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Biological Diversity and Survival
Lesson 1: Diversity & Species
- An ecosystem is any place on Earth in
which living (biotic) things interact with
other living things and non-living (abiotic)
things
Ex. Marshes, lakes, forests, desert, arctic
- Organisms have different characteristics
or variations.
- The number and variety of organisms in
an ecosystem is called biological
diversity
- Each organism plays a role in the food
chain and within the ecosystem
ex. Mosquitoes, although they are
annoying and can transport diseases, they
are food for dragonflies, etc.
SPECIES: the smallest group in which all
organisms have a very similar set of
characteristics
Biologists also define species as a group
of organisms that interbreed in nature, and
whose offspring are able to breed.
Ex. Lions and tigers are able to interbreed
in zoos, but their offspring are sterile.
Therefore they are different species. They
do not interbreed in nature since they live
in different habitats
Offspring are called:
Ligers – if father is a lion and mother is a
tiger
Tigons – if father is a tiger and mother is a
lion
- When members of a species live in a
specific area and share the same
resources they form a population.
- When populations of different species
live in the same area, they form a
community.
Diversity within Species
- In some species, the young are much
different looking than the adults: change
is called metamorphosis.
Ex. Tadpole – frog, grub-beetle,
caterpillar- butterfly
- In some species, the males look different
than the females: sexual dimorphism
ex. Humans, peacocks
- In some species, there are several
different looking forms: Polymorphism
ex. Ants: queen, worker, soldier
Bees: queen, drone,
Speciation: - over time a new
characteristic may develop within a
species. This results in the formation of a
new species
- Over several generations, organisms
will adapt to increase their chances of
survival
- Some adaptations are Structural
Adaptations
- Ex. Gills to get oxygen
- Some adaptations are Behavioural
Adaptations
- Ex. Nocturnal organisms; migration
- Variation within species is important so
that entire populations, communities,
and ecosystems are not wiped out by a
single catastrophe.
- For example a disease may destroy one
species of tree, but the others will
remain unharmed.
Lesson 2 - DIVERSITY INDEX
Compares the diversity of species in an
area with the total number of organisms in
the same area. The closer to “1” the
greater the diversity.
Tropical areas tend to have a higher
diversity index, since there is more water,
a greater variety of food, etc.
ex. Mexico – 293 different species of
snakes
United States – 126 species of snakes
Canada – 22 species of snakes
Over population, pollution, hunting, etc.
may result in a lower diversity index
How to Calculate the Diversity Index
1. Starting with “A” assign each organism
that you see a letter.
2. If the second organism is the same as
the first, assign it the same letter ex. A,
A
3. If the third organism is different than
the first and second assign it the letter
“B” ex. A, A, B
4. Every time you come across an
organism that is different from the last
one, assign it a new letter.
5. Each change starts a new “RUN” of
data
6. Determine the number of runs, by
counting how many different letters you
used.
7. Count the total number of specimens in
your trial.
Diversity Index = Number of Runs
Number of Specimens
e.g. A,A,A,B,C,C,C,C,D
Diversity Index = 4/9 = 0.44
The Niche
- The term niche describes the role of an
organism within the ecosystem
- An organism’s niche includes 2 parts where it lives and what it does
- Adaptations allow an organism to play a
specific role in its environment
- ex. Producers - produce own food
usually through photosynthesis
Herbivores -eats only producers
Carnivores - eats only consumers
Omnivores - eat producers and
consumers
Decomposers - breakdown dead
organisms an organic material;
release nutrients
- Organisms that live in the tropics,
where there is lots of food and stable
temperatures, are SPECIALISTS
and have a Narrow Niche
- They are well suited to one particular
environment
- This allows a number of different
species to inhabit the same area, but
prevents them from moving to new areas
- Organisms that are able to survive in the
harsher Canadian climate in general have
a BROAD NICHE (they have adaptations
that allow them to survive the wide range
of temperatures)
GENERALISTS can live almost
anywhere
When introduced into a new area where
there are too few predators, generalists
spread rapidly often taking over, and
forcing out the indigenous species
Competition occurs when there are
limited resources,
and more than one organism needs the
same resource
- Can occur between members of the
same species or between different
species
- Variations between individuals may give
one of them an advantage (better chance
for survival)
- The less successful species may have to
change its habitat or use a different food
source
- As organisms change to avoid or reduce
competition they alter their niches
- This increases the variation within or
between species
Symbiotic Relationships
- When 2 organisms live in direct contact
- there are three types
(a) Mutualism – BOTH partners benefit
(b) Commensalism – ONE partner
benefits, and the other neither benefits nor
loses
ex. A bird builds a nest in a tree.
