You and I are different genetically because of the different nucleotides in our DNA.
If the first child born to a couple heterozygous for freckles, does have freckles, the chances of their second child having freckles is 25%.
Because of meiosis, a gamete has one allele for each gene.
If freckles are controlled by a dominant allele, F, individuals who are either homozygous dominant or heterozygous will have freckles.
If two individuals whose genotypes are both heterozygous for freckles mate, the chance of their child having freckles is 75%.
Pattern of inheritance in which a trait is controlled by several allele pairs.
Allele controlling a trait is located on an X chromosome even though it has nothing to do with sexual characteristics.
sex linked inheritance
Inheritance pattern in which there are more than two possible alleles for a particular trait, though each individual only has two of the many possible alleles.
Inheritance pattern in which the offspring has a phenotype like neither parent but intermediate to the phenotypes of the parent.
An individual expressing a dominant phenotype has only one possible genotype.
ABO blood types
red-green color blindness
Autosomal recessive inheritance
autosomal recessive inheritance
A DNA molecule resembles a twisted ladder in which the rungs of the ladder are complementary base pairs of Adenine paired with Thymine and Cytosine paired with Guanine.
Gene therapy has not, as of yet, been successful in human trials.
Transgenic bacteria are used today in the cleanup of oil spills, in the production of t-PA to treat heart attacks, and in the production of injectible insulin..
RNA is a double stranded helix.
Bacteria, plants and animals that have been genetically altered by the insertion of foreign genes are called mutant organisms.
Current ex vivo and in vivo gene therapy clinical trials may use a virus as a vector to insert healthy genes into patient's cells.
The Human Genome Project has described the order of the 3 billion bases in the human genome.
Transcription is the cellular process whereby information contained in the nucleotide sequesnce of RNA is converted into a sequence of amnio acids.
Products to treat human disease can be made in bacteria and animals but not in plant cells.
Gene cloning is the production of genetically identical copies of DNA.
When an individual reaches the AIDS phase of HIV infection there is then a short life expectancy without successful treatment. What occurs in the AIDS phase to shorten life?
The immune system is compromised leaving the individual at high risk for pneumonia, cancer, and other life-threatening illnesses.
What is the BIOLOGICAL explanation for the elderly being at greater risk for becoming dehydrated than a younger person having the same fluid intake?
The kidneys are smaller and less efficient at filtering.
The two most common means of HIV transmission in the U.S. is sexual activity and IV drug use.
What is the BIOLOGICAL explanation for the increased incidence of high blood pressure in the elderly?
The elastic fibers in the artery walls become cross-linked making the arteries more ridgid.
What is the BIOLOGICAL explanation for the observation that we often struggle more with weight gain as wer age than when we were younger?
The elderly have a decreased basal metabolism.
In which phase of HIV infection is the infected individual likely to be asymptomic but highly infectious?
Which of these is LEAST likely to be a possible route of HIV transmission in the U.S.?
List common symptoms of the chronic phase of HIV infection.
swollen lymph nodes, severe fatigue, unexplained persistent or recurrent fevers, night sweats persistent cough, persistent diarrhea, inability to think clearly, loss of judgement, loss of memory, depression
What is the BIOLOGICAL explanation for an increased incidence of cancer and autoimmune disease in the elderly?
There is a decline in the immune function including a decrease in the size of the thymus gland.
What is the BIOLOGICAL explanation for the elderly often requiring lower doses of medications than younger individuals?
There is a reduced blood flow to the liver so drugs are metabolized more slowly.
Which of the following accurately describes changes in blood tests seen in the AIDS phase of HIV infection?
high HIV count, low CD4 T lymphocyte count
What is the BIOLOGICAL explanation for the observation that the elderly often have increased sensitivitiy to cold?
There is a loss of insulating fat in the subcutaneous layer of the skin.
What is the BIOLOGICAL explanation for the elderly being at greater risk of broken bones?
There is a loss of bone density as we age as a result of calcium depletion (osteoporosis).