The p53 gene is a recessive tumor suppressor gene which functions as a key regulator for the cell cycle. In the event when only one p53 allele is mutated then the function of the p53 gene will persist and apoptosis (programmed cell death) will proceed if there are significant gene mutations in the cell. If two p53 alleles are mutated then the cell will not receive the signal to apoptose even with significant mutations and cancer will develop.
Acid-fast rods present in sputum typically indicates a mycobacterial infection. Mycobacteria is a type of germ, and it can manifest in different diseases, the most common is Tuberculosis. Acid-fast is namely due to the bacteria's stain retention to the staining procedure after an acid wash.
Answer:
- If they have one child, the probability that he or she will be affected is 1/4.
- If they have two children, the probability that at least one of them will be affected is 7/16.
Explanation:
A cross between two heterozygous Aa individuals will produce the followinf offspring: 1/4 AA, 2/4 Aa and 1/4 aa.
Since the disease is recessive, 1/4 of the offspring will have the <em>aa </em>genotype and 3/4 of the offspring will be unaffected.
Every time they have children new gametes were generated <u>independently</u>.
The probability of having <u>no</u> affected children both times is, according to rules of probability for independent events, 3/4 × 3/4 = 9/16 (it's the probability of having a healthy child the first time multiplied by the probability of having a healthy child the second time).
The probability of having at least one affected child is 1 - probability of no affected children = 1 - 9/16 = 7/16.
