The model describes how cellular membranes i.e. lipid bilayers are organized. Despite the fluidity, lipid bilayers can form certain domains with different characterisrics and compositions. The cell can use different mixtures of lipids to create a 'mosaic' or 'patchwork' of domains.
An example of such domains are so called 'lipid rafts' which are aggregates of certain lipids (mostly cholesterol and sphingomyelins). In these rafts the lateral diffusion of membrane-bound proteins is strongly reduced, thereby forming stable complexes to facilitate, for example, signal-processing and transduction.
Note that a lot about how or why a cell creates these domains is still unknown.
Answer:
Anomalous expansion
Explanation:
Anomalous expansion of water is the abnormal way water expands when exposed to low temperature.
At 4 degree Celsius , the density at the top layer is usually at the Maximum which makes the water sinks down and then the water in the lower layer rises up.
When the temperature drops below 4 degree Celsius, the water molecules at the top then freezes leaving the denser molecules at the bottom which doesn’t freeze as a result of their high density.
This way, organisms can survive in the water due to the lower layer not freezing.
Answer:
a. a portion of the population becomes isolated from the remainder of the population and experiences different selective pressures
Explanation:
This is an example of allopatric speciation Allopatric speciation is a form of speciation (formation of new species) that occurs as a result of geographic isolation. This means that a part of population becomes physically separated from the initial main population. There is no gene flow between these two populations and as a result the two populations reach a high level of genetic divergence. They can no longer interbreed which means they become two different species (speciation).
New populations evolve as result of mutation, genetic drift and natural selection.
For example, Galapagos finches are isolated from others by the ocean (geographic isolation). Because of the isolation, the finches don’t breed with one another. So, they developed unique characteristics and became endemic.
True, a vast, flat, treeless Arctic region of Europe, Asia, and North America in which the subsoil is permanently frozen.
