Natural populations fluctuate through time. One of the forces causing variation in population size is variation in the physical environment, which can have both direct and indirect effects on populations. Variation in population size linked to environmental factors (aside from those that occur daily or seasonally) is likely to:

A) be predictable and constant.
B) be density-dependent.
C) affect the biotic potential exponentially.
D) be irregular, perhaps even random.
E) track the logistic growth model.

Interpret the model. a three-part model with black right-arrows between the parts. left part: a large green apple-shaped component with a w-shaped indentation centered on top. a small blue apple-slice shape sits above the left indentation and an arrow points from the shape to the indentation. a small purple apple-slice shape and arrow sit above the right indentation and an arrow points from the shape to the indentation. middle part: a large green apple-shaped component with a square indentation centered on top. sitting in the left side of the indentation is a blue apple-slice shape with a flat bottom, fused to a purple apple-slice shape with a flat bottom on the right side of the indentation. right part: a large green apple-shaped component with a w-shaped indentation centered on top. an up-arrow is centered above the indentation pointing to a fused blue and purple apple-slice-shaped flat-bottom component sitting above the indentation. assigne "true" or "false" to the end of each statement. the model shows a shape change occurring in the enzyme after the substrate is bound in the active site. t/fthere are two products in this model. t? f there are three substrates in this model. t/f the model shows two different enzymes. t/f

Which of the following scenarios is an example of the bottleneck effect? answers a in south africa, much of the afrikaner population is descended from a small number of dutch colonists. in this population, this is an unusually high frequency of pseudoxanthoma elasticum (pxe), an elastic tissue disorder. b four white-tailed deer are introduced to a park in finland. thirty years after their introduction scientists compare the genes in the population and find that there is no variation. c during the industrial revolution, london's air became filled with soot. as a result, birds started eating more of the lighter moths because they were easier to spot than their darker counterparts. over time, the moth population changed so that there were more darker moths than lighter ones. d 10% of the population of american alligators in an area have the recessive trait albinism. a massive flood results in the death of 80% of the population. of the remaining population, 60% have the recessive trait of albinism.

Deer cave cannot support photosynthesis is as not enough sunlight is present. in spite of this, it still has a complex food chain. what is the energy foundation of this food chain?