ISB 202 1nd EditionExam # 2 Study Guide Lectures: 8-12Lecture 8 (February 6)Describe energy flow through a typical food chain – a food chain has linked feeding series. Each source only has one source of food. It is not complicated like a food web.What are the laws of thermodynamics? – 1. Energy cannot be created nor destroyed, only converted. 2. No energy conversion is 10% perfect. There will be a net loss of energyHow do they impact the diversity and numbers in the various trophic levels? – Heat energy is given to producers (plants) and they give off heat as well. They are also eaten, so that energy that came to them from the sun is given off to primary consumers (herbivores), and so on. What is the pyramid of biomass? – The pyramid of biomass is a pyramid with the total biomass of all producers, herbivores and carnivores. The biomass of producers is the largest, at the bottom of the pyramid. Then, herbivores are next followed by carnivores.What are biogeochemical cycles? – Biogeochemical cycles are the circulation pathways of essential elements (carbon, phosphorus, nitrogen, water, oxygen) Clearly describe the stages in each cycle – Hydrologic Cycle (pathway of water): solar energy evaporates water that is in plants and oceans. It rains via precipitation. Runoff of water goes into oceans, but also it can be evaporated. Transpiration happens when plants give off water from leaves and soil to the environment. Nitrogen Cycle: Nitrogen re-enters the environment through death of organisms and secreting urine. Haber Bosch Process: Under high heat and high pressure, nitrogen and hydrogen make ammonia. 1% of the world energy supply is used for this process. Phosphorus Cycle: Needed to make DNA and ATP (energy). We mine phosphorus from rocks and minerals. Producers take in phosphorus, we eat it and decomposers put it back into the environment. It takes a long time.Carbon Cycle: Intake of CO2 during photosynthesis and release of C during respiration. Burning fuel gives a lot of carbon and it cannot all be used. This gives excess carbon dioxide that contributes to global warming.In what ways have humans impacted these cycles? We impacted the nitrogen cycle by using fertilizer (it’s explosive, poisonous, and feeds 1/3 of the world), nitrogen fixing crops and fossil fuels. Lecture 9 (February 11)Describe the events that lead to Darwin developing and explaining evolution through the mechanisms of natural selection – The Galapagos island finches. They lived on different parts of the islands and had different adaptations to survive in their environment.What is the best explanation for describing and defining the process of evolution? – Changing in allele frequency over time to better survive in your environmentWhat is meant by the quote “Nothing in biology makes sense except in the light of evolution?” – The basis of all biology questions can be answered using evolution theory. Evolution creates a starting point for questions to arise and be answered. Why are we all so similar? EVOLUTIONWhat is meant by fitness? - An organism’s lifetime reproduction. If you have high fitness, you will survive and produce people like you that will survive. The weak will not reproduce and will become extinct. FITNESS IS ALL THAT MATTERSWhat is artificial selection? – Breeding for certain traits (woof woof puppies) What is an Adaptation? – A trait that increases fitnessWhat is meant by survival of the fittest? – Herbert Spencer said that it is not survival of thestrongest, but the ones more adapted to survive in their environment.What is reproductive isolation? – factors that prevent two members of the same species from reproducing How does a new species arise? – Crossing over of genes over time. OR for example, a natural disaster causes a species to split up and they have to adapt to their new environment so much that they change into two totally different species. How much mass extinction has occurred in the past? – about 5 different occasionsWhat are two major theories explaining how evolution has occurred? – Natural selectionis gradual and nonrandom. An organism can pass down any traits it has to its offspring. Lecture 10 (February 13)What is gradualism? Punctuated Equilibrium? – Gradualism is a gradual selection. Change happens gradually. Punctuated equilibrium happens when spurts of change happen. Change will happen, then there will be a long period with no change, then there will be change again…What are some of the major misconceptions about evolution? – Evolution is only a theorythat hasn’t been proved, it hasn’t been observed, etc.What are examples of selection pressures? – As time goes on a specific trait may be selected against, even though in the past it wasn’t. The environment gives the selection pressures. It causes advantages and disadvantages to different traits.What is sexual selection? – reproducing and choosing a mate based on attractive traits What is natural selection? – Evolution where more fit organisms have offspring that survive and the less fit don’t. This causes people to look less like their ancestors. It is descentwith modification. Where do differences come from? – Differences come from mutation. Mutation is change in the DNA sequence by chance (mistakes in replication, exposure to radiation, etc)What is the gene pool? – Gene set given to the individuals of a given population. How do deleterious mutations, such as the point mutation that causes sickle cell anemia,continue to be passed on? – Sickle cell is passed on in some parts of Africa because it is selected for to help get rid of malaria. Describe the evidence that is used to support evolution – Galapagos finches, fossils, geological formations Lecture 11 (February 18)What is convergent evolution? Give examples – independent evolution of similar adaptations in unrelated species that live in the same environment. (thorns in different plants, FOXP2 gene in birds and humans)What is a habitat? – Where you live (address)What is a niche? – What your role is community: what you eat and what eats you (occupation)What are the ways species interact? – predator/prey, symbiosis, competitionWhat is coevolution? – The process where the evolution of one organism drives the evolution of another organism. When predator and prey evolve together. This maintains a high level of fitness in a specific gene What is Batesian and Mullerian mimicry? – Batesian:
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