(c) Parasitism – One partner benefits and
the other is harmed
ex. A tapeworm attached to the
intestinal wall of a human, robbing the
human of nourishment. They do not kill
their hosts because the hosts represent
their food supply
Lesson 3: Reproduction
Two types:
1.
Asexual Reproduction
- Involves only one parent
- All offspring are identical to the parent
- Common among bacteria and fungi
Advantages: No need to mate
Occurs quite rapidly
No specialized cells
required
Disadvantages: all cells are exactly the
same; anything that kills one will kill
them all
Types of asexual reproduction:
a) Binary Fission
– Cell duplicates its contents and then
splits in half
- Only occurs in one-celled organisms like
amoeba, bacteria, and some algae
b) Asexual Spores
- Similar to seeds, but are produced by the
division of cells on the parent
- Many spores are produced to ensure
survival of some
- ex. Mushrooms, green algae, ferns
c) Budding
- parent produces a small bud, or smaller
version of itself
- the bud eventually detaches and
becomes a new individual identical to its
parent
- ex. Yeast, hydra
d) Vegetative Reproduction
- Growing tips of roots and stems contain
areas of rapidly reproducing cells called
MERISTEM
- Can take a cutting of a plant, and the
meristematic cells will produce a
new plant that is a CLONE of the
parent
- Strawberries and spider plants send out
runners that produce new plants along
them - Suckers from trees
2.
Sexual Reproduction
- Requires 2 parents
- Genetic material supplied by both
parents, therefore the offspring are not
exactly like either one
- Fertilization occurs when an egg (female
gamete) unites with the sperm (male
gamete)
- Produces a cell containing genetic
material from both called a ZYGOTE
Advantage: increases the variation in the
species, which helps the species survive
environmental changes
Disadvantage: takes longer and requires
2 organisms
Assignment:
Describe the following terms:
Specialist
Metamorphosis
Niche
Species
Diversity index
Abiotic
Structural adaptations
Biological diversity
Commensalism
Polymorphism
Budding
Variations
Population
Mutualism
Lesson 4 - Sexual Reproduction in
Plants
- Angiosperms (flowering plants) and
Gymnosperms (coniferous trees)
reproduce by producing seeds.
PISTIL- female reproductive organ
-is made of the stigma, style and
ovary
OVULE – contains the egg, and is found
in the ovary
at the base
of the pistil
STAMEN – male reproductive organ
- is made of the anther and
filament
POLLEN – each pollen grain contains a
sperm nucleus that was produced on the
ANTHER of the stamen
POLLEN TUBE – the pollen grows an
extension that grows into the pistil until it
reaches the ovule
EMBRYO – the zygote undergoes cell
division to produce a multicellular embryo
COTYLEDONS – supply food to the
embryo
-Some organisms are capable of both
sexual and asexual reproduction
ex. Grass
Bacteria Conjunction
- Bacteria are able to transfer genetic
material directly from one cell to another
- Primitive form of sexual reproduction
since 2 parent cells are required
- Results in genetic recombination but not
reproduction, since there is no increase in
number of cells
- This process is followed by binary
fission, when the new recombined genetic
material is passed along
Sexual Reproduction in Animals
- Both male and female gametes must
arrive at the same place at the same time
for fertilization to occur
- The zygote requires specific conditions
to develop
- Requires a liquid environment to
prevent drying and gives the sperm a fluid
to swim through to reach egg
- Animals such as clams and sponges use
external fertilization. Therefore live in
water
- Mammals carry out internal fertilization
- In most mammals the embryo develops
close to or within the female
Lesson 5: Genetics
- Genetics is the study of heredity
- Non-heritable characteristics are
acquired/learned. ex. Piano playing,
language
- Heritable characteristics are passed on
from generation to generation ex. Eye
color, hair type, skin color
- Variations in traits can be either
(a) Continuous
– Differences that have a range
of forms
ex. Skin color, height, hair color,
hand size
(b) Discrete
- Differences in characteristics
have a limited number of
possibilities
- ex. Tongue rolling, sex, blood
type, hand clasping
- GENES control these inherited
characteristics or TRAITS
- Each gamete contains thousands of
GENES
- For each trait there are at least 2 genes:
one from the mother and one from the
father
- Any gene that affects the same trait is
called an ALLELE
- One type of allele is usually
DOMINANT, and the other type is
RECESSIVE.
