Limitations of Dichotomous Keys and Alternatives

A dichotomous key examines physical characteristics and may use technical terms that can be confusing for users.

One method is making comparisons with specimens in reference collections, where expert taxonomists identify unknown specimens by comparing them to known ones.

DNA surveying improves classification by sequencing DNA and comparing it to known sequences, allowing for more accurate identification when physical characteristics are insufficient.

<p>A species is a group of organisms that share common characteristics and can interbreed to produce fertile offspring.</p> Signup and view all the answers

<p>One limitation is that it does not account for asexually reproducing organisms, making it difficult to classify them as species.</p> Signup and view all the answers

<p>Geographically isolated populations may not interbreed, yet the biological species concept does not clarify if they belong to the same species.</p> Signup and view all the answers

<p>The biological species concept does not classify extinct populations, making it difficult to apply this definition to fossilized organisms.</p> Signup and view all the answers

<p>Temperature and soil moisture.</p> Signup and view all the answers

<p>They determine the environmental conditions necessary for survival and reproduction, limiting species to areas where these conditions are met.</p> Signup and view all the answers

<p>Position the rain gauge in an open area and check it daily at the same time, recording the amount of collected rain in a graduated cylinder.</p> Signup and view all the answers

<p>Percentage frequency measures the number of organisms of a particular species in an area, while percentage cover measures the proportion of an area covered by that species.</p> Signup and view all the answers

<p>Find the area covered by the organisms in all quadrats, calculate the area of one quadrat as a percentage, and then multiply that percentage by the number of quadrats occupied by the species.</p> Signup and view all the answers

<p>Intraspecific competition occurs between members of the same species, while interspecific competition takes place between different species.</p> Signup and view all the answers

<p>An ecological niche describes the specific set of abiotic and biotic conditions and resources an organism or population depends on, including food type and environmental conditions.</p> Signup and view all the answers

<p>If two species occupy the same niche, the one with a faster growth rate and more efficient energy use will outcompete the other, potentially leading to the latter's extinction.</p> Signup and view all the answers

<p>A J-population growth curve shows exponential growth without limiting factors, typical of microbes and small mammals that can experience rapid population increases.</p> Signup and view all the answers

<p>An S-population growth curve includes limiting factors that slow growth until the carrying capacity (K) is reached, typical of larger mammals.</p> Signup and view all the answers

<p>Carrying capacity (K) is the maximum population size that an ecosystem can sustainably support based on its available resources.</p> Signup and view all the answers

<p>Limiting factors are conditions that slow down population growth as it approaches carrying capacity, which can be biotic or abiotic.</p> Signup and view all the answers

<p>Predators kill and eat their prey, while parasites weaken their host without killing them directly, influencing population dynamics.</p> Signup and view all the answers

<p>Stronger individuals have higher reproductive success, leading to a greater share of resources and potentially dominating the population.</p> Signup and view all the answers

<p>Species can coexist in overlapping niches if they have different needs, but excessive overlap may lead to competitive exclusion.</p> Signup and view all the answers

<p>Predation is when one animal, the predator, kills and eats another animal, the prey. An example is lions eating zebras.</p> Signup and view all the answers

<p>Herbivory involves animals (herbivores) eating plants, while predation involves predators eating other animals. An example of herbivory is cattle feeding on grass.</p> Signup and view all the answers

<p>Mutualism is a relationship where both species benefit. An example is leguminous plants and nitrogen-fixing bacteria.</p> Signup and view all the answers

<p>Competition occurs when two species vie for the same resources, resulting in negative effects on both. An example is lions and hyenas competing for food.</p> Signup and view all the answers

<p>Limiting factors slow population growth by causing equilibrium through resource scarcity, disease, waste accumulation, and competition.</p> Signup and view all the answers

<p>Saprotrophism is the feeding on dead organic material, such as by earthworms. It is important for nutrient recycling in ecosystems.</p> Signup and view all the answers

<p>J-curves experience rapid population decline or crash due to limiting factors like seasonal climate change and overexploited resources, unlike S-curves which stabilize.</p> Signup and view all the answers

<p>Density-dependent factors vary with population size, such as disease and competition, while density-independent factors affect population regardless of size, like extreme weather events.</p> Signup and view all the answers

<p>Population size is estimated using the formula $\frac{M*N}{R}$, where M is the marked first sample, N is the second sample caught, and R is the recaptured marked individuals.</p> Signup and view all the answers

<p>Predation helps control prey populations, ensuring resources are sufficient for survival, while predators benefit from a food source. It also maintains a healthy gene pool in prey species.</p> Signup and view all the answers

<p>The method used is capture, mark, release, recapture, which involves marking organisms, releasing them, and then resampling later.</p> Signup and view all the answers

<p>Disease harms the host species, affecting their function and survival. It can also regulate population sizes and maintain ecological balance.</p> Signup and view all the answers

<p>Both involve one species benefiting at the expense of another; however, predation results in the death of the prey, while parasitism may not kill the host immediately.</p> Signup and view all the answers

<p>Non-conspicuous marking helps to prevent predation, ensuring marked organisms survive in their environment.</p> Signup and view all the answers

<p>Marked organisms may experience stress or altered behavior, potentially affecting their quality of life or the study's outcomes.</p> Signup and view all the answers

<p>Factors include the number of trials, type of traps used, the marking method, and assumptions about organism distribution.</p> Signup and view all the answers

<p>'Trap shy' behavior could lead to underestimation of the population size if fewer marked organisms are captured during the resampling.</p> Signup and view all the answers

<p>Seasonal variations may lead to fluctuations in population density, affecting the number captured and thereby skewing estimates.</p> Signup and view all the answers

<p>Habitat density variation means that not all areas are equally populated, which can lead to inaccurate assumptions about the population structure.</p> Signup and view all the answers