Plasma estrogen levels reach their peak at the end of the luteal phase of the ovarian cycle.

a. True
b. False

Answer:

Explanation:

The spores of some fungi are dispersed in water or on the surface of water. The chemical composition of the wall of these spores makes them "non-wettable" so they won't sink. The spores are carried along on the surface of the water like little boats. Water in the form of raindrops can disperse spores in a different way. While gravity is not a primary means of spore dispersal, evolutionary adaptations have been required of many fungi to overcome gravitational effects for effective spore dispersal. SPORE DISPERSAL BY WIND Dispersal of fungal spores by wind is by far the most common method for terrestrial fungi.

Answer: The three main research methods used are observation, modeling, and experimentation.

Explanation:

Observation:

Every experiment requires observation. Ecologists must observe the environment, the species within it, and how those species interact, grow and change. Different research projects different types of assessments and observations.

Ecologists sometimes use a desk-based assessment, or DBA, to collect and summarize information about specific areas of interest. In this scenario, ecologists are using information already collected from other sources.

Oftentimes, however, ecologists rely on observation and fieldwork. This entails going into the habitat of the subject of interest to observe it in its natural state. By doing field surveys, ecologists can track the population growth of species, observe community ecology in action and study the impact of any new species or other introduced phenomena in the environment.

Each field site will differ in nature, shape, or other ways. Ecological methods allow for such differences so that different tools can be used for observations and sampling. It is crucial that sampling be done randomly to combat bias.

Modeling:

Ecological methods rely heavily on statistical and mathematical models. These provide ecologists with a way to predict how an ecosystem will change over time and react to changing conditions in a system.

Modeling also provides another way to decipher ecological information when fieldwork is not practical. There are several drawbacks to relying solely on fieldwork. Because of the typically large scale of fieldwork, it is not possible to replicate experiments exactly. Sometimes even the lifespan of organisms is a rate-limiting factor for fieldwork. Other challenges include time, labor, and space.

Modeling provides a method in which to streamline information more efficiently.

Examples of modeling include equations, simulations, graphs, and statistical analyses. Ecologists use modeling for producing helpful maps as well. Modeling allows for calculations of data to fill in gaps from sampling. Without modeling, ecologists would be hampered by the sheer amount of data that needs to be analyzed and communicated. Computer modeling allows for comparatively rapid analysis of data.

A simulation model, for example, enables the description of systems that would otherwise be extremely difficult and too complex for traditional calculus. Modeling allows scientists to study coexistence, population dynamics, and many other aspects of ecology. Modeling can help predict patterns for crucial planning purposes, such as for climate change.

Humanity’s impact on the environment will continue. It, therefore, becomes ever more crucial for ecologists to use ecological research methods to find ways to mitigate the effects on the environment.

Experimentation:

The overarching purpose of ecological methods for research is to get high-quality data. Experiments must be carefully planned.

Hypothesis: The first step in any experimental design is to come up with a hypothesis or scientific question. Then, researchers can come up with a detailed plan.

Factors that affect fieldwork experiments include the size and shape of an area that needs to be sampled. Field site sizes range from small to very large, depending on what ecological communities are being studied. Experiments in animal ecology must take into account the potential movement and size of animals.

For example, spiders would not require a large field site for study. The same would be true when studying soil chemistry or soil invertebrates. You could use a size of 15 meters by 15 meters.

Herbaceous plants and small mammals might require field sites of up to 30 square meters. Trees and birds might need a couple of hectares. If you are studying large, mobile animals, such as deer or bears, this could mean needing a quite large area of several hectares.

Deciding upon the number of sites is also crucial. Some field studies might require only one site. But if two or more habitats are included in the study, two or more field sites are necessary.

Tools: Tools used for field sites include transects, sampling plots, plotless sampling, the point method, the transect-intercept method, and the point-quarter method. The goal is to get unbiased samples of a high-enough quantity that statistical analyses will be sounder. Recording information on field data sheets aids in the data collection.

A well-designed ecological experiment will have a clear statement of purpose or question. Researchers should take extraordinary care to remove bias by providing both replication and randomization. Knowledge of the species being studied as well as the organisms within them is paramount.

Results: Upon completion, collected ecological data should be analyzed with a computer. There are three types of ecological experiments that can be made: manipulative, natural, and observational.

Hope This Helps!

The 3 general methods used by ecologists to study organisms include:

Observation involves observing organisms in their natural habitats or environments and then recording the findings. It is usually done by field surveying.

The different species living in an environment, how they interact with each other and other abiotic components of the environment are some of the observations taking during field surveys. The growth of individual species, the effects of introducing new species, their adaptations and other areas of community or ecosystem ecology can be studied through observation.

Modelling requires a simulation of real-life ecological processes through  different manipulations. This could be done in the laboratory, on the field, or even on the computer. Computer modelling requires that data from observation or experimentation are supplied as input and the inputs are subject to mathematical maneuvering.

With models, complex ecological processes can be simulated and analyzed and extrapolated to deduce how things might happen in real life ecological interactions.  

Experimentation involves setting up experiments following the scientific method. It can be a observational or controlled experiments.

Observational experiments requires studying organisms, populations, communities, or ecosystems through pure observation without changing or manipulating any variable.

Controlled experiments requires that variables are introduced and manipulated in some groups while some groups serve as the baseline without any manipulated variables.

Data are obtained from experiments and these are analyzed in relevant ways to support or reject hypotheses.  

More on ecological studies can be found here: https://brainly.com/question/22875048

Answer:

Abductor hallucis

Explanation:

Abductor hallucis: A muscle on the inner side of the foot that runs from the big toe to the heel, it pulls the big toe, or hallux, away from the body. Tibialis anterior: This muscle runs from the tibia to the first toe, and helps make walking possible by flexing the foot upward and turning it inward.

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Answer:

inside the phage ghosts outside the bacterial cells.

Explanation:

According to Hershey & Chase- Experiments, the radioisotope 35S is frequently associated with protein since sulfur is a protein component.  The radioactive sulfur is absorbed into the protein coat because it already contained sulfur (35S).  The radioactive marker 35S was integrated into the Bacteriophage protein coat and remained as phage ghosts outside the bacterial cells.

Answer:

Variation

Explanation:

Migration into a population from other populations with varying gene frequencies, evolution, or adaptation of heat tolerance is a cause of variation. The allele frequency of the resulting hybrid population would be right in the middle of its original value and the donor population's frequency. In tropical and subtropical ecosystems (Sahara deserts), high temperatures are a significant restriction to human population productivity; they induce morphological and physiological modifications at all times, resulting in significant yield losses but the ability and evolution of human species to cope in this region is as a result of variation.

Answer: A. The amount of heat created by the star.

Explanation: The Hertzsprung–Russell diagram, abbreviated as H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their stellar classifications or effective temperatures. Your Welcome

Answer:

1

Explanation:

Lichen are usually the first thing to grow on bare rock, making them a pioneer species. Fun fact, you can use lichen to determine if the air quality in an ecosystem is polluted.

Hope this helped :)