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What penetrates an egg?
During fertilization, enzymes at the tip of the head of the sperm help penetrate it.
After puberty, how many and how often are eggs produced?
Only one is produced and about every month.
what was amino acids gathered into , which was the first step to cellular organization?
why are fossils often used as evidence of evolution?
it shows how organisms change with he passage of time.
A sexually transmitted disease can be treated and cured with antibiotics if they are what?
caused by Bacteria
Why was ozone imprtant in enabling organisms to live on land?
It protects us from ultraviolet radiation.
What is the Endosymbiotic theory?
the theory that proposes how eukaryotic cells arose from prokaryotic cells. mitochondria and chloroplasts was thought to be prokaryotic cells at one time.
Larger prokaryotic cells engulfed mitochondria and chlroplasts and the formed mutualistic relationship resulting in out first eukaryotic cells.
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