STRUCTURES but
DIFFERENT FUNCTIONS
Features that have the
SAME FUNCTION but
DIFFERENT STRUCTURES
Vestigial structures

Remnants of structures that
ONCE HAD A FUNCTION
but NO LONGER DO
What are patterns in the fossil record?

Punctuated Equilibrium


Bursts of evolutionary
activity are followed by
long periods of stability.
Adaptive Radiation


Frilled Sharks
have been
around for
millions of years.
The diversification of one
ancestral species into many
descendent species.
Anolis lizards have
undergone adaptive
radiation on the
Caribbean Islands.
Extinction

Extinctions often occur
when a species as a whole
is unable to adapt to a
change in its environment.
The last Golden Toad
was seen in 1989. It is
thought that a
combination of global
warming and pollution
lead to its extinction.
How do genetics support the idea of
evolution?

The basic definition of
evolution is a change in
the gene pool of a
population of organisms
over time.



All of evolution is based on
genetic change.
Genetic similarities between
two organisms point to a
common ancestor.
By following mutation rates,
scientists can guestimate
how far back two species
diverged from a common
ancestor.
Bonobo
Chimpanzee
By looking at the accumulated mutations in the DNA of
Bonobos and Chimpanzees, scientists have determined
that these two species separated from a common ancestor
less than one million years ago.
What is natural selection?

Natural selection is a
mechanism by which
individuals that have
inherited beneficial
adaptations produce more
offspring on average than
do other individuals.

In nature, the environment
is the selective agent.

Therefore, characteristics are
selected only if they give
advantages to individuals in
the environment.
What are the causes and effects of natural
selection?

There are four main principles to the
theory of natural selection:

Variation


Overpopulation


Organisms have more offspring than can
survive.
Adaptation


Heritable differences, or variations, exist in
every population
Sometimes, a certain variation allows an
individual to survive better than other
individuals it competes against in its
environment.
Descent with Modification

More individuals will have the variation in
every following generation.
What are the causes and effects of
natural selection?

Descent With
Modification

Over time, natural selection
will result in species with
adaptations that are well
suited for survival and
reproduction in an
environment.

More individuals will have the
trait in every following
generation, as long as the
environmental conditions
continue to remain beneficial
for that trait.
How do new species emerge?

Isolating Mechanisms


Reproductive Isolation


Occurs when two populations are capable of
interbreeding but have differences in courtship rituals
or other reproductive strategies.
Geographic Isolation


Reproductive isolation occurs when members of
different populations can no longer successfully mate
with one another.
Behavioral Isolation


To make new species, the gene pools of the
populations must become separated.
Two populations are separated by a geographic
barriers such as rivers, mountains, or bodies of water.
Temporal Isolation

Two or more species reproduce at different times.
What are the characteristics of species?

A species is a group of
organisms that INTERBREED
with one another and produce
FERTILE/VIABLE OFFSPRING.
Chinstrap Penguin
Emperor Penguin
Macaroni Penguin
What is a species?

All of these lizards live near
each other and eat the same
types of food. Populations A
and B will mate together
where their populations
come into contact with each
other (the overlapping circle)
and produce fertile offspring.

How many species are
represented by this graph?
 6!
 Because A and B can
breed and produce
fertile offspring, they
are considered to be a
single species.
A
C
D
C
B
E
F
G
What are allele frequencies?

Genetic variation is stored in a population’s gene pool—the
combined alleles of all the individuals in a population.


Different combinations of alleles in a gene pool can be formed when
organisms mate and have offspring.
Each allele exists at a certain rate, or frequency.

An allele frequency is a measure of how common a certain allele is in the
population.
How do allele frequencies change?

Mutation


Recombination


A mutation is a random
change in the DNA of a
gene.
Most recombination
occurs during meiosis—
through crossing over.
Hybridization

The crossing of two
different species that
share common genes.
How do you graph allele frequencies?

Normal Distribution


Directional Selection


When natural selection favors
phenotypes at one extreme of a
trait’s range.
Normal
Directional
Stabilizing Selection


Most traits will fall under normal
distribution (bell curve)
When natural selection favors
phenotypes in the middle of a trait’s
range.
Disruptive Selection

When natural selection favors both
extreme phenotypes, while
individuals with intermediate
phenotypes are selected against.
Stabilizing
Disruptive
How do humans influence allele
frequency?

Genetic Drift


Bottleneck Effect


Genetic drift causes the LOSS of
genetic diversity in a population.
The bottleneck effect happens
when an event greatly reduces the
size of the population.
Founder Effect

The founder effect happens after
a small number of individuals
colonize a new area.
How does the environment influence
allele frequency?

