Thermocline - <span>a steep temperature gradient in a body of water, that is marked by a layer above and below at which the water is at different temperatures.
halocline - </span><span> a subtype of chemocline caused by a strong, vertical salinity gradient within a body of water.
pycnocline - </span><span>a layer in an ocean or other body of water in which water density increases rapidly with depth.</span>
Answer:
B
Explanation:Im on brainpop too and it says the answer is b
In prophase 1:
Chromosomes become visible, crossing-over occurs, the nucleolus disappears, the meiotic spindle forms, and the nuclear envelope disappears.
In metaphase 1:
The pairs of chromosomes (bivalents) become arranged on the metaphase plate and are attached to the now fully formed meiotic spindle. The centrioles are at opposite poles of the cell.
Heart,vessels,circulating fluids