Answer:
C. 579g
Explanation:
Use the formula Density= mass/ volume, make mass the subject of the formula and substitute the given values.
19.3g/cm3 is the density of gold
30cm3 is the volume for the piece of gold
Calcium which is a major mineral in the body
A sperm and an egg cell are each gametes. They fuse to become a zygote cell which develops into a fetus
I can’t answer how lichens arrive in a barren landscape but I can answer the 2nd part
Lichens grow when exposed to water. When wet, lichens begin to photosynthesize.
In the block to polyspermy, entry of the sperm's contents causes calcium ion levels in the oocyte's cytoplasm to rise, triggering the cortical reaction.
In biology, polyspermy describes the fertilization of an egg by more than one sperm. Diploid organisms normally contain two copies of each chromosome, one from each parent.
The cell resulting from polyspermy, on the other hand, contains three or more copies of each chromosome—one from the egg and one each from multiple sperm. Usually, the result is an unviable zygote. This may occur because sperm are too efficient at reaching and fertilizing eggs due to the selective pressures of sperm competition.
The cortical reaction is a calcium-dependent exocytotic process in which the content of secretory granules is released into the perivitellin space immediately after fertilization, which serves to prevent polyspermic fertilization.
Learn more about polyspermy here : brainly.com/question/4537960
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