ASSIGMENT 10 QUESTIONS There are three lectures to read and study this week. •Lecture 1 is on Ecology (2 files attached) •Lecture 2 is about the Organization of Nature (2 files attached) •Lecture 3 is about Abioitic Factors (2 files attached) After you have read and understood the material in these lectures you will be able to answer the following review questions: • • Well and clear developed each question Complete answers 1.What is the difference between biotic factors and abiotic factors? 2.Define ecology (research the term)? 3.Give an example of an ecotone (other than the ones mentioned in the lecture) 4.Starting with the subatomic particles, list every level of organization, in order, up to the biosphere. 5.What is the difference between an ecosystem and a biome? 6.What is the difference between an endotherm and an ectotherm? 7. What is osmoregulation? 8.What is meant by the windward side of a tree? 9.If you were starting a rose garden what type of additives would you need for the soil? 10.List all of the abiotic factors which were discussed in the lecture notes. ___________________________________________________ Ecology Ecology = the scientific study of the interactions between organisms and their environment. Includes the concern over the destruction of our environment Ecologist • advocate for environmental quality • heads off environmental disorders Environment 1. Adverse effects of human activities on the surroundings 2. Society’s efforts to prevent or alleviate the damage Ecologists • Solve problems caused by increased human population and pollution • Manage and conserve plants and wildlife • Preserve endangered species Aspects of the Environment 1. Abiotic factors non living factors: temperature, light, water, nutrients, moisture, salinity, soil type, etc… 2. Biotic factors living organisms: vegetation animals microbes invertebrates Ecology (Lecture 1) Ecology "Eco" means "house" and, "ology" means "the study of". Therefore, Ecology is the study of the interactions between organisms and their environment. Ecology is a complex area of biology. The term ecology has evolved in definition and encompasses many other items currently. The definition has been expanded to include our concern over the destruction of our environment as well as the solutions to remediate them. Ecologists are advocates for environmental quality and they try to head off environmental disorders. The word environment in ecological terms is encountered in association with: 1. adverse effects of human activities on their surroundings and 2. society’s efforts to prevent or alleviate the damages _______________________________________________________________ _______________________________________________________________ _ Ecologists are involved with solving problems caused by increased human population and pollution; and they manage and conserve the plants and wildlife. In addition, they try to preserve endangered species. _______________________________________________________________ __________ There are two aspects to consider with respect to the environment: 1. Abiotic factors = the non living chemical and physical factors such as temperature, light, water, nutrients, moisture, salinity and soil type. 2. Biotic factors = all living organisms including: Vegetation (from algae to trees) Animals (mammals, birds, reptiles, fish and amphibians) Microbes (bacteria and other microorganisms) Invertebrates (insects) Trees, plants, vegetables, flowers, fruits, etc....are all examples of vegetation. Abiotic Factors (Lecture 3) ABIOTIC FACTORS A. Temperature Most organisms live in temperatures between 32 °F and 113 °F. There are two extremes: 1. At very Low Temperatures: the watery fluid in a cell freezes so, it will rupture and die. 2. At very High Temperatures: proteins in the body will denature (fall apart), become inactive and no longer function. Some organisms can adapt and live outside the normal range (32 – 113 °F). Organisms are classified based on their main source of body of heat: 1. The internal temperature of most organisms is the same as that of the environment. These are the ectotherms. Ectotherms warm their bodies by absorbing heat from the surroundings. For example, invertebrates, fish, reptiles, and amphibians are “cold-blooded”. 2. However, mammals and birds are endotherms. Endotherms derive their body heat from their own metabolism. In other words, endotherms are able to maintain a consistent internal temperature even if the temperature of the surroundings fluctuates. These are the “warm-blooded” organisms which include some fish and insects besides the mammals and birds. B. Water Water is essential to life. Land dwelling organisms are constantly threatened with the possibility of dehydration if they cannot find water. Aquatic organisms (both fresh and marine) need to maintain the same salt concentration inside their bodies as the concentration of water they are swimming in. For example, consider a marine organism living in a body of water that has a 5 % salt concentration. Its cells must also have a salt concentration of 5 %. Different bodies of water have different salt concentrations. Compare Florida’s coastal waters (Atlantic Ocean) with the Dead Sea in Israel which is so salty you can just lie back and float without exerting any effort. If an organism loses its ability to osmoregulate its internal salt concentration it will die. Keep in mind that osmosis is a special type of diffusion which concerns water. The rule is that water always diffuses towards the side that has a greater solute concentration (as if it is attempting to dilute that side and even things out). If the cells of an organism contain a 1% salt concentration and the organism is in a body of water with a 5% salt concentration what happens? Obviously the body of water has a greater solute concentration (5%). So water diffuses out of the cell towards the side with the greater solute concentration. The cells therefore, lose water, they shrink and shrivel up (called the pickling effect or also called crenation) and eventually they die. On the other hand, if the concentration inside the cells of the organism is 5% and the body of water they are in is 1%; now the higher solute concentration is inside the cells. This time the water will diffuse into the cells. The cells gain water, swell and eventually burst and die. This is called lysis. Check out the pictures in the PowerPoints. C. Sunlight Sunlight provides energy for plants and other photosynthetic organisms. This energy drives all ecosystems and accounts for the flow of energy. The sun’s energy is absorbed by the grasses therefore, the energy has been transferred to the vegetation. A cow comes along and eats the grass so now it gets the energy. Humans eat cows so next we get the energy. This is an example of energy flow, however, keep in mind that the amount of energy decreases at each level. Factors which limit the amount of sunlight: 1. Shading In a very dense forest the light energy from the sun does not reach the plant growth on the ground. Therefore, the undergrowth is shaded from the sun and receives much less light than the higher layers. 