The major agent responsible for erosion on the Earth's surface is water. Flowing water as a result of rain, melting glaciers, moving streams and rivers erodes surfaces by displacing bits of soil and rocks, which is then moved from its original location to another.
Answer:
Macroevolutionists cannot make direct observations because most of the organisms are dead or extinct.
Explanation:
only true one
Answer:
a. two sperm enter the ovule; one fertilizes the egg, one fuses with 2 polar nuclei
Explanation:
Double fertilization is the characteristic feature of the angiospermic plants. After pollination, pollen grains deposited on the stigma of the pistil or carpel. The pollen grain on the stigma germinates forming a pollen tube. The pollen tube carrying two male gametes grows down through the style of the pistil and enters into the embryosac formed within the ovule and releases two male gametes.
One of the gametes fuses or fertilizes with the egg forming zygote. The other male gamete fuses with the two polar nuclei of the embryo sac. The fertilization between two polar nuclei and one male gamete is called the triple fusion. The triple fusion results in triploid primary endosperm cell (3n).
Thus, in angiosperms, there are two fertilizations called double fertilization resulting in the zygote (2n) and primary endosperm cell (3n).
Answer:
A
Explanation:
The Answer is A.
Some people consider peat to be non-renewable because it accumulates very slowly – a millimeter a year.