Based on what they knew about the fertilization envelope (a protective layer that forms around the egg when a sperm fuses with it), steinhardt, shatten, and their colleagues hypothesized that changes in the distribution of ca2+ ions in sea urchin eggs are involved in the formation of the fertilization envelope. in sea urchin eggs (as in most eukaryotic cells) the concentration of ca2+ ions is much higher in the endoplasmic reticulum (er) than in the cytoplasm. to see how cytoplasmic ca2+ concentration changes in the egg during fertilization, the researchers injected a ca2+-specific fluorescent dye into the cytoplasm of unfertilized eggs. after adding sperm to the eggs, they observed the eggs with a fluorescence microscope. the following images show the changes in fluorescence that occurred after a single sperm entered the egg. the fluorescence of the dye increased with increasing cytoplasmic ca2+ concentration. the green color indicates the region of the cell with the highest fluorescence at that point in time.

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.

name and explain one of the event that occurs during meiosis that increases the variation in offspring even more than simple reproduction?

a researcher conducts an experiment on the secretion of a particular hormone in mice. scientists inject mice with a substance that stimulates the production of the hormone. the scientists then test the levels of hormones produced by the mice. the tool used to measure the hormones consistently detects the levels at 10 points lower than the actual hormone levels in the mice. this tool makes measurements, but the measurements aren't .

explanation:

no u

i think its white blood cells

i hope this