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Dec 28, 2020 · Distinguish between primary and opportunistic pathogens and identify specific examples of each. Summarize the stages of pathogenesis. Explain the roles of portals of entry and exit in the transmission of disease and identify specific examples of these portals.
Communicable diseases - AQA. Pathogens are disease-causing viruses, bacteria, fungi or protists, which can infect animals and plants. Humans have an immune system, which can defend them from ...
Apr 23, 2022 · Diffusion is a type of transportation that occurs across the cell membrane. It can be defined as: The net movement, as a result of the random motion of its molecules or ions, of a substance from a region of its higher concentration to a region of its lower concentration.
- The Externalism of Evolutionary Biology
- Problems For Evolutionary Biology
- Problems For Adjacent Disciplines
- The Reciprocal Causation Revision
Godfrey-Smith (1996) describes evolutionary biology as ‘externalist’, by which he means that the adaptations of organisms are described relative to the characteristics of external environments. Mayr’s position, which exemplifies that of the Modern Synthesis, was ‘externalist’ by assuming that the selective environments of organisms pre-exist the bi...
The primary problem derived from the externalist stance, reinforced by the proximate-ultimate causation dichotomy, for evolutionary biology itself is that it has hindered the full recognition of the pathways by which organisms’ ontogenetic processes affect evolutionary processes. Two points that we have already made are that the modern synthetic th...
Developmental biology
The longstanding tension between developmental and evolutionary biology in part reflects evolutionary biologists’ treatment of development as a ‘black box’ (e.g. Mayr 1980; Maynard-Smith 1982), which precludes any causal role for the organism in constructing both selective environments and variants subject to selection (Amundson 2005): We have already noted that black-boxing masks developmental bias. Mayr’s view of development as an unfolding of information encoded in the genome is equally pr...
Ecology
Ecology is a divided discipline, with separate (evolution-embracing) population/community and (evolution-ignoring) ecosystem approaches, in part because contemporary evolutionary biology does not provide tools to capture the ways organisms engineer habitat, control and regulate flows of energy and matter, and drive state changes in abiota (O’Neill et al. 1986; Odling-Smee et al. 2003). Many ecologists recognize an inherent problem in integrating their discipline: These divisions can be seen t...
Behavioural ecology
In their core textbook, Davies et al. (2012, p. 22) state ‘Behavioural ecology aims to understand how behaviour evolves in relation to ecological conditions’. It is perhaps surprising, then, that fellow behaviour ecologist Deborah Gordon (2011a) should complain that the fields of behavioural ecology and ecology are not well-integrated. This claim is striking given that many behavioural ecologists dedicate much effort to collecting ecological data but, as noted above, the links of evolution (o...
Given that we believe that the proximate-ultimate dichotomy has both scientific limitations (it constrains understanding evolutionary change) and social problems (it reduces communication between researchers of different background), what do we offer as an alternative? The conceptual revisions necessary to fully integrate evolutionary biology with ...
- Kevin N. Laland, John Odling-Smee, William Hoppitt, Tobias Uller
- 2013
Aug 29, 2024 · Examples of substances that leave cells by diffusion: Liver cells break down excess amino acids into the waste product urea which is highly toxic and must diffuse out of cells to be excreted by the kidneys. Carbon dioxide produced by aerobic respiration must diffuse out of cells.
12 examples of competition relationships. Competition is a common phenomenon in nature, where different species compete for the same limited resources in their environment. These resources can be anything that is essential for survival, such as food, water, sunlight, space, or shelter. 1. Lions vs. hyenas.
Examples. Let's look at a couple of examples of explaining a trait or behavior using Tinbergen's four questions: Visual perception. Function: to find food and avoid danger. Phylogeny: the vertebrate eye initially developed with a blind spot, but the lack of adaptive intermediate forms prevented the loss of the blind spot.
