Biology 1 1 - Final Exam 4
What are some strategies for increasing populations for conservation? The most common are creation of protected areas, captive breeding and reintroduction, conservation legislation, and increased public awareness.
The most common are creation of protected areas, captive breeding and reintroduction, conservation legislation, and increased public awareness.
What role does biodiversity have on ecological communities and ecosystems?
Ecological life support—biodiversity provides functioning ecosystems that supply oxygen, clean air and water, pollination of plants, pest control, wastewater treatment and many ecosystem services.
What are the 4 major abiotic components of climate?
Four Major abiotic components of climate: Sunlight Temperature Water Wind
Use the various trophic levels to describe food webs and energy flow in a system. How efficient is energy transfer between trophic levels? What happens if certain organisms disappear from a food web?
How efficient this energy transfer is between producers and consumers is called trophic efficiency. In general, depending on the food web, trophic efficiency ranges between 5-20%. For the simplified food chain shown in the figure below, the trophic efficiency, the percent of production transferred from one trophic level to the next, is 10% (as also shown in the video above!).
Radial Symmetry
Any image slice creates a mirror image
What leads to seasonality?
The Tilt of the Earth on it's axis as it orbits the sun
What factors need to be ideally incorporated into reserve design?
Finally the recognition of multiple stakeholders and the need to manage reserves as complex systems has been prioritized. The goals for reserve design include the 4 Rs: representation, resiliency, redundancy, reality. The figure below illustrates such an approach.
Describe key adaptations of animals that allowed tetrapods to evolve into more terrestrial habitats.
-legs to support the body's weight outside of water, -lungs to extract oxygen from air, -redesigned heart and circulatory system to drive larger muscles, -reproduction that prevents egg from drying out (arises in amniotes), -system to prevent whole body desiccation.
What are the various species interactions that can be present in communities? Are these interactions positive, negative, or neutral?
Cause many aspects of a species' niche includes other species, one of the major factors that affects community structure and function are species interactions. These interactions may be negative, positive or neutral and may change over time.
What role does disturbance play in maintaining biodiversity? Explain your answer.
Disturbance is an important ecological process that influences species diversity and composition. It is typically defined as a discrete event in time that causes change to resource availability, the physical environment, and ecosystem, community, and/or population structure.
What are the distinguishing characteristics of Phylums Porifera and Cnidaria? How does structure inform function in these organisms?
Porifera lacks vascular tissue and no true organ system In contrast to sponges, cnidarians feature a tissue level of organization since cells are organized into specialized tissues. However, there are no true organ systems (e.g. circulatory, excretory, or nervous).
What is the greenhouse effect and how is this related to global warming?Why is it said that invasive species lead to "biotic homogenization?" What are the potential major impacts of invasive species?
The greenhouse effect is the way in which heat is trapped close to Earth's surface by "greenhouse gases." These heat-trapping gases can be thought of as a blanket wrapped around Earth, keeping the planet toastier than it would be without them. And as carbon dioxide has increased from anthropogenic sources, so has global temperatures, as shown in the figure below of the keeling curve. Invasive species impacts may include Habitat alteration, Altering community dynamics, Out-competing natives, Changing ecological processes, Introducing disease.
The endoderm ("endo-" = inside)
The innermost cell layer, lines the developing digestive tube and gives rise to the digestive tract and organs derived from it, such as the liver and lungs of vertebrates;
The difference of Animals From protists
- All Animals are multicellular -Animals are Heterotrophic eukaryotes that digest and absorb released nutrients from their gut that is continuous with outside environment - Cells in Animals are Specialized because they develop from an embryo to an adult (Early development stage)
What four characteristics do all chordates share?
A dorsal Hollow nerve cord A notochord Pharyngeal Gill Muscular post anal taill
How do sources, sinks, and fragmentation play a role in metapopulations?
A metapopulation is a regional population that is made up of subpopulations in habitat patches ("suite of populations within landscape"). Populations dynamics are such that individuals may move into or out of subpopulations, and these habitat patches may act as a source or sink. Source populations are generally in favorable areas that produce a lot of seeds or organisms and potential emigrants. A sink, on the other hand, are populations that occupy unfavorable habitats that must receive a constant influx of immigrants to maintain itself. Fragmentation of habitats can alter dispersal between habitat patches, turning source populations (larger habitats originally) into smaller patches that might be dispersal sinks (especially for seeds dispersed by specialists). Watch the video below to learn more about the effects of fragmentation and seed dispersal in Columbian Forests.
