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: "photosynthesis" .
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<u>Note</u>: These small, moving "green disks" seen while observing an <em>Elodea</em> plant cell—under a microscrope— are "chloroplasts". The "chloroplasts" are organelles that ar responsible for "photosynthesis" .
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Complete question:
Question: When crossing two individuals, the offspring display only one of the two traits found in parents. Which principle of Mendelian genetics is supported by this observation?
a) segregation
b) independent assortment
c) dominance and recessiveness
d) allele frequency
Answer:
c) dominance and recessiveness
Explanation:
According to Mendel's principle of dominance and recessiveness, the alleles of one gene may be dominant or recessive in nature. When present together, only the dominant allele is able to express itself. Therefore, a hybrid individual for a gene would express only the dominant phenotype. In the given cross, the progeny express only one of the two traits found in the parents. This means that the progeny is heterozygous for the trait and is expressing the dominant trait. The recessive trait is not expressed due to the presence of the allele for the dominant trait.
<span>There are four basic modes of plasma transportation, these include: diffusion, osmosis, facilitated diffusion and active transport. Diffusion, osmosis and facilitated diffusion are passive transport because, their movement through the plasma membrane does not require energy while transportation through active transport requires energy.</span>
