Lava that hardens on the surface is called an extrusion. The rock layers below an extrusion are always older than the extrusion. ... There, the magma cools and hardens into a mass of igneous rock called an intrusion. An intrusion is always younger than the rock layers around and beneath it.
both P waves and S waves can travell through solids.In advance, P waves can travel through gasses too but S waves can't.
Answer:
B. Case-Control
Explanation:
A case-control is a study that compares a group with an outcome of interest (cases) with a group who do not have the outcome (controls). This study aims to looks back retrospectively to compare how frequently the exposure to a risk factor is present in each group and with that to determine the relationship between that risk factor and the outcome.
So in this case, the cases are children with pervasive development disorder and the control is those without the disorders.
These studies are normally observational because no intervention is attempted.
Answer:
Explanation:
The eukaryotic genes of interest can be expressed in the prokaryotic genome or plasmid vector. The following are the steps used for the purpose of expression of eukaryotic genes in the prokaryotic genome.
1. Amplification of the target gene of interest from the eukaryotic genome by PCR or polymerase chain reaction.
2. The selection of the plasmid and digestion of the plasmid DNA with the restriction enzyme.
3. Ligation of the amplified DNA fragment and the plasmid.
4. Introduction of the ligated plasmid into the prokaryotic host organism.