2. Absorption As one goes deeper and deeper into a body of water, the amount of sunlight is reduced because it has been absorbed by the superficial layers. As a result, photosynthesis only occurs near the surface of the water where there is a greater amount of light energy. 3. Photoperiod The photoperiod refers to the amount of daytime and nighttime. The length of the photoperiod indicates seasonal events. For example, during the long days of summer plants will flower. During the short days of winter birds will migrate. D. Wind 1. The wind-chill factor amplifies the effect of temperature on an organism 2. The wind increases the rate of evaporation in animals and the rate of transpiration in plants 3. The wind inhibits limb growth on the windward side of a tree 4. The wind alters the ocean, pond and lake currents which in turn mix up these bodies of water. The currents up-well the cold, nutrient rich deep sea water and take oxygen from the surface waters down to the bottom. This phenomenon is called Lake Turnover. E. Soil The chemical composition of the soil can either be very rich or poor in nutrients. The pH or acidity of the soil is also important. These factors will affect the distribution of plants and the animals which feed on them. For example, the composition of the sea floor determines which type of organism will reside there. Another example, fruits and vegetables require a certain type of soil in order to grow and thrive. In contrast, flowers like roses require a different pH in order to survive. F. Periodic Disturbances Communities are devastated by fires, hurricanes, tornados, volcanic eruptions, and earthquakes. After such a disaster the structure of the community involved has been drastically altered. It could be repopulated by survivors or it could be colonized by different organisms. G. Climate When we consider all of the previous factors, temperature, water (precipitation), sunlight, wind, and periodic disturbances we speak about the climate of an area. Climatic variations greatly impact the distribution of organisms. Consider an area that receives a regular amount of rainfall throughout the year. This type of precipitation would be conducive to certain plants and animals. Consider another area which may get the same annual average of rainfall but there are distinct wet and dry seasons which effect plant growth and hence the animal population that will reside there. 1. Global Climate Patterns The climate of the earth is determined by both the: a) amount of solar energy which establishes temperature variations, air movements and evaporation and: b) earth’s movement. The earth is tilted permanently on its axis by about 24°. This tilting causes variations in the temperature and light intensity for all parts of the world. As you know, the earth revolves around the sun. In December, the North Pole is tilted as far away from the sun as possible therefore, the Northern Hemisphere is going into winter: the amount of daylight decreases, the days are shorter, the temperature decreases so the days are colder. The South Pole is tilted towards the sun. It is as close to the sun as possible in December. Therefore, the Southern Hemisphere is going into summer: the amount of daylight increases, the days are longer, the temperature increases so the days are hotter. The seasons in the two hemispheres are completely reversed. In June, the complete opposite occurs. Note: the tropical regions are 24° north and 24° south of the equator. In other words, the tropics lie between these latitudes. This area receives direct sunlight everyday of the year so it has the least seasonal variations. At the equator, 0°, the sun is directly overhead giving 12 hours of daylight. Tropical climates have high temperatures, intense sunlight and ample rainfall. All of this yields lush vegetation and coral reefs. Florida is just above this band and so is considered to be subtropical. Because of the way that the air circulates, at about 30° north and 30° south of the equator the air masses absorb moisture from the land. This creates arid climates conducive for the desserts which develop in these regions. 2. Microclimate In a forest, under a rock or log, the climate is moist since evaporation from the soil decreases. This microclimate provides shelter and buffers against temperature and moisture variations. It also keeps predators away. We find salamanders, worms and several types of insects living in harmony in these small areas. Abiotic Factors Abiotic Factors Temperature Water Sunlight Wind Soil Periodic Disturbances Climate 1. Global Patterns 2. Microclimate Temperature Most Organisms: 32°F - 113°F Low T: cell fluid freezes, ruptures and dies High T: proteins denature, become inactive Ectotherms and Endotherms Temperature Ectotherms internal temp same as environment warms body by absorbing heat from surroundings “cold blooded” invertebrates, fish, reptiles, amphibians Temperature Endotherms body heat comes from own metabolism maintain a consistent internal T as T of surroundings fluctuate “warm blooded” mammals, birds, some fish, some insects Osomoregulation 1% 5% 5% Cell looses water Shrinks, shrivels, dies Pickling Crenation 1% Cell gains water Swells, bursts, dies Lysis Water always diffuses to the area of greater solute concentration Sunlight • Provides energy for plants • Drives all ecosytems Factors that affect the amount of sunlight Shading limits plant growth Absorption reduces light in deeper water so photosynthesis occurs at the surface Photoperiods determine length of daytime and nighttime Wind 1. Wind-chill factor amplifies effect of temperature 2. Increases the rate of evaporation/transpiration 3. Inhibits limb growth on the windward side of a tree 4. Alters pond and lake currents which mixes the water. The currents upwell the cold nutrient rich deep water and take oxygen down to the bottom….lake turnover Soil -Rich or poor in nutrients -Consider pH (acidity) -Affects distribution of plants and animals which feed from it Rainfall Compare two areas: Area A: regular amount of rainfall throughout the year Area B: same amount of rainfall but wet and dry seasons Earth’s Movement • Due to the earth’s tilt, there are variations in the temperature and light intensity for all parts of the world • This explains the different seasons • Earth revolves around the sun 10 Causes of the seasons 9 Tropical Regions 24° North and South of the Equator Direct sunlight everyday 24° 24° Florida is just above this band and is considered to be SubTropical 30° North and South of the Equator the air masses absorb moisture creating arid climates = Deserts
Purchase answer to see full attachment