Bilateral Symmetry
A single slice through the midline of the body results in mirror-image left and right sides
What are the various scales of ecology and what questions might be asked at each level?
Auto Ecologist - may be interested in studying the physiological ecology of an organism and might ask questions about where and when photosynthetic rates are the highest Population Ecologist - might ask different questions that concern population dynamics. Community - is an assemblage of all of the populations of organisms (includes different species) living close enough together for potential interaction. A community ecologist may be interested in interspecies interactions. For example how does herbivory by animals affect the distribution of our Himalayan blue poppies?
Given a diagram of a biogeochemical cycle, interpret the relative importance of reservoirs and fluxes. In any integrated system, fluxes connect reservoirs together to create cycles and feedbacks
Biogeochemical cycling is the cycling of water and nutrients between biotic and abiotic components. These organic and inorganic resources are known as the pools (or reservoirs) and the movement of material between them is known as flux. The rates of cycling ("flux") between these reservoirs is affected by environmental conditions (e.g. temperature, pH) and community dynamics.
What are the three different types of spatial dispersion? Under what circumstances would populations exhibit each type of dispersion pattern?
Clumped Dispersion - This arises when there is an attraction between individuals Uniform Dispersion - Nearly uniform distributions arise as a result of territoriality or stiff competition for some essential resource, as you can see with penguins or when male song sparrows sing to defend their territories during mating season. Random dispersion: Random distributions arise when habitat conditions are nearly uniform, resource availability is constant, and there are neutral interactions between individuals of a population, such as with some "weedy" plants like dandelions! In this type of dispersion, individuals are not affected by the locations of other individuals so there is no pattern (unlike the previous two dispersion patterns, where an individual's spatial distribution is affected by other individuals!).
Identify distinguishing characteristics of Phylum Arthropoda and Echinodermata and their respective classes.
Exhibits Bilateral Symmetry / have a hard exoskeleton made mostly of chitin. Arthropods have jointed appendages (e.g. legs, mouth, antennae, wings) and their bodies are arranged in specialized groups of body segments Their respective classes are : Chelicerata, Myriapoda, Crustacea and Hexapoda
What are some approaches for ecosystem conservation?
One strategy is to conserve genetic diversity by long-term storage of seeds (pollen and tissue too) in seed banks or botanical gardens. Material is stored in cool, dark conditions to prevent germination and ideally contains specimens that are representative of geographic and genetic diversity. Today ~10,000-20,000 of the world's plants are stored in seed banks. Pictured below is a seed storage room.
What are the different ways ecologists describe communities?
One way that we can describe a community is by describing the different types of species that occur in it and their relative abundance and dispersion. In some communities, one or a few species may be most abundant and dominate that community. For example sage scrub communities are dominated by sage bushes and redwood forests have most of their biomass held in the trunks of the redwood trees. We can also describe communities by their diversity, the variety of organisms that make up the community. Diversity encompasses many biotic scales and can be described in terms of:
Name the three different types of mammals. How are they similar/different?
Placental Mammals - Complete embryonic development Marsupials - Give birth to tiny underdeveloped embryos. Monotremes - Tiny egg laying mammals. they have a single orifice for urination, defecation and reproduction!
Distinguish between Phylum Platyhelminthes, Nematoda, Annelida with respect to coelom , movement and appearance.
Platyhelminthes (Flatworms)- Lacking coelem , waves of Cilliary action , Ventrally flattened. Nematoda (Roundworms) - Pseudocoelem, contraction of longitudinal muscles, Cylindrical with blunt head and tapered tail Annelida ( "Segmented worms) - Coelom, extending the body, closed circulatory system. .
What are the core principles of conservation biology? Why should we conserve biodiversity?
Preserve diversity of species and biological communities, Prevent extinctions of populations and species, Maintain ecological complexity and ecosystem functions, Avoid the loss of genetic diversity, Allow evolution to continue, Consider the intrinsic value of biological diversity
Describe the similarities and differences between the two types of ecological succession.
Primary succession: starts on an area with no vegetation/soil (e.g. on volcanic flows, glacial till). Secondary succession: starts on an area that has soil/vegetation (e.g. burnt forest, disturbed area, changes due to species interactions).
What is a Biodiversity Hotspot and how is this concept useful for conservation?
