All animals with eyes or eyespots that have been studied so far share a gene in common. When mutated, the gene Pax-6 causes lack of eyes in fruit flies, tiny eyes in mice, and missing irises (and other eye parts) in humans. The sequence of Pax-6 in humans and mice is identical. There are so few sequence differences with fruit fly Pax-6 that the human/mouse version can cause eye formation in eyeless fruit flies, even though vertebrates and invertebrates last shared a common ancestor more than 500 million years ago.

The appearance of Pax-6 in all animals with eyes can be explained in multiple ways. Based on the information above, which explanation is most likely?

#Question id: 10561

#Unit 6. System Physiology – Plant

Integral membrane proteins that form water-selective channels across the membrane, Because water diffuses faster through such channels than through a lipid bilayer

#Question id: 10562

#Unit 6. System Physiology – Plant

The direction and rate of water flow across a membrane are determined by

#Question id: 10563

#Unit 6. System Physiology – Plant

The rate of diffusion depend upon

#Question id: 10564

#Unit 6. System Physiology – Plant

The term Ys , called the solute potential or the osmotic potential, represents the effect of dissolved solutes on water potential,

a) The mixing of solutes and water reduces the disorder of the system and thereby lowers free energy

b) Solutes reduce the free energy of water by diluting the water

c) The mixing of solutes and water increases the disorder of the system and thereby lowers free energy

d) Solutes increases the free energy of water by diluting the water

 Which one of the following statements are INCORRECT?

#Question id: 10565

#Unit 6. System Physiology – Plant

The term Yp is the hydrostatic pressure of the solution

#Question id: 10566

#Unit 6. System Physiology – Plant

What happens if this cell is placed in the beaker containing 0.1 M sucrose, Because the water potential of the sucrose solution (Yw = –0.244) is greater than the water potential of the cell (Yw = –0.732 MPa)

a) Water will move from the cell to the sucrose solution

b) From high to low water potential

c) From low to high water potential

d) Water will move from the sucrose solution to the cell

Which of the following statement is CORRECT?