<span>Damming a river has a variety of effects on the freshwater ecosystem, more than just altering the flow from A to B. Dams create calm bodies of water, changing overall temperature regimes and sediment transport, leading to conditions which tend to favour generalist species. Loss of specialist species, particularly endemics, changes the community structure and leads to biotic homogenization. A dam will withhold sediment in the reservoir, not just decreasing the amount of substrate available to local freshwater species, but even impacting diadromous, estuarine and marine species much further downstream. The competition between resident species for food and breeding sites will increase as damming isolates populations, and perhaps more importantly, damming completely restricts migratory fish species. Isolation may lead to decreases in genetic diversity and therefore puts species at greater risk from disease. All of these effects may be exacerbated by changes in the surrounding land use. Overall, damming river flow will lead to both a loss of native species, but also an increase in exotic species which are more likely to become established in degraded habitats. For this reason, dams are one of the greatest global threats to freshwater biodiversity.</span>
So in order to form a new organism, two gametes -- the sex cells, sperm and egg -- must fuse, further mixing the genes to produce more genetic diversity. Asexual reproduction is one organism dividing into two organisms without shuffling its genes, so the offspring has the same version of genes as did the parent.
Plants have cell walls, so cytokinesis cannot go on with a cleavage furrow, but instead, a cell plate forms across the cell in the location of the metaphase plate.
There is no distinct groove along the cell plate as the cell divides because of the rigid nature of the cell plate or new cell wall.
A plant cell divides differently from an animal cell which forms a clear cleavage furrow because it only has a flexible cell membrane and not a rigid cell wall like plants.
The cell plate in plant cells is formed by membrane bound vesicles which migrate to the center of the cell where the metaphase plate used to be and fuse together to form a cell plate.
The second type of body fluid, the extracellular fluid, have two types: the interstitial fluid and the intravascular fluid. The interstitial fluid serves as a messenger for transferring materials to and from cells. While the intravascular fluid is responsible for being within the circulatory systems of the body, being am addition of 4% of the body's weight.
The correct answer is "crossing over."
Cellular growth takes place under interphase, specifically under G1 phase of interphase wherein there is increase in cell proteins and structure. Duplication of chromosomes (or DNA synthesis) takes place under interphase, specifically under the S phase of interphase. In the S phase, there is also duplication of organelles. Crossing over takes place under prophase I of meiosis.
