The answer is pronuclei. A pronuclei is the state of the
nucleus of either the sperm or the ovum after the sperm has entered the ovum
but the two nuclei have not yet fused. When the sperm enters the ovum, the membrane
of the sperm pronuclei dissolves hence leaving no barrier for the two genetic
materials to combine.
Jellyfish, Komodo dragon, & bacterium
The KT boundary marks a mass extinction event. the KT boundary is the time between the Cretaceous and Tertiary periods. An asteroid hit the earth at the end of the Cretaceous and that caused the end of the Cretaceous period. Before the KT boundary, pollen from angiosperms and gymnosperms is high. After the meteor hits the earth, a mass extinction occurs and the amount of pollen from gymnosperms and angiosperms decreases dramatically, while the amount of spores from ferns increases. During the Cretaceous period there were many species of gymnosperms and angiosperms but they disappeared at the KT boundary, when the asteroid hit the earth.
Explanation:
The length of the sperm in a few species is much larger or giant than the size of the animal-like observed in the <em>Drosophila bifurca.
</em>
In this fruit-fly, the tails of the sperm are too long which could be accounted for many reasons:
1. The sexual selection prefers the long tails over the small tail.
2. The large sperms can displace the small sperms in the female reproductive organ.
3. The female reproductive organ increases the promiscuity of the large sperms that is favour the large sperms over the small sperms.