Answer:
In biology, adaptationism is the perspective that considers that the majority of traits are optimal adaptations achieved by natural selection.
Explanation:
Among his most famous defenders are John Maynard Smith, W.D. Hamilton, Richard Dawkins and Daniel Dennett. Adaptationism has been criticized by authors such as Stephen Jay Gould and Richard Lewontin.
Stephen J. Gould summarizes the "adaptationist program" in the following arguments:
- Adaptation is the central phenomenon of evolution, and the key to understanding its mechanisms.
- Natural selection builds adaptation.
- Natural selection maintains an overwhelmingly predominant relative frequency as a cause of adaptation. Variation only provides raw material and cannot do the job without help.
<u>Characteristics of adaptationism
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Gould and Lewontin (1979) summarize the following way of proceeding from the adaptationist program:
- Atomization of the organism: division of the organism into discrete and disconnected features.
- Optimization of the parts by natural selection.
- Explanation of the adaptations.
Answer:
B) You measure the quantity of the appropriate pre-mRNA in various cell types and find they are all the same.
Explanation:
In the above scenario, we are using the control gene and we should know about the control gene is that its expression is either at transcription level or at translation level. For this situation we should examine the pre-mRNA stage of control gene in various cells because it is control gene so it should be present in various cells.
So, the best practice is to quantify the pre-mRNA level of gene then we can effectively solve the experimental problem and find the gene expression either it is at transcription or translation level.
Answer:
Abstract
Respiratory homeostasis is concerned with the regulation of a blood gas composition that is compatible with maintaining cellular homeostasis. Provided that the lung-capillary exchange barrier does not prevent the exchange of gases, then blood leaving the lung will have oxygen and carbon dioxide partial pressures that are similar to the average values found in the alveoli. Alveolar ventilation establishes these values. If blood gas composition, especially of carbon dioxide, moves outside the homeostatic range, the change is detected by chemoreceptors and respiratory responses are promoted which change alveolar ventilation, alter alveolar gas composition and so reverse the change. Ventilation therapies provide the means of artificially restoring alveolar gas composition. In general terms, they do this by raising the partial pressure of oxygen within the alveoli either by using oxygen-enriched gas mixtures, or by improving the ventilation of alveoli using positive pressure.
Explanation: