Answer:
Ecosystem engineers are species that modify their environment in a significant manner, creating new habitats or modifying existing ones to suit their needs.
I am more of a chemistry person, but my best answer is the double-helix structure. The DNA rotate around a central point allowing it to keep a constant distance
Scientists learn about the layers deep within the Earth's crust by studying how seismic waves travel ... Usually, they use seismic waves, which are waves generated by earthquakes
FOR MORE EXPLANTION...JUST A LITTLE MORE
NOT REALLY REQUIRED BUT YOU CAN USE JUST FOR YOUR REFERENCE..
Excellent question! Scientists use waves to study the different layers of the earth. Usually, they use seismic waves, which are waves generated by earthquakes or nuclear-test explosions. The seismic waves are bent, sped up, or slowed down, or even reflected when they pass through the earth's layers. Different types of materials (liquid vs. solid, rigid vs. softer) determine the speed of the waves. Bending of the waves occurs at the layer's boundaries. So, scientists study the path and speed of these waves through the earth to decipher boundaries and the materials that make up the layers.
THATS WITH QUESTION 1
Now 2
Most active divergent plate boundaries occur between oceanic plates and exist as mid-oceanic ridges. Divergent boundaries also form volcanic islands which occur when the plates move apart to produce gaps which molten lava rises to fill.
I hoped this helped...
~♥ ashlynn
Diagram found elsewhere attached
Answer:
Clockwise from bottom
3. formation of mRNA in the nucleus
6. secretion of hormone by tissue
4. initiation of DNA replication because of a signal given by the hormone
2. synthesis of protein molecule by mRNA and tRNA
1. secretion of protein by the cell
5. binding of the hormone molecule with its receptor of the cell
Explanation:
The tissue in the top left releases a hormone. For example, a steroid hormone such as estrogen, which can impact gene expression at the level of transcription. This hormone then travels to a different cell to carry out its function. The hormone is able to enter the cell and binds receptors which recognise it. In this case, these receptors are present in the nuclear envelope. When the hormone has bound the receptor, it initiates a signalling cascade that the cell responds to.
In this case, the effect of the signal from the hormone is to initiate DNA replication. This is a common effect of hormones such as growth factors that signal the cells to proliferate.
The initiation of the signalling can also affect how genes are expressed. In this case, an mRNA is produced in the nucleus, which is created as a result of transcription. This mRNA molecule then moves to the cytoplasm, where it becomes translated into a polypeptide sequence at a ribosome, with the help from transfer RNAs (tRNAs).
This polypeptide forms a mature protein by progressive folding and potential modifications, and is released by the cell to perform its functions.