A reproductive difference between sea urchins and humans is
A) the sea urchin egg completes meiosis prior to fertilization, but meiosis in humans is completed after fertilization.
B) sea urchin eggs are produced by meiosis, but human eggs are produced by mitosis.
C) sea urchin eggs and sperm are of equal size, but human eggs are much bigger than human sperm.
D) 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 fertilize the eggs.
E) sea urchin zygotes get their mitochondria from the sperm but human zygotes get their mitochondria from the egg.
Difference between Asian (left) and African (right) elephant ears.
The thorax of apes, including humans, is broad but shallow in contrast to the narrower, deeper chest
The Male Reproductive System
Female Reproductive System "الجهاز التناسلي للأنثى"
Independent assortment for two traits in humans follows the same pattern of inheritance as traits in
Curved spines make cocklebur (Xanthium) fruits stick to the fur of animals (and clothing of humans)