Leeches are parasitic because they suck blood not giving any benifit but harm.
Answer:the first one I believe!
Explanation:
Sorry if it is wrong I have already done this and I pretty sure it’s the first one!
The mechanisms of reproductive isolation prevent the reproduction of two individuals from different species. The prezygotic mechanisms disrupt the stages of reproduction before the forming of the zygote or prevent the mating at the start, and the postzygotic mechanisms affect the stages of reproduction after the forming of the zygote.
So, the first and the third example (the urchins and the grasshoppers) show the prezygotic mechanism, as the two individuals are not able to mate or form a zygote.
The second and the fourth example ( zonkey and the death of a zygote) show the working of the postzygotic mechanisms, as the zygote is formed, but it seems to be inviable, and the zonkeys are sterile, preventing the individual to reproduce.
Answer:
Dehydration
Explanation:
What causes bacteria to die in an extremely salty environment is dehydration due to the loss of osmotic balance in their cells.
Water molecules would normally move from the region of high water potential or low solute concentration to the region of low water potential or high solute concentration through a biologically permeable membrane.
<em>An extremely salty environment would be hypertonic to the cells of bacteria and the cell walls of bacteria act as biologically permeable membranes. Hence, the bacteria cells lose water due to the osmotic movement of water from their cells to the surrounding salty environment. </em>