Ventilation systems are needed in a <span>multicellular organism to actually obtain oxygen and give out carbon dioxide. Without this ventilation system, it would be very difficult for multicellular organisms to survive. It has been also observed that surface diffusion is not enough for a multicellular organism to breath.</span>
Answer:
50% or 1/2. The result remains unchanged if the husband were to have G6PD.
Explanation:
For X-linked recessive inheritance, a female (XX) needs two recessive alleles to be affected while a male needs only one (XY). It is hypothetically assumed that the Y chromosome does not carry any trait.
Assuming the allele for the disease is represented by g, a woman whose father suffered from G6PD is a carrier for the disease with genotype 
. A normal man will have the genotype 
. When the 2 marries:
x = 
It thus means that 50% or 1/2 of their sons will be expected to have G6PD.
Now, assuming the husband has G6PD, the mating becomes:
x 
= 
50% or 1/2 of their sons is still expected to have G6PD. The ratio remains unchanged.
Answer:
Mantle plumes that form hotspots are thought to be relatively stationary whereas the overlying tectonic plates typically are not. Thus, as a plate moves over the location of a plume eruption, it carries successively older volcanoes with it.
There should be options for this question. I manged to find them elsewhere. They are:
A) the period during which tremendous growth occurs and the organs continue to develop and become functional
B) the period during which the umbilical cord develops
C) the period during which the major organs and structures of the organism first develop
D) the period during which the zygote moves down to the uterus and begins to implant in the lining
The correct answer is C. The embryonic period is the period during which the major organs and structures of the organism first develop. The embryonic period lasts from implantation of the egg in the uterus until about 8 weeks from the time of conception. It is the second major stage of prenatal development, prior to embryonic is the germinal stage and lastly is the fetal stage.
