In gymnosperms the cone is the female reproductive part and the pollen is the male reproductive part. Pine trees and other gymnosperms produce two types of cones. The male cone is called the pollen cone. ... A single tree usually produces both pollen and seed cones.
A dichotomous key is created by scientist to identify objects and organisms.
Questions from a dichotomous key would be:
The fish have 1 eye or 2 eyes
Or if the alien have 2 heads or 1 head.
<span>The placenta is the organ which supplies an infant with oxygen, nutrients, and waste excretion throughout its gestation period; this is accomplished via the umbilical cord, which serves as a conduit between the infant, at its navel, and the placenta itself, which is attached to the mother's uterine wall.</span>
Answer:
a. the virus must be able to cross-link red blood cells directly.
Explanation:
Viral hemagglutination assay is a method which is used for the quantification of the relative concentration of the viruses.
The principle on which the hemagglutination assay works is as follows:
- There are sialic acid receptors present on the surface of the red blood cells which will bind to the haemagglutinin glycoprotein present on the surface of the viral particle.
- Due to the binding of the sialic acid receptors with haemagglutinin particle there will be cross-linking of the red blood cells by the viral particles and a lattice formation will take place.
- The lattice will remain suspended in the solution however if the concentration of the virus particles will be less, the lattice will settle down in the well.
Thus, this method allows knowing the relative concentration of the virus.
<em>Due to its basic principle of cross-linking this method works well for only a few viruses such as influenza virus. </em>
Answer and explanation:
If a human blood cell with a 0.9% solute concentration were to be put into a container of 0% solute solution, the cell would get BIGGER.
<u>The cell contains a </u><u>more concentrated solution</u><u> than the solution in the container</u>. The difference in concentration would produce an <em>osmotic gradient</em> that would cause water from the container to get inside the cell to even the concentrations - this is going to make the cell much bigger because the entering water would bloat the cell.
In this example, the solution in the container is hypotonic in relation to the cell, while the solution inside the cell is hypertonic in relation to the solution in the container. This is why the water will be moving from outside of the cell to the inside of the cell.
