Answer:
2) disruptive selection
Explanation:
Disruptive selection is a type of natural selection that acts against less fit heterozygotes. The disruptive selection can be represented by a decrease in the variance of a trait. In this case, the disruptive selection eliminates the medium-sized beaks, thereby favoring the extreme phenotypes in an interbreeding population.
Answer:
Following statements are correct
A graded potential has a threshold Graded potential amplitudes decay over distances
Graded potentials can summate in space and time
Graded potential amplitude increases with stimulus strength
Explanation:
Graded potential is generated in a neuron when ions enter or exit through the ligand gated channels. In general, this potential decreases with time before reaching axon. Signals that reach the graded potential, determine whether the amplitude of the potential will reach the threshold and hence causes action potential. Graded potential travel only over a short distance and is either depolarization or hyperpolarization. Their strength reduces with time as the charged ions move out of the membrane. They summate temporally or spatially
Graded potentials spread by passive means i.e spreading electronically to neighboring membrane regions.
Hence, the correct statements are
A graded potential has a threshold Graded potential amplitudes decay over distances
Graded potentials can summate in space and time
Graded potential amplitude increases with stimulus strength
Answer:
Feedback loop will fail in an ecosystem if the factors regulating the feedback mechanisms fail to function.
Explanation:
Feedback loop is the phenomena in which output is circled back in a way that it is used as input again i.e the reaction is circled back. Its a continuous process.
There are two types of feedback loops, positive and negative, one functions to reinforce and other functions to balance. Positive feedback loops enhance the outputs while negative lower the output and keeps the balance. the variables that are involved in all these processes effect each others so, by eliminating such variables or factors will cause failure of feedback loops.
Correct one should be C. Hope that helps.
B and C and bother correct :)
