Two major sources of mutation are radiation and reactive oxygen species (ROS).The reactive oxygen species hypothesis for aging postulates that 

1) Senescence results from the accumulation of DNA, lipid, and protein damage inflicted by ROS of mitochondrial origin; and

2) Mitochondria of long-lived species should produce high ROS than do mitochondria of short-lived species.

3) the capacity of mitochondria to consume ROS might distinguish long-lived species from short-lived species, rather than differences in ROS generation. 

#Question id: 5294

#Unit 8. Inheritance Biology

Interrupted mating experiments were performed using three different Hfr strains (1-3). The three strains have different combinations of selectable markers. The time of entry for markers for each strain is shown is shown in the table given.

Using the above data, predict the correct sequence of markers on the E. coli chromosome

#Question id: 5293

#Unit 8. Inheritance Biology

The two strains a and b are tested for being auxotrophic for the following nutritional mutations: pyridoxine (pdx), biotin (bio), methionine (met), adenine (ade), and para-aminobenzoic acid (pab). Growth is indicated by ( + ) and lack of growth by ( - ). From these tests, what is genotype of strain a and b respectively (+ indicate prototroph while other auxotroph)? 

#Question id: 5292

#Unit 8. Inheritance Biology

A transformation experiment is performed with a donor strain that is resistant to four drugs: W, X, Y, and Z. The recipient is sensitive to all four drugs. The treated recipient population is divided up and plated on media containing various combinations of the drugs. The table below shows the results:

Following observation are given

A) X gene is obviously quite distant from the other three genes

B) Y gene is obviously quite distant from the other three genes

C) The Order is three closely link gene W Z Y

D) The Order is three closely link gene W X Z

Which of the following combination is correct?

#Question id: 5291

#Unit 8. Inheritance Biology

A number of nutritional mutant strains were isolated from wild-type Neurospora that responded to the addition of certain supplements in the culture medium by growth ( + ) or lack of growth ( -). Given the following responses for single gene mutations, diagram a metabolic pathway that could exist in the wild-type strain that is most consistent with the data. Indicate where the pathway is blocked in each mutant strain.

#Question id: 5290

#Unit 8. Inheritance Biology

The following table shows mapping data from three interrupted mating experiments using three different Hfr strains and an F- strain: The order of genes is

#Question id: 5289

#Unit 8. Inheritance Biology

A donor strain of bacteria with genes a+b+c+ is infected with phages to map the donor chromosome with transduction. The phage lysate from the bacterial cells is collected and used to infect a second strain of bacteria that are a_ b_ c_.

Based on the above, which one of the following conclusions is correct?