Gravity , Explosion
<u>Explanation:</u>
Nebulae are made of dust and gases—mostly hydrogen and helium. The dust and gases in a nebula are very spread out, but gravity can slowly begin to pull together clumps of dust and gas. As these clumps get bigger and bigger, their gravity gets stronger and stronger.
Eventually, the clump of dust and gas gets so big that it collapses from its own gravity. The collapse causes the material at the center of the cloud to heat up-and this hot core is the beginning of a star.
Answer: sexually reproducing organisms
Explanation: In most sexually reproducing organisms, each adult has two copies of each gene--one from each parent. These genes segregate from each other when gametes are formed. Alleles for different genes usually segregate independently of each other.
The anthers are in the elevated position so that the pollinators will be attracted towards it, and that the pollen grains are easily carried away by the agents of pollination. The proper pollination is essential for the process of fertilization.
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