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
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.
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
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
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
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