Industrial Melanism

Refers to the genetic darkening of species in response to pollutants.

Originally, the vast majority of peppered moths had light coloration, which effectively
camouflaged them against the light-colored trees and lichens upon which they rested.

Widespread pollution during the Industrial Revolution in England, many of the lichens
died out, and the trees which peppered moths rested on became blackened by soot,
causing most of the light-colored moths to die off due to predation.
 At the same time, the dark-colored moths flourished because of their ability to
hide on the darkened trees.

Since then, with improved environmental standards, light-colored peppered moths
have again become common.
How does the environment influence
allele frequency?

Peppered coloration (PP and Pp)
is dominant to black coloration
(pp) in moths.

Which moth phenotype would have an
increased fitness after the industrial
revolution?
 Soot blackening the trees caused most
of the light-colored moths to die off
due to predation.
 At the same time, the dark-colored
moths flourished because of their
ability to hide on the darkened
trees.
 Fitness is the ability to outbreed
your competitors!
P
p
P
PP
Pp
p
Pp
pp
How does immigration affect allele
frequency?

Gene Flow


The movement of alleles from one
population to another is called gene flow.
For many animals, gene flow occurs when
individuals move between populations.
 For example: Certain birds leave their
nesting areas once they are able to fly.


These birds most likely join new
populations.
The alleles that these birds have then
become a part of another population’s
gene pool.
 Gene flow increases the genetic
variation of the receiving population.
Opening science to new ideas

Carl Linnaeus was a Swedish botanist, physician, and
zoologist, who generated the modern biological naming
scheme of binomial nomenclature.

Latin based system that uses the genus and species
classifications to name organisms.


Ex: Humans are known as Homo sapiens
Ex: Jaguars are known as Panthera onca
Who is Charles Darwin?

Darwin is a naturalist who studied
variations in organisms, geology and
fossils.



He wrote a book called On the Origin of
Species that explained how natural
selection occurs.
He thought that traits were blended and
was unaware of Mendel’s studies on how
heritable characteristics are inherited
distinctly from each parent which led to
variation in offspring.
Darwin’s idea of natural selection helped to
explain that traits will be passed to future
generations and increase variation in
members of a population.
What is the difference between biotic and
abiotic factors?

Biotic


Factors that are living
things, such as plants,
animals, fungi, and bacteria.
Abiotic

Factors that are non-living
things such as moisture,
temperature, wind, sunlight,
and soil. The balance of
these factors determines
which living things can
survive in a particular
environment.
What influences do biotic and abiotic factors
have on populations?

Density-Dependent Limiting Factors

A limiting factor that depends on
population size.

Usually includes biotic factors





Competition
Predation
Parasitism
Disease
Density-Independent Limiting
Factors

Affect all populations in similar ways,
regardless of the population size.

Usually includes abiotic factors


Fire
Drought
What are some differences and similarities
between heterotrophs and autotrophs?

Autotrophs
Also known as producers
 Organisms that get their
energy from non-living
resources, meaning—they
make their own food.


Heterotrophs

Also known as consumers

Organisms that get their
energy by eating other living
or once-living resources, such
as plants and animals.
How do you interpret a food chain?

A food chain is a
sequence that links
species by their feeding
relationships.

This model chain only
shows the connection
between ONE producer
and a SINGLE chain of
consumers within an
ecosystem.

Energy flows from
PRODUCER TO
CONSUMER
Compare a food chain and an energy
pyramid.

An energy pyramid is a diagram that compares the energy used by
producers, primary consumers, and other trophic levels.


As energy moves up the food chain—IT DECREASES
Those organisms at the top of the food chain, have the lease amount of
energy.
Food Webs

Show complex food relationships in ecosystems.

Arrows show the movement of energy through the food web.

Pick out a single food chain in this web.

Fungi to squirrel to hawk!
How do biomass levels change through food
webs and energy pyramids?
 Biomass


pyramid
Diagram that compares the
biomass of different trophic
levels within an ecosystem.
It provides a picture of the
mass of producers needed
to support primary
consumers, the mass of
primary consumers needed
to support secondary
consumers, and so on.

As you go UP the food chain
biomass DECREASES
5 Hawks
5,000 snakes
500,000 bunnies
5,000,0000 blades
of grass
How does immigration and emmigration affect
population size?

Immigration



The movement of
individuals into an area.
Causes population
growth.
Emigration


The movement of
individuals out of an area.
Causes population
decline.
What is carrying capacity?

Carrying Capacity (K)


The environment can only
support so many
individuals.
The number that
represents the largest
amount of individuals an
environment can support at
any one time is the carrying
capacity.

Once populations reach
carrying capacity, they
undergo logistic growth.
What is the difference between
exponential and logistic growth?
What are chemical cycles?

