Answer:
The short term effects of stress include pain, nausea, change in appetite, heartburn, constipation, and in some cases, diarrhea.
Long term effect of stress on the body and behavior include changes in one's eating habits and chronic pain. Another long-term effect of stress is acid flux.
Asides having negative effect on the body and behavior, stress can also have some negative effect on the brain such as increasing the risk of developing mental illness, killing of the cells in the brain, brain shrink, and it can hurt one's memory.
Explanation:
We'll make the alleles: Cc.
C is a healthy parent, and c is the cystic fibrosis (recessive).
If you make a punnett square and the parents are both Cc (healthy), then you would get CC, Cc, Cc, and cc. That cc is a 25% chance that the offspring will have that, which means there is a 25% chance the child will have cystic fibrosis.
Two healthy parents can have a child with cystic fibrosis if both the parents have the dominant allele and recessive allele, if both the parents have heterozygous alleles.
<span>My pea plant has an unknown genotype for flowers, whether it has two dominant traits for white flowers (WW) or one dominant and one recessive (Ww) leading to white flowers; therefore I am doing a testcross in order to determine the genotype of my pea plant. The best plant to do this with is one that has a phenotype of purple flowers (ww) - that is, it is homozygous for the recessive trait.
If I use a homozygous recessive plant, I know exactly what its genotype is. I don't have to worry about whether it's got one or two dominant alleles; I know that at least half of my alleles are going to be the recessive w.
This makes identifying the offspring's genotype very simple. If I find that the offspring have at least some purple flowers among them, I know that my original plant had to be Ww; that is it had to have one dominant and one recessive allele for the flower color gene. If, however, all of the offspring are white flowers, I know that my original pea plant had both dominant alleles (WW).</span>
"Viruses straddle the definition of life. They lie somewhere between supra molecular complexes and very simple biological entities. Viruses contain some of the structures and exhibit some of the activities that are common to organic life, but they are missing many of the others. In general, viruses are entirely composed of a single strand of genetic information encased within a protein capsule. Viruses lack most of the internal structure and machinery which characterize 'life', including the biosynthetic machinery that is necessary for reproduction. In order for a virus to replicate it must infect a suitable host cell".
From The Bacteriophage T4 Virus
