Suppose an experiment was conducted where all of the rabbits were removed from a meadow. Which of the following results is least likely to be observed?

(1) The predator population, such as hawks, would decrease.
(2) The grasses and shrubs would grow taller and fuller.
(3) Flea and tick populations would increase.
(4) Other small herbivore populations would increase.

Option 1 and 2 are correct

Explanation:

In a given ecosystem rabbits serve as prey for several predators. The growth of predator population is depended on the population of rabbits. The higher the population of prey, the higher is the population of predator.  

Thus, if the population of rabbit is decreasing, then the population of predator such as hawks will decrease.  

Since the rabbits eat grasses and shrubs, thus in their absence the productivity of grasses and shrubs will also increase.

Option 1 and 2 are correct

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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