A biogeochemical cycle
is the movement of a
particular chemical
through the biological
and geological, or living
and non-living, parts of
an ecosystem.

They include the carbon,
nitrogen, phosphorous,
water, and oxygen cycles!
The Carbon Cycle

Carbon comes in many
forms, and is essential for
life.

Photosynthesis and
Cellular Respiration play
a huge role in the carbon
cycle by cycling the carbon
dioxide from abiotic to
biotic and back to the
atmosphere.
Water Cycle

Water Cycle explains the change in state of matter for
water from gas to liquid to solid.
The Nitrogen Cycle

The nitrogen cycle relies
heavily on bacteria who
take atmospheric
nitrogen and convert it
to useable forms
(nitrogen fixation) as
well as helping
decompose nitrogen and
return it back to the
atmosphere and soil
(denitrification).
Phosphorous Cycle

Phosphorus’ main reservoir is in rock, however when that
rock breaks down plants can absorb the phosphorus and
animals get their phosphorus from plants.
Eutrophication

Eutrophication- nutrient enrichment
of any ecosystem that is otherwise low
in nutrients


Can occur with any nutrient, but main culprits
are nitrogen and phosphorus
Cause an algal bloom- which kills the other
natural wild life in the area:



Algae/bacteria use up the dissolved oxygen in the
water,
Produce toxins that kill the wildlife
Blocks the sunlight
How does society influence scientific
studies?

What do you think?
How does scientific study influence society?

What do you think?
How do humans affect the
environment?

Air quality


Smog is a type of air pollution
caused by the interaction of
sunlight with pollutants produced
by fossil fuel emissions.
Water quality


Acid rain is a type of precipitation
produced when pollutants in the
water cycle cause rain pH to drop
below normal levels.
Chemical contaminants, raw
sewage, trash, and other waste
products are only a few pollutants
that make their way into rivers,
lakes, and aquifers all over the
world.
How do humans influence biodiversity?

Biodiversity


Loss of Habitat


The wide array and assortment of
species that are found in any
ecosystem.
The loss of habitat can put species
in danger of becoming extinct.
Habitat Fragmentation

Habitat fragmentation occurs
when a barrier forms that prevents
an organism from accessing its
entire home range.

Often, habitat fragmentation is
caused by the building of roadways
or the harvesting of forests.
How do humans impact natural
systems?

Urban sprawl

As cities grew larger, people
moved into suburbs—urban
sprawl.


Suburban growth consumes
farmland and natural habitats.
Global Warming

The trend of increasing temperatures
is known as global warming.
 Sea level rise, global temperature
rise, warming oceans, shrinking ice
sheets, declining arctic sea ice,
glacial retreat, ocean acidification,
and an increase in extreme
weather events are all
consequences of global warming.
Clearcutting and deforestation

Clearcutting, clearfelling, or clearcut logging is a
forestry/logging practice in which most or all trees in an
area are uniformly cut down.

Deforestation is the permanent destruction of forests
in order to make the land available for other uses.
How do humans use renewable
resources?

Resources that cannot be used up
or can replenish themselves over
time are called renewable
resources.


Wind and solar energy are
renewable resources because they
cannot be used up by humans.
Other resources, such as those that
come from plants and animals, can
be used up, but because they could
last indefinitely through re-growth
and reproduction, they are
renewable.
What are invasive species?

An introduces species is any
organism that was brought into
an ecosystem as the result of
human activities.
 Introduces species can pose
a great threat to the stability
of an ecosystem if they prey
on or crowd out native
species.
Burmese pythons are an introduced species
in the Florida Everglades. It feeds on small
animals, such as rats, birds, raccoons, and
even dogs. The same organisms that
alligators feed on. Competition between the
introduced and native species is fierce.
Greenhouse Effect

Define: excessive CO2 in
the atmosphere

Causes:


Increased use of fossil fuels
(coal, oil), non-renewable
resources (another way to say
fossil fuels), clear cutting
(cutting of trees from a
forest)
What can we do?

Increased use of renewable,
clean energy sources such as
solar and wind energy.
What are some conservation
techniques?

Sustainable Practices


Reforestation


Timber companies cut selected trees rather than clear
cutting forests. This encourages rapid re-growth of trees,
and has a minimal impact on the ecosystem.
Fishing Regulation


Sustainable development is a practice in which natural
resources are used and managed in a way that meets
current needs without hurting future generations.
Rotation, gear review, harvest reduction, and fishing bans
are all enforced to help fish populations replenish.
Conservation

Conservation practices focus on a few species but
benefit entire ecosystems.

The listed species is often called an umbrella species because its
protection means a wide range of other species will also be
protected.