Download Unit A: Biodiversity Science 9 Study Guide

Name______________________________
Unit A: Biodiversity
Science 9 Study Guide
1. Describe the variety of biological species on the earth…
Life exists on our planet in many forms. Biologists have identified over 1.5 million
species of animals, and more than 350 ,000 of plants. They estimate that there is
between 30 – 100 million species of insects.
All these living creatures share certain characteristics
They are made of cells
Need Energy
Grow and Develop
Reproduce
Ability to adapt to changes in their environment
2. What is Biological Diversity?
This refers to all the different types of organisms on Earth.
3. What are the three main components of biological diversity
Biological Diversity is too diverse to study, so Scientists break it down into three
categories
Diversity between Ecosystems
This refers to the huge variety, or diversity, of ecosystems on Earth
Remember that an ecosystem is where biotic factors interact with Abiotic factors in
an shared environment.
Diversity within Ecosystems
This is where scientists study and examine the biotic factors of an ecosystem. Here
they study how species form populations, and how the populations in the same area
form a community
Diversity within Species
This refers to the variation that exists among individuals within a particular type of
species in an Ecosystem
4. What is Variation?
A distinct or distinct form or version of something
These are different traits expressed within and among species
Name______________________________
5. What is co-habitation?
Co-habitation refers to when to when two organisms share/live in the same
environment
Different types of situations that arise from co-habitation are
-Interspecies Competition:
This happens when two or more species living in the same area use the same
resource. It limits the size of the populations of competing species since there is
only so much food or habitat contained in an ecosystem
-Resource Partitioning:
This is when similar species learn to co-exist in the same area. They do this by
learning to use the different resources available to them i.e. the example in your text
on p. 19 where the five warbler birds use different parts of the same tree to supply
their food, and shelter and meet their needs.
This works well since it eliminates competition that would otherwise normally
occur
6. Describe the different types of interdependencies between and among species
Three main types of symbiosis
Commensalism
One organism benefits while the other organism is neither harmed nor benefits
i.e. Orchids growing up high on trees
Mutualism
Both organisms benefit from the relationship
i.e. bee, and a flower
Parasitism
One organism benefits, while the other is harmed
i.e. a mosquito and a human
7. What are niches?
A niche describes the role of an organism within its ecosystem
This includes what it eats and what eats it (where it fits on the food pyramid), its
habitat, nesting site, or range, and how it affects the other population of species
around it.
8. What is natural selection?
Is when the environment “selects” which individuals will survive long enough to
reproduce and pass on their traits
This doesn’t just apply to physical traits, since adaptations can include behavioral
practices as well
Charles Darwin’s theory of survival of the fittest applies to this concept
9. What are heritable traits?
Are characteristics that are passed on from generation to generation
i.e. hair color, height, etc.
Name______________________________
10. What is the difference between continuous and discrete variations?
Continuous Variation are heritable traits that come in a range of forms. They don’t
have a fixed measurement i.e. height, weight, shoe size, skin color.
Discrete Variation are heritable traits that you either have or you don’t have. i.e.
certain eye color, hair color, attached earlobes, hitchhikers thumb
11. How does environment affect variation?
Although environment can’t change the genetic information that you inherit, it can
alter the way you express those traits
Poor nutrition can keep you from reaching your full height or muscle mass
Poor Diet can alter your body weight
Plants that don’t receive enough sunlight won’t grow to their full potential
12. What is asexual reproduction?
It involves only one parent, and all offspring that result from asexual reproduction
are identical to that parent. The offspring is an identical copy to the parent
Different Types
Binary Fission
Budding
Spore Production
Vegetative Reproduction (cuttings, runners, tubers, bulbs, suckers)
Advantages
Simple, produce lots of offspring very quickly with little energy
Disadvantages
Very little variation so if conditions become unfavorable the entire population could
be wiped out
13. What is sexual reproduction?
Involves two individuals, most species of animals and flowering plants reproduce
sexually.
Advantages
Lots of genetic variation, helping to ensure the survival of that species
Disadvantage
Requires lots of energy
Can only produce a limited number of offspring
14. Describe the process of sexual reproduction
It involves specialized cells known as gametes (Ova, Sperm in animals, or Pollen
& Ovules in flowering plants) that come together in union (fertilization).
This cell is called a Zygote that undergoes cell division known a Cleavage
Cell division continues to divide until a Embryo is formed
Name______________________________
15. How do the different types of reproduction affect variation?
Asexual creates an exact copy of the parent, and therefore provides no variation
Sexual reproduction brings together DNA from both parents providing a lot of
variation
16. What carries the genetic information that is passed on from parent to offspring?
Deoxyribonucleic Acid (DNA)
17. What is DNA and genetic code?
DNA is Deoxyribonucleic Acid, is the molecule that contains the inherited genetic
material in the body. It is located in the Nucleus of each cell within a living organism
It forms a double helix (twisted ladder); and it is made up of
-2 X sugar phosphate backbones (outside rails of the ladder)
-4 nitrogenous bases (cytosine, guanine, adenine, thymine) that pair together to
make up the rungs of the ladder
The Genetic Code refers to the sequencing of these four nitrogenous bases that
make up the “genetic alphabet” in order to form words, and instructions (blue
prints) telling the cells what needs to be carried out for survival
It makes it so that all organisms on Earth contain Blueprints in the same language
18. What are genes?
Genes are a specific segment on a DNA molecule that contain a specific sequence of
the four chemical bases (A, G, C, T) that will instruct the body to display a certain
trait. i.e. blue eyes, blonde hair, etc.
