Answer:
A). Dividing the number of organisms in a region by the land area.
Explanation:
The formula for calculating population density PLUS example:
Photosynthesis allows autotrophs to make their own food, then in turn heterotrophs eat the autotrophs giving them food. It's like a big cycle!
Answer:
The neurons interact with each other at synapse through action potential generated in response to the stimulus. At the resting phase, all the ion channels remain closed and the cell maintains a high amount of Na⁺ ions outside the cell and a high amount of K⁺ ions inside the cell. This difference maintains the membrane potential at -70mv.
When a stimulus activates a cell receptor, it causes the opening of the sodium channels in response to either mechanical stimulus or neurotransmitter released due to stimulus. The opening of the sodium channels leads to the influx of Na⁺ ions which changes the potential from -70 mv to more positive value. When this change in membrane potential reaches - 55 mv it leads to the opening of the voltage-gated channels which causes an influx of Na⁺ ions. This more influx of Na⁺ ions leads to depolarization when the membrane reaches above the threshold and the action potential is generated in the neuron.
23. centromeres
25. mitosis
27. cancer
29. sister chromatid
31. tissues
