Download Unit A: Biological Diversity

Topic 1: Survival and Diversity
Biodiversity: The number and variety of organisms. An area with high biodiversity (lots of different species and
interactions) is better able to survive if the environment suddenly changes.
Variation: differences within a group of similar living things. No two organisms are exactly alike, even those in the same
species. Variation allows for greater chance of survival of a population when faced with change.
Ecosystem: any place in which living (biotic) things live and interact with other biotic and abiotic (non-living) things
Species: One type of plant or animal. Two organisms are the same species if:
 They are able to interbreed in nature
 Their offspring are able to reproduce
 Example: A horse and a donkey are both species. A mule (the offspring of a horse and donkey) is NOT a
species, since it cannot reproduce.
Population: members of a same species living in a specific area and sharing resources
Community: populations of different species living in the same area
Index of diversity: Compares the diversity of species in an area with the total number of species in that area.
Adaptation: species adjust to the surrounding conditions
1. Morphological or Structural: Physical Change
2. Behavioural: Change in behaviour (ex: migration, night hunting…)
Practice Questions:
1.
Which of the following is an example of variation within a species?
a) Darwin studied different species of finches that had different styles of beaks.
b) Different students in a classroom have blue, brown, or green eyes.
c) A forest consists of pine, spruce and poplar trees.
d) Black bears and grizzly bears share the same meadow
2.
Which of the following statements is correct?
a) A community refers to the same species living in an area.
b) A community consists of non-living things in the same area
c) A population refers to all living things in an area.
d) A population consists of members of the same species.
3.
Which of the following is likely NOT a structural adaptation?
a) A species of bird has eyes almost on top of its head, to see predators more easily when feeding
b) Geese migrate south for the winter, as food sources become scarce
c) The eyes of cats have many rod cells, which gives them excellent night vision
d) Rabbits’ fur changes color depending on the season: brown in summer, and white in winter
4.
Biological diversity is important for the following reason(s):
a. many medicines come from biological sources
b. the survival of one species is sometimes closely related to the survival of another
c. biological diversity may promote the health and survival of natural communities
d. all of the above
5.
Which of the following is NOT an example of a behavioral adaptation?
a) Robins make their nests in trees
b) Owls hunt at night for food
c) Eagles have hollow bones to make flight easier
d) A possum “plays dead” to avoid predators
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Topic 2: Habitat and Lifestyle
Niche: A niche is the organism’s job or role in the environment or ecosystem. (Where it lives and what it does!)
Examples ...
 A hawk’s role is a predator in the environment
 A fungus’s role is the breakdown of decaying matter in the environment
 A poplar tree absorbs light for photosynthesis, releases oxygen into the air, provides food and shelter
Broad Niche: Very little variety of species, but large populations of those that are present.
Organisms are generalists, they must be able to wide variety of environmental conditions to survive.
Examples …
 In the Canadian North, you find very few species (elk, bear, moose, wolves) but large populations of them.
 These animals can adapt to temperature change, eat a wide variety of food
Narrow Niche: In areas of the world where conditions (food source, temperature) are stable, you have a large variety of
species but small populations
Organisms are specialists, they have adaptations that make them well suited to survive in a particular
environment. So well in fact, that they cannot survive in another environment. (trap of specialization)
Examples ...
 Tree monkeys are specialized for life in the forest canopy (trees). It is not suited for life on the ground. If the
forest gets cut down, the tree monkey will not be able to survive.
Biodiversity increases the closer you approach the more stable conditions near the Earth’s equator.
Dependency: Organisms in any given environment depend on one another for their basic needs. These relationships
can include symbiosis, predation, general or specific types of relationships.
o Symbiosis is a close relationship between two different organisms over time. It can be mutual, which means
that both organisms benefit from the interaction.
o Predation is where one organism kills another.
o Interspecies Competition: a type of relationship between organisms where neither one benefits. It happens
when 2 or more species need the same resources.
Practice Questions:
1.
Which statement best describes the niche of a wolf in Alberta?
a) The wolf, found throughout the boreal forests and mountains of Alberta, is a predator feeding on
herbivores.
b) The wolf, found in the mountains of Alberta, is a producer of food
c) The wolf is a predator feeding on deer and moose.
d) The wolf lives exclusively in Banff National Park in Alberta.
