Biology SAC Checklist U2AOS2 PDF

+-----------------------------------------------------------------------+ | **Chapter 9A: Sexual vs Asexual Reproduction** | | | | **Genetic diversity:** the amount of genetic variation that exists | | be...

+-----------------------------------------------------------------------+ | **Chapter 9A: Sexual vs Asexual Reproduction** | | | | **Genetic diversity:** the amount of genetic variation that exists | | between individuals. | | | | - - - - | | | | **Asexual Reproduction:** | | | | - - - - - - - | | | | **Fission:** a single parent cell divides into two approx. equal | | parts, which develop into a new organisms | | | | - | | | | | | | | - | | | | **Budding** - similar to fission, except division of cytoplasm is | | unequal, occurs in unicellular organisms like yeast​ | | | | - - | | | | **Fragmentation** - similar to fission, but happens in multicellular | | organisms | | | | - - - | | | | **Spore Formation/Sporogenesis** - occurs in some organisms like | | fungi​, can either be asexual or sexual | | | | - | | | | **Spores** = cells encased in a protective coating that enables them | | to survive in unfavourable conditions | | | | - - - | | | | **Conidia:** spores, produced by budding, are called conidia​ | | | | - | | | | **Parthenogenesis:** where an embryo can develop from a single | | unfertilised gamete, only in females | | | | - | +=======================================================================+ | **Chapter 9B: Cloning** | | | | Somatic cell nuclear transfer (SCNT) involves two different cells: a | | donated egg cell & a donated somatic cell from another animal.​ | | | | 1\. **Enucleation:** removal or destruction of the nucleus from the | | donated egg cell to produce an enucleated (cell that has had its | | nucleus removed or destroyed) egg cell​ | | | | 2\. **Extraction:** donated somatic cell's nucleus is extracted​ | | | | 3\. **Insertion:** somatic's cell is inserted into the enucleated | | egg cell​ | | | | 4\. **Development:** the cell begins to divide & develop into an | | embryo, which is then implanted into a surrogate mother. The | | pregnancy then continues as normal. | | | | \- The offspring produced is genetically identical to the donated | | somatic cell as they both contain the same nucleus & genetic | | material. | | | | **Applications of SCNT (horticulture & agriculture):** cuttings & | | grafts​, tissue culture​, embryo splitting​, nuclear transfer​ | | | | **Advantages:** Can enhance desirable traits in plants & livestock, | | disease research, increasing population of endangered species | | | | **Disadvantages:** susceptibility to disease, high failure rate, | | adverse health effects, ethical & moral issues, less genetic | | diversity | | | | **Nuclear transfer:** Remove nucleus from unfertilised egg & replace | | it with nucleus from an adult somatic cell, used in reproductive & | | therapeutic cloning (e.g., Dolly the sheep). | | | | **Embryo splitting:** Splitting an early-stage embryo to create | | identical organisms, used in agriculture | | | | **Gene cloning:** Copying specific genes or DNA sequences, used in | | medicine, biotechnology, research | | | | **Molecular cloning:** Using plasmids & vectors to clone DNA in | | bacteria or yeast, used in protein production, vaccines, research. | +-----------------------------------------------------------------------+ | **Chapter 10A: Adaptations for Arid Environments** | | | | **Adapting to the desert - animals:** | | | | - - | | | | **High SA:V ratio:** releases or absorbs a proportionally large | | amount of heat in little time - quick changes in body temp | | | | - | | | | **Low SA:V ratio:** releases or absorbs a proportionally low amount | | of heat & their internal body temp is resistant to change | | | | - - | | | | | | | | - - - - - | | | | **Increased water input:** drinking the dewfall that occurs at night, | | metabolic production of water during aerobic cellular respiration | | | | - | | | | **Decreed water output:** excrete concentrated urine containing very | | little water, extremely long loop of Henle in the nephron | | | | - - | | | | **Evaporative cooling:** release huge amounts of heat via the | | evaporation of water e.g. sweating, panting | | | | - - - - | | | | **Behavioural adaptations - evaders:** generally smaller animals that | | modify their behaviours to avoid extreme temps & high internal body | | temps. | | | | **Behavioural adaptations - endures:** generally larger animals that | | don't avoid extreme temps. | | | | - - - - - - | +-----------------------------------------------------------------------+ | **Chapter 10B: Adaptations for Cold Environments** | | | | **Structural adaptations:** | | | | - - - | | | | **Physiological adaptations:** | | | | - - - | | | | **Vasoconstriction:** when the diameter of small blood vessels in the | | skin & overall blood flow is reduced, body sends signals to constrict | | these blood vessels | | | | - | | | | | | | | - | | | | **Behavioural:** reducing exposed surface area (e.g. hiding or | | protecting the peripherals as temps drops, huddling, seeking shelter | | e.g. burrows, bens, rocky outcrops, migrating to a warmer climate | +-----------------------------------------------------------------------+ | **Chapter 10C: Interdependence Between Species** | | | | **Trophic levels:** | | | | Primary Producers (Autotrophs): Plants and algae that produce their | | own food through photosynthesis. | | | | Primary Consumers (Herbivores): Organisms that eat primary producers. | | | | Secondary Consumers (Carnivores and Omnivores): Organisms that eat | | primary consumers. | | | | Tertiary Consumers: Predators at the top of the food chain that eat | | secondary consumers. | | | | **Keystone species:** an organism that plays a crucial role in | | maintaining the structure, diversity, and functioning of an | | ecosystem. | | | | - | | | | **Apex predator:** a predator that has no natural predators and is at | | the top of its food chain.​ | | | | **Ecosystem engineer:** an organism that creates, significantly | | alters, or maintains the structure of an environment.​ | | | | **Population density:** the number of individuals per unit of area or | | volume. | | | | **Population:** a group of organisms of the same species living in | | the same geographic region -\> described by distribution, size, | | density | | | | Population growth - natality, mortality, immigration, immigration | | | | Independent factors of population size & density - sunlight, | | humidity, water availability, natural disaster, human changes | | | | Dependent factors of population size & density - competition, | | predation, crowding, parasitism | | | | **Niche:** the role or function of an organism within its ecosystem | | e.g. its behaviour & interaction w/ other species | | | | **Beneficial interactions:** mutualism (partnership), obligate | | mutualism (dependent on each other), facultative mutualism (benefit | | but do not rely on each other) | | | | **Symbiosis:** species living in close partnership | | | | **Benign interactions (species are unaffected):** commensalism | | | | **Harmful interactions:** parasitism, amensalism (one is | | inhibited/harmed, the other is unaffected e.g. cows & vegetation), | | predation | | | | **Predator-prey relationships:** crucial role in maintaining | | ecosystem balance by regulating population sizes and driving natural | | selection. | +-----------------------------------------------------------------------+ | **Chapter 10D: Indigenous Knowledge of the Australian Ecosystem** | | | | Country - viewed as a living thing, Country well managed = healthy, | | poorly managed Country = 'sick' and requiring human intervention | | | | - - - - - - - | +-----------------------------------------------------------------------+ | **Notes:** | +-----------------------------------------------------------------------+