- The dominant one will hide the effects
of the recessive
ex. If brown fur is dominant to white
fur and a mouse has one gene for brown
and one for white, it will have all brown
fur
- Recessive genes may show up in later
generations
ex. 2 brown mice may have white
mice
- The frequency of a trait does not indicate
it if is dominant
- The frequency of a trait can vary from
population to population
Examples of dominant and recessive traits
Dominant
brown eyes
tongue roller
dimples
detached earlobes
widows peak
peak
middigital hair
Recessive
blue eyes
non tongue roller
no dimples
attached earlobes
no widows
no hair
Pure Breed - if both alleles for a trait are
the same (both dominant and both
recessive)
Hybrid – if they have one dominant and
one recessive allele for a trait
Assignment #5:
p. 25 – key terms
p. 25 #2, 5
p. 36 #1 (copy question)
Punnett Square – used to predict the
appearance of offspring
- we use a capital letter for the dominant
gene and a lower case letter for the
recessive gene
Ex. Brown mouse gene – B
Albino mouse gene – b
Father - Pure Breed Brown (BB)
Mother - Hybrid Brown (Bb)
-each parent passes on one gene for colour
Father
Mother
B
B
B
BB
BB
b
Bb
Bb
Off Spring – 50% pure bred brown
50 % hybrid Brown
Construct a Punnett Square for a hybrid
brown father and a hybrid brown mother.
Indicate the percentage of each type of
offspring.
Activity: Observing Human
Characteristics (Page 38)
Homework: Vocabulary Review; Topic
1-3
Construct a Punnett square for the
following trait in cats and indicate the %
of each type of offspring
Father – pure bred black fur
Black fur - B
Mother – pure bred white fur
White fur - b
Lesson 6: Factors Affecting Genetic
Information
- Some characteristics depend entirely on
genetic information that is passed along to
the offspring – nature.
Ex. eye color
- Some characteristics depend entirely on
the environment – nurture.
Ex. Scars,
makeup
- Some characteristics are combinations of
genetic and environmental factors
Ex. Weight, ability to hear notes,
height of plants,
- Genetic information can be changed by
factors in the environment and by random
errors
-These changes to the genetic material are
called MUTATIONS
X-rays, U.V. Rays, Cosmic
rays and some chemicals
called MUTAGENS can
cause mutations
Ex. Cancer cells are mutated cells,
which can interfere with nearby cells and
prevent the body from performing
normally
Cancer cells go through rapid
cell divisions and do not develop in the
same way
- If mutations occur in the gametes, the
changes may be passed on to the child
- These changes in the genetic material
increase the variation within a species
Lesson 7: DNA (DeoxyriboNucleic Acid)
- All living things are made up of cells
- Inside the cell is the nucleus, which
contains DNA.
- DNA is the material responsible for
inheritance of different traits
- DNA has the shape of a coiled ladder
(see p. 47)
- The sides of the ladder are made of
smaller molecules called sugars and
phosphates
- The rungs of the ladder are pairs of
nitrogen bases (nucleotides)
A – adenine
T – thymine
G – guanine
C – cytosine
- The arrangement of these 4
chemicals forms a code that cells can read
just like the 26 letters of the alphabet can
be arranged to form words that we can
read
- This GENETIC CODE is like a blue
print that controls the production of
proteins in the cell
- CHROMOSOMES are tightly coiled
strands of DNA
- Each cell must have a complete set of
chromosomes in order to have all the
genetic information needed
-Each human cell nucleus contains 23
pair (46) of chromosomes.
- A section of the DNA molecule that
codes for a specific protein and function is
called a GENE.
Mitosis (Cell Division)
– In order for an organism to grow and
repair or replace tissues, the cells must
divide. Cell division is also called
mitosis.
- Body cells are called SOMATIC
CELLS.
