One of the negative impacts of eutrophication and increased algal growth is a Loss of oxygen known as anoxia
1. The cell wall has lignin (hard substance): to prevent the xylem vessel from collapsing and withstand high pressure.
2. The absence of protoplasm (nucleus + cytoplasm) and cross wall: to allow water to move through the lumen easily.
Hope it helped!
<span>Metamorphic rocks form by existing rocks join together under high heat and pressure. Examples of metamorphic rocks are marble, schist, slate, and quartzite. Metamorphic rocks formed when the minerals are chemically changed due to heat and pressure. They are often seen near magma but they do not melt like igneous rock.</span>
As any other ancient civilization, the Sumerians were traders as well. And they had a few good reasons to do this.
Because they traded, their trading partners were less likely to attack them, because it would hurt their economy as well. Furthermore, they didn't produce everything they needed and traded those goods with goods which they produced too much of.
And lastly, through trade they could also get exotic goods which they would have never gotten otherwise.