2.
Which of the following make up an organism’s niche?
I.
The amount of competition from other organisms.
II.
The habitat of the organism.
III.
The functions performed by the organism in the environment.
IV.
The country in which the organism is found.
V.
The size of the organism’s population.
a.
b.
c.
d.
3.
I, II, and V
II and III
II, III, and V
II, IV, and V
Which organism would be considered a specialist?
a) Wolf
b) Toucan
c) Arctic rabbit
d) Polar bear
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Topic 3 - Reproduction
Asexual reproduction does not involve the union of male and female sex cells but is actually the transmission of the
same genetic information from a parent to its offspring. Basically the offspring is an exact copy of the parent.
1. Binary Fission: Asexual reproduction found in single cell organisms where the genetic information is copied
and the cell divided into two identical cells equal in size.
Example: An amoeba, paramecium, or other single celled organism
2.
Budding: The formation of a bud on an organism which grows to become a new organism independent of
the parent. Its DNA is identical.
Example: Hydra
3.
Spore Production: Production of a hardcoat seed-like structure, but are produced by the division of cells of
one parent and not the union of two sex cells.
Example: Mushrooms and fungi
4.
Vegetative Reproduction: Involves only plants where a new plant can be formed from the vegetative parts
of the parent.
Example: Runners on a strawberry
Sexual Reproduction involves the union of male and female sex cells and requires two parents. Offspring are different
because they have characteristics of both parents.
1.
Bacterial Conjugation: This is the primitive type of sexual reproduction. One bacterium grows a tube-like
structure and passes on a copy of its DNA to another bacterium.
Example: bacteria
Illustration:
2.
Plant and animal reproduction: This involves two parents whose sex cells undergo a process called meiosis
where the DNA of each parent is divided in half and transmitted to the offspring. The offspring receive half of
the genetic information from each parent.
 Example: Humans have 46 chromosomes and a person gets 23 chromosomes from their mother and
23 chromosomes from their father.
 Sexual reproduction in plants and animals involves the joining of male and female sex cells called
gametes. Gametes have ½ the chromosomes of regular cells.When sperm and egg meet, they form
a zygote. As the zygote develops after many cell divisions, it is called the embryo. In animals, an
embryo is a multi-cellular organism during early development.**How many chromosomes are
there in a zygote? In an embryo?
Sexual Reproduction:
Advantages
Disadvantages
Asexual Reproduction:
Advantages:
Disadvantages:
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Plants: Male reproductive organ = the stamen
Female reproductive organ = the pistil
Animals:
Conditions necessary for fertilization:
 Gametes need to be at the same place at the same time
 Gametes need humidity, nutrition, heat and protection
Internal fertilization has a high rate of success because it protects the embryo from the climate and from predators.
Examples: Humans, mammals
External fertilization poses extreme risk because gametes could be eaten by predators or washed away by the currant.
They can also be subjected to extreme temperature, come in contact with pollutants or be deprived of oxygen. The
majority of gametes are lost or destroyed.
Examples: Salmon
Some organisms can reproduce both ways:
 Ferns: makes both spores and zygospores
 Yeast can reproduce by both budding and sexual reproduction.
 Plants: Plants can reproduce by making seeds. Seeds are made by the union of sperm cells within a pollen grain
and an egg cell produced by the ovary of the female plant structure. Plants can also reproduce by cuttings, suckers,
runners, and bulbs. Example: asparagus, potatoes, spider plant
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Topic 4 – Genetic Variations
Continuous variation:___________________________________________________________________________
Example: There is a range of hair colour or eye colour, height, etc.
Discrete variation ____________________________________________________________________________.
This means that there is limited ways of showing this trait.
Example: Straight thumb or bent back thumb (2 possibilities)
Roll your tongue or can’t roll your tongue (2 possibilities)
Pointed hairline or straight hairline (2 possibilities)
Blood type (4 possibilities: A, B, AB, O)
Dominant : traits are expressed or visible in the offspring.
