An experiment was done to see the effect of auxin: cytokinin ratios on morphogenesis can also be seen in crown gall tumors by mutation of the T-DNA of the Agrobacterium Ti plasmid,

I) Mutating the ipt gene (the tmr locus) of the Ti plasmid blocks zeatin biosynthesis in the infected cells

II) mutating either of the genes for auxin biosynthesis (tms locus)

Given some results about these above mutations ,

a) equal auxin to cytokinin ratio form undifferentiated callus tissue

b) high auxin:cytokinin ratio in the tumor cells causes the proliferation of roots instead of undifferentiated callus tissue

c) lowers the auxin:cytokinin ratio and stimulates the proliferation of shoots

What would be the result of these two mutation ?

#Question id: 11079

#Unit 7. System Physiology – Animal

The diffusing capacity of a gas is the volume of gas that will diffuse through a membrane each minute for a pressure difference of 1 mm Hg. Which of the following gases is often used to estimate the oxygen diffusing capacity of the lungs?

#Question id: 11080

#Unit 7. System Physiology – Animal

The O2-CO2 diagram here shows a ventilation-perfusion ratio line for the normal lung. Which of the following best describes the effect of decreasing ventilation-perfusion ratio on the alveolar Po2 and Pco2?

#Question id: 11081

#Unit 7. System Physiology – Animal

In which of the following conditions is alveolar Po2 increased and alveolar Pco2 decreased?

#Question id: 11082

#Unit 7. System Physiology – Animal

A 67-year-old man has a solid tumor that pushes against an airway partially obstructing air flow to the distal alveoli. Which point on the ventilation-perfusion line of the O2-CO2 diagram corresponds to the alveolar gas of these distal alveoli?

#Question id: 11083

#Unit 7. System Physiology – Animal

A 55-year-old male has a pulmonary embolism that partially blocks the blood flow to his right lung. Which point on the ventilation-perfusion line of the O2-CO2 diagram corresponds to the alveolar gas of his right lung?

#Question id: 11084

#Unit 7. System Physiology – Animal

The next diagram shows two lung units (S and T) with their blood supplies. Lung unit S has an ideal relationship between blood flow and ventilation. Lung unit T has a comprised blood flow. What is the relationship between alveolar dead space (DALV), physiologic dead space (DPHY) and anatomic dead space (DANAT) for these lung units?