Answer:
The earth’s crust is broken into separate pieces called tectonic plates (Fig. 7.14). Recall that the crust is the solid, rocky, outer shell of the planet. It is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. Both types of crust rest atop solid, upper mantle material. The upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.
Each tectonic plate is free-floating and can move independently. Earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. The term fault is used to describe the boundary between tectonic plates. Most of the earthquakes and volcanoes around the Pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. Other observable results of short-term plate movement include the gradual widening of the Great Rift lakes in eastern Africa and the rising of the Himalayan Mountain range. The motion of plates can be described in four general patterns:
<p><strong>Fig 7.15.</strong> Diagram of the motion of plates</p>
Collision: when two continental plates are shoved together
Subduction: when one plate plunges beneath another (Fig. 7.15)
Spreading: when two plates are pushed apart (Fig. 7.15)
Transform faulting: when two plates slide past each othe
Explanation:
Answer:
Natural selection leads to evolution due to the way reproduction works. In the example of European moths during the industrial revolution, we can see this clearly. When the industrial revolution was going, there was more pollution, hence darkening the skies and leaving ash. Moths, which before were white with occasional black spots dominated the area until pollution effected their environment. Whiter moths were eaten by bird who could easily see them against the black trees and skies. These moths could no longer reproduce, they were dead. Moths with more black could survive longer to reproduce because they were harder to see. As time went along, the moths turned mostly black, showing an example of evolution.
The correct answers are:
- Methylation of histone tails in chromatin can promote condensation of the chromatin.
- DNA is not transcribed when chromatin is packaged tightly in a condensed form.
- Acetylation of histone tails is a reversible process.
- Some forms of chromatin modification can be passed on to future generations of cells.
- Acetylation of histone tails in chromatin allows access to DNA for transcription.
Histone modifications are post-translational modifications of histone protein that can affect gene expression by altering chromatin structure or recruiting histone modifiers.The most common modifications are methylation, phosphorylation, acetylation and ubiquitylation. All of them affect the binding affinity between histones and DNA and thus loosening (gene activation) or tightening (gene repression) the condensed DNA.
Histone methylation is a transfer of methyl group by histone methyltransferases to lysine or arginine amino acid of protein. Effect of methylation depends on the type of protein that is modified. Demethylation is the reverse process.
Histone acetylation is the process of adding of an acetyl group(by histone acetyltransferases) to histone proteins and it can also activate or inhibit the gene expression. Deacetilation is reverse process.
Answer:
Interesting assignment. I really hope this helps! -
Explanation:
You are going to use the chart where he graphed the data on his hamster's diet to dissect and identify, the parts of this scientific method.
TIP - try to think of this in a first-person perspective meaning try to think of this as you doing the experiment.
Hope this helped understand this assignment. :)
One affect could be a loss of habitat for the animals that lived in that forest