- Human body cells have different life
spans
- Brain cells last 30 – 50 years
- Skin cells only last 20 days
- Before division can occur the
chromosomes containing the genetic
material must duplicate (make a copy of
itself)
- When the cell divides, each half gets a
complete set of chromosomes. The 2 new
cells are genetically identical to each other
and to the original cell
http://www.edumediasciences.com/a70_l2-mitosis.html
Meiosis
- Is a type of cell division that produces
cells with only HALF of the DNA of a
normal cell.
- These cells produced are called
GAMETES - sperm and egg cells.
- When a sperm cell (23 chromosomes)
fertilizes an egg cell (23 chromosomes)
the resulting ZYGOTE has 23 pair (46)
chromosomes
- In humans it is the 23rd pair of
chromosomes that determines the sex of
the child
- XX – female
with 1 “X”
- XY – male
“X” and 2 “Y”
produces 4 eggs each
produces 4 sperm 2
- Therefore it is the male that determines
the sex of the child (50/50 chance)
http://www.lewport.wnyric.org/jwanamak
er/animations/meiosis.html
Lesson 8: Genetic Variations
- Asexual reproduction occurs very
rapidly, and requires little energy
- Therefore lots of offspring are produced
- The offspring are genetically the same as
the parent
- If conditions become unfavorable, the
entire population can be wiped out
- Sexual reproduction takes longer, and
requires more energy
- Fewer offspring are produced
- Offspring have received genetic
information from both parents; therefore
there are variations, which increase the
chances for survival
Biotechnology
- Genetic engineering has allowed
scientists to move genes from one
organism to another to produce traits that
are more desirable, and increase the
chances for survival
- ex. Move the human gene for insulin
into bacteria, allowing the bacteria to
produce insulin as a waste product
This allows us to produce insulin in large
quantities for diabetics.
- Animals can also be given human genes
- Adding human genes to the fertilized
eggs of the animal produces these
TRANSGENIC animals
- The offspring grow up with the human
gene, and are able to produce human
proteins, which can be obtained through
the mammal’s milk
- Aquaculture is used in fish production
to add genes for disease resistance to
some varieties of fish
- Growth hormone genes have also been
added to fish eggs to increase the size and
growth rate
- Run the risk of transgenic fish escaping
into the wild and the natural fish
populations not being able to compete
with the genetically altered fish
- The transgenic fish may grow too
quickly for the resources to support them
- Many crops such as wheat, corn,
potatoes etc have been genetically altered
to be tolerant of herbicides
- This allows farmers to spray the crops,
killing the weeds but not the crop
- However, if there is cross-pollination
with wild weeds, it can result in weeds
that are resistant to herbicides
- Crops have been engineered to survive
different climates
- This means that the same crop can be
grown anywhere
- Although new varieties are produced, the
widespread use of the new varieties could
result in the elimination of the whole crop
by disease or pests
- Taking a cutting from a plant and
growing an identical plant from the
cutting can produce plant clones.
- A faster method is to take cells with the
desired traits and grow them in a petri
dish until the cells develop into a seedling
and can be transplanted (What else is
needed in the petri dish?)
Lesson 9: Artificial Selection
- Artificial selection is the process of
selecting and breeding individuals with
desirable traits to produce offspring that
have these desired traits
- Many DOMESTIC animals are bred for
specific traits
e.g. Breed dairy cows for most milk
production
- ARTIFICIAL INSEMINATION is
often used to produce offspring with
desired characteristics
- ex. Bulls and cows – more cows can be
inseminated
- INVITRO FERTILIZATION involves
taking sperm from a prize bull and eggs
from a prize cow and fertilizing the egg in
a petri dish
- Many more embryos are formed
- Each embryo is implanted into a
different cow
- Eventually they give birth to many
calves, all brothers and sisters
- They can decide to only implant female
embryos if they are trying to increase their
dairy cattle
Selective Breeding in Agriculture
- Taking seeds from the healthiest or best
producing plants to sow the following
year
- May want wheat that is high in protein,
or matures faster, or more resistant to cold
temperatures, insects or disease.
Natural Selection
- In 1831 Charles Darwin began a 5-year
trip on the H.M.S. Beagle - he stopped at
many isolated islands.
- By comparing animals he came up with
his theory of Natural Selection
1. All organisms’ produce more
offspring than can possibly survive
2. There is incredible variation within
each species
3. Some of these variations increase the
chances of an organism surviving to
reproduce
4. Over time, variations that are passed
on lead to changes in the genetic
characteristics of a species
- We say that the environment “selects”
which will live
- “Survival of the fittest”
Ex. In a family of rabbits,
possibly only one in ten
will survive to reproduce.