Any change in the sequence will result in a potential new gene, or lead to a
malfunctioning of that specific trait and have potential devastating effects
19. How are chromosomes arranged?
Chromosomes are arranged in pairs inside of the nucleus
They are tightly wound molecules of DNA around proteins known as histones
The exact number of chromosomes will depend on which organism you are talking
about
i.e. humans have 46 chromosomes, or 23 pairs of chromosomes
20. Describe mitosis in asexual reproduction
Mitosis occurred in asexual reproduction is known as Binary Fission which results
in a completely new organism. Unicellular organisms only perform it.
The result is a completely new individual that is an exact genetic match to its parent
Name______________________________
21. Describe meiosis in sexual reproduction
Organisms that reproduce sexually use meiosis. Since there are two parents
involved each parent must only contribute half the amount of DNA needed. This
way when fertilization happens the new individual will contains the correct amount
of DNA
It occurs by:
Cell replicates it DNA and splits into two identical cells (just like in Mitosis)
Then those two cells undergo a second cell division without the DNA replicating,
which results in four sex gamete cells each containing ½ the amount of DNA as their
parent cells
This allows the male and female gametes when they combine to provide the new
organism with the correct amount of Genetic material required
Diagrams in your text book p. 47
22. Describe the difference between dominant and recessive traits?
A dominant trait is an allele (copy of a gene) that will be displayed by an individual
organism whenever it is present.
A recessive trait is an allele (copy of a gene) that is present in an organisms DNA, but
overpowered by a different Dominant trait and therefore will not be displayed in
that individual
The presence of Alleles in an organism is due to the fact that they inherit copies of
genes from both parents
23. What other factors affect inheritance of traits?
As well as the things mentioned earlier, nutrition, diet, and environment, other
factors that can affect the inheritance of traits is outside influences such as drugs
and alcohol consumed by the mother during pregnancy
This could result in conditions such as fetal alcohol syndrome, which has
developmental issues on the baby, as well as other drugs that can cause deformities
within the new organism (improper development of limbs)
24. What is extinction?
Is the disappearance of every individual of a species from the entire planet
25. What is extirpation?
Is a term used for local extinction, which is when a species no longer lives in an area
that it use to make home
i.e. the grizzly bears from certain parts of British Columbia
Name______________________________
26. What are extinction and extirpation caused by?
Can be either natural or caused by humans
Natural Causes
-Catastrophic events such as volcanic eruptions, floods, or fires
-Lack of food due to overpopulation
-Diseases
-Overspecialization (the species cannot adapt to the changes occurring in its
ecosystem)
Human causes
-Habitat Destruction
-Introduction of Non-native species (thrive since they have no natural predator in
their new ecosystem
-Over Hunting
27. What is artificial selection?
Is the process of selecting and breeding individuals with desirable traits to produce
offspring that contain these same desirable traits
This is where the idea of pure breeding comes into play, since breeders will only
breed to animals that both contain the same traits
28. Describe the technologies that affect biological diversity
Artificial Insemination: is where sperm is harvested from the male animal, and
then inserted into the female taking the need for the actual sexual act out of
equation, and allowing the organisms sperm to be in more places at once
impregnating more females
In Vitro Fertilization: This is where the sex gametes from both the mother and
father are extracted, and fertilization occurs in a petri dish in a lab resulting in an
embryo. The embryo is then implanted back into the animal or another organism of
the same species where the offspring will develop
Genetic Engineering: Refers to any technology that directly alters the DNA of an
organism
Here scientists will specifically insert a specific gene that they would like organisms
to express. These new products are known as GMO’s (genetically modified
organisms).
i.e. because bacteria reproduce so quickly scientist have inserted the gene that
creates insulin, so that insulin can now be produced by bacteria to enable that we
have a suitable quantity at a reasonable cost
29. What biological conservation strategies are being used to preserve diversity?
Protection of Areas/Ecosystems. I.e. National Parks
Restoration of Ecosystems and Species. When action occurs to restore an
Ecosystem, or regenerate the population of a particular species
Resource Use Policies: when laws are passed to help protect a species
Controlling the spread of Exotic Species: Controlling bioinvasion either by
preventing the species from entering the country, or by taking care of the outbreaks
occurring
Conservation of Genetic Resources: Conserving the genetic information outside
of the natural habitat. i.e. Seed Banks allow scientists to ensure that species of
plants that no longer exist can be brought back if required