Answer:
When we observe the position of a star its position changes over the course of a year. It will return to the same position a year after the first measurement. This effectively proves that the Earth is in orbit.
Answer: Option 4.
The fresh water is hypotonic and the salt solution is Hypertonic.
Explanation:
Hypotonic solution is a solution that have little dissolved solutes i.e low osmotic pressure compare to other solution. When a cell is put in hypotonic solution, it take in water and the cell swell up and it does not burst due to it's cell wall thereby becoming turgid or hard.
Hypertonic solution is the solution where the concentration of solute is higher outside the cell than inside the cell. Example is saline water.when a cell is placed in Hypertonic solution it will shrinks because it losses water.
Answer:
Change in the species structure of an ecological community over time. (A)
Explanation: Google
Well, contour lines are used to signify a three-dimensional image of a flat surfaces. They are commonly used on topographic maps. Here contour lines connect continuous points of equal elevation. There is a connection between the change of height and the relative change of distance. If you move from one contour line to another then there is a change of height. The closer the lines are the 'faster' the height changes, and thus the 'steeper' the terrain. The further apart the contour lines are, the greater distance over which height changes, the slope is gentler.