Regions are designated Biodiversity Hotspots if they have both high endemism (endemic is a species that is unique to a particular area) AND are at high risk from human impact. In other words, these are places where conserving species will have a large impact in securing global biodiversity. These areas represent ~2.3% of earth's terrestrial surface, as you can see in the figure below (note: California Floristic Province was designated a "biodiversity hotspot" in 1996).
What is ecosystem restoration?
Restoration is the return of an ecosystem to a close approximation of its condition prior to disturbance. One of the earliest examples of restoration was the tall grass prairie at University of Wisconsin by Aldo Leopold (see figure below). He is known as the father of restoration ecology and viewed the natural world "as a community to which we belong. That land is a community is the basic concept of ecology, but that land is to be loved and respected is an extension of ethics."
Describe the main body parts of a Mollusc that defines this phyla. Are these parts present in gastropods, bivalves, cephalopods and chiton? Explain your answer.
Soft Body(Visceral mass), Muscular foot(Functions in locomotion), Mantle ( Fold of tissue that drapes over visceral mass and secretes a shell) The Parts are present. Gastropod(snails/slugs) have stomach foot while bivalves are mantle, cephalopods are Mantles.
How is exponential growth similar/different from logistic growth? What factors contribute to each growth pattern?
The exponential growth model predicts the maximum rate at which a population could increase in number under ideal conditions. Sometimes it is referred to as the "intrinsic rate of growth model" because growth is only limited by how fast an organism can reproduce (per capita rate of increase). For example, in the graphs below, you see growth rise fairly quickly in what I like to call a "J-shaped" curve.
What are predictions for climate change and what are some biological consequences?
There are several consequences of climate change. Simply put the predictions of climate change include: Increased temperatures, Changing hydrological cycles (wetter and drier), Shifting Hadley cells, Increased storm intensity and frequency.
Describe the various influences that can affect the size and density of populations.
These population Dynamics are influenced by: Environmental Conditions Resource Availability Competition Disturbance Availability of Propagules. (Biogeography)
Describe the major global climate patterns, include temperature, precipitation and winds. How do these interact to lead to the major the water and terrestrial biomes (give an example for each)?
This differential heating of the earth also sets up large scale climatic patterns across latitudes called Hadley Cells (see figures below). As moist air warms up at the equator, it begins to rise and cool, causing it to lose moisture. The air reaches the upper atmosphere and then travels north and south, cooling along the way until it descends at ~30°N and ~30°S. The descending air is dry and cool and spreads along the earth warming up and gaining moisture as it moves back to the equator and toward the poles. At ~60°N and ~30°S, the warmed moist air rises again, dropping rain as it cools. The cooling air travels along the upper atmosphere and eventually descends at the poles and at ~30°N and ~30°S.
Describe the three types of survivorship curves and the factors that might contribute to having one type over another.
Type I curves are typical for large animals that bear few offspring and give extended parental care, such as in hippos, buffalos, and elephants. Type II curves indicate that old individuals are just as likely to die of disease or predation as young ones, which you might see in salamanders, robins, and squirrels. Type III curves are typical for species that produce many small offspring and provide little to no parental care, such as when sea urchins or fish release millions of eggs into the water, in which most of them get eaten.
Why are we considered to be in the 6th Mass Extinction?
Unfortunately, the loss of biodiversity is accelerating and the main causes are humans and habitat destruction.
Identify the 3 subphyla of Phylum Chordata and list any key similarities and differences.
Urochordata (Tunicata), Cephalochordata and Vertebrata
Describe key strategies in restoration ecology. What is adaptive restoration an important approach to restoration ecology?
encouraging natural processes to speed up restoration, translate scientific insights into management to speed up processes of recovery. Adaptive Restoration (Incorporating experiments into restoration to advance the understanding of restoration of a particular site and to inform the science of restoration ecology, as well as the basic ecological theory. The ocean is a large carbon sink and has served to buffer increased inputs of carbon dioxide. However, the consequences of this are increased ocean acidification.
The mesoderm ("meso-" = middle)
forms the muscles, skeleton, and most other organs, such as those in the respiratory and circulatory system.
The ectoderm ("ecto-" = outside)
gives rise to the outer covering of the animal and in some phyla, to the central nervous system;
What are the major threats to biodiversity?
habitat loss, invasive species, overharvesting, pollution, climate change
Coelom
is a fluid-filled space between the digestive tract and outer body wall in which internal organs are suspended and The coelom helps to protect suspended organs from injury.
