Multiple Choice
A reproductive difference between sea urchins and humans is ________.
A) the sea urchin egg completes meiosis prior to fertilisation, but meiosis in humans is completed after fertilisation
B) sea urchin eggs and sperm are of equal size, but human eggs are much bigger than human sperm
C) sea urchins, but not humans, have a need to block polyspermy, because only in sea urchins can there be more than one source of sperm to fertilise the eggs
D) sea urchin zygotes get their mitochondria from the sperm, but human zygotes get their mitochondria from the egg
Correct Answer:

Verified
Correct Answer:
Verified
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