Recessive: an inherited trait that shows up in the offspring only if that trait is passed to the offspring by both parents.
When mixed with dominant traits, the recessive trait does not show up.
Incomplete or intermediate dominance: Red and white snap dragons can produce a pink snap dragon. The offspring
gets chromosomes from each parent that enable it to produce both white and red pigments. The expression of one is
not dominant over the other therefore an intermediate colour is produced.


Purebred: refers to a plant or animal whose ancestors all with the same form of a trait
Hybrid: an organism created by crossing two purebred parents
Heritable: Heritable traits can be passed on from parent to offspring. Example: Your eye colour is inherited from your
parents, however a scar is not.
Non-heritable: non-heritable traits cannot be passed to offspring. Example of environment vs. genetic: Height and
weight are largely determined by genetics but a person’s diet can affect how heavy they become.
Why are twins studied to determine heritable vs. non-heritable traits?
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
Mutation: _____________________________________________________________________________________
Causes of mutations:
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Topic 5: DNA, Cell Divisions and Technology
DNA ________________________________________________________________________________________
_____________________________________________________________________________________________
A chromosome _______________________________________________________________________________
Every cell has ____ chromosomes except your gametes – they have ________.
A gene is a section of DNA on a chromosome that codes for a specific protein and function.
An allele is a variation of a gene. Ex: White and red colours are variations or alleles that are codes for pigment in snap
dragons.
Structure of DNA: “_________________________”. It looks like a coiled ladder. The sides are made of alternating
units of sugar and phophate. The rungs are pairs of nitrogen bases:
Adenine always pairs with Thymine.
Cytosine always bonds with Guanine.
Cell Divisions
Before any cell division, chromosomes are copied. Then, one or the other type of cell division is accomplished to make
new cells.
Mitosis- A mother cell (____ chromosomes) divides into two identical daughter cells (____ chromosomes).
MITOSIS INVOLVES BODY CELLS; NO VARIATION (new cells are identical to the original)
Meiosis – A mother cell (____ chromosomes) divides into 2 daughter cells (____ chromosomes) which then re-divide
without copying their chromosomes to create 4 new cells (____ chromosomes). The ____ chromosomes divide
randomly and evenly into the cells. The result of meiosis is sex cells – the gametes. Males produce sperm and females
produces ovules. THERE ARE TWO ROUNDS OF CELL DIVISION IN MEOISIS. MEOISIS RESULTS IN
SEX CELLS (sperm or egg), aka “gametes”.
Technologies to change DNA:
 Cloning
 Genetic engineering (taking the genes from one organism and inserting them into another, to give
desirable traits to that organism)
 Artificial reproduction techniques
 Food and medicine production
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Topic 6 – Selection
Natural Selection: _______________________decided which organism survives to reproduce and pass on their traits
to the offspring. Ex: Those which resist disease, famine, environmental disasters such as hurricanes and tornadoes.
Examples: being able to resist disease, famine, disasters; the evolution of beak shapes
Darwin’s Theory of Natural Selection: Survival of the fittest! The best adapted organisms survive the environment.
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, the variations that are passed on lead to changes in the genetic characteristics of a species.
Example: long neck in girafes.
Artificial Selection: _________________________ decided which traits will be passed on to offspring. (aka selective
breeding). Artificial selection has been used for much longer than genetic recombination techniques.
Ex: Pears, apples, dogs, cats, dairy cows, wheat.
The big question: Why is selection necessary? Is selection related to biological diversity?
Complete questions 1-5 on page 65.
Topic 7: Extinction
How do humans affect biological diversity?
Extinction is the disappearance of every individual of a species from the entire planet. Example: the dinosaurs
Extirpation is the disappearance of a species from a particular area. Example: the grizzly bear from the prairies.
Grizzly bears are now only found on mountains.
Natural Causes
Artificial Causes
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Topic 8 – Conserving Diversity
Topic 8
How do we protect/conserve biodiversity?
EX-SITU METHODS
1.
Zoos
2.
Seed Banks
IN-SITU METHODS
3.
International Treaties
4.
Protected Areas (i.e. National Parks)
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