The one that survives may
have been the fastest or the
smartest or the best
camouflaged or the best
dodger or some
combinations of all of
these.
The Sixth Extinction?
- There have been 5 major declines in
biodiversity in the past
(see p. 66 - graph).
- Areas of plentiful heat, light and rainfall
have a greater abundance of plant life,
which leads to more complex food chains
and therefore greater biodiversity
- Degradation of these ecosystems has
resulted in extinction of different species
Extinction – the disappearance of every
individual of a species from the entire
planet
- Scientists estimate that 99% of all
species that ever existed are now extinct
- Reduces the number of species on the
planet
Extirpation – the extinction of a species
in certain locales (areas).
Ex. Grizzly bears from Mexico and
most of U.S.
- Reduces biological diversity in an
area
- Natural events such as volcanoes,
earthquakes, ice age , forest fires can
cause extinction or extirpation
-Lack of food due to overpopulation,
disease and overspecialization have also
resulted in extinction
Ex.
Dutch Elm Disease,
American Chestnuts
(fungus)
Giant Panda – only eats
bamboo (can’t switch)
- Most extinctions however are not
natural, but a result of human activity
- Until the mid 1800’s the world’s
population was less than one billion
- By 1930 the population had doubled and
by 1960 it was at 3 billion
Two Main Factors were responsible for
this human population explosion
(a) Improved Sanitary Conditions
- Sewage treatment, water
treatment and food handling, as well
as improved medical treatment for
diseases increasing life expectancy
(b) Industrialization
– Rapid production of materials,
rapid
transportation and farm
mechanizations
Industrialization meant new industries
starting
up and people moving near the industries
for work resulting in URBANIZATION
(cities).
- Industrialization means more materials
are taken from the environment
- Good farmland is used to build cities
- More natural habitats are being cleared
for farmland
- Logging
- Damming of rivers
- More pollution
- Use of pesticides, herbicides, and
fertilizers
-Developing nations are often hardest hit
by population explosions
- Damage to the rainforests is difficult to
repair since forest soil has few nutrients
and prevents re-growth of the forest
- Civilization and urbanization have
resulted in the loss of various habitats
- Air pollution has created problems such
as global warming
- Changes in temperature may result in
extinction of specialists that are unable to
adapt to the temperature changes
- The loss of large carnivores, such as
bears and wolves is considered to be a
bioindicator.
- These animals are known as
bioindicator species.
- Hunting of animals such as the wooly
mammoth and the passenger pigeon have
resulted in their extinction
- The loss of one species can result in
other species being endangered since the
food chain is affected
- Today greater efforts are made to
preserve the natural habitats and prevent
over-hunting and over-fishing
Lesson 12: Preservation
- Zoos are part of a worldwide network
attempting to protect and preserve
endangered animals
- Animals are exchanged between zoos to
maintain genetic diversity of the species
In-situ conservation – maintenance of
populations of wild organisms in their
functioning ecosystems
Ex. Banff National Park – established
in 1885
-1st national park in Canada originally only
around the hot springs
- Seed banks – used to gather and store
seeds from plants that are threatened with
extinction
- Some are commercial ventures;
governments or universities for research
run others
- Stored at –20 °C and a few seeds of each
sample are germinated every ten years
- Global Treaties are established to
protect endangered plants and animals
- 1975 Convention on International Trade
of Endangered Species (CITES) makes it
illegal to buy or sell endangered animals
or animal parts
- 500 species were identified for
protection
-180 countries have signed the 1992
Convention on Biodiversity and have
agreed to set up protected areas for
threatened and endangered species
- Groups such as Canadian Wildlife
Federation and Canadian Nature
Federation educate the people and lobby
governments for more action
Assignment:
p. 78 #1-4
p. 79 – key terms
Unit 1 Test is on Tuesday, Sept. 30.
Assignment: Unit Review on pages
84 to 87:
#
2, 4, 5, 6, 11, 12(b), 13,
17, 24, 28, 34, 36, 38
(copy questions)
Lesson 19: Review
Presentation of remaining projects
Review Page 85-87
# 13-18,23,24,28,38,42