Sox9 is an autosomal gene involved in several developmental processes, most notably bone formation. In the gonadal rudiments, Sox9 induces testis formation. Expression of the Sox9 gene is specifically upregulated by the combined expression of Sry and Sf1 proteins in Sertoli cell precursors. Thus, Sry may act merely as a “switch” operating during a very short time to activate Sox9, and the Sox9 protein may initiate the conserved evolutionary pathway to testis formation. Following statements are regarding to the functions of Sox9.

A. It appears to be able to activate its own promoter, thereby allowing it to be transcribed for long periods of time.

B. It activates the ability of β-catenin to induce ovary formation, either directly or indirectly.

C. It binds to cis-regulatory regions of numerous genes necessary for testis production.

D. Sox9 binds to the promoter site on the gene for anti-Müllerian hormone, providing a critical link in the pathway toward a male phenotype.

E. Sox9 inhibits the expression of the gene encoding Fgf9, a paracrine factor.

Which of the following statements are correct?

#Question id: 9591

#Unit 6. System Physiology – Plant

In light reaction, the funneling of excitation from the antenna system toward the reaction centre has been shown,

a.) The excited-state energy of pigments increases with distance from the reaction centre; that is, pigments closer to the reaction centre are lower in energy than those farther from the reaction centre

b.) The energy gradient ensures that excitation transfer toward the reaction centre is energetically favorable and that excitation transfer back out to the peripheral portions of the antenna is energetically unfavourable

c.) Some energy is lost as heat to the environment by this process, but under optimal conditions almost all the excitation energy absorbed in the antenna complexes can be delivered to the reaction centre

d.) The excited-state energy of  pigments decreases with distance from the reaction centre

Which of the following above combination is true?

#Question id: 9592

#Unit 6. System Physiology – Plant

The function of light is to excite a specialized chlorophyll in the reaction centre either by Direct absorption or more frequently, via energy transfer from an antenna pigment, This excitation process can be envisioned as

a.) An electron from the lowest-energy filled orbital of the chlorophyll to the highest-energy unfilled orbital

b.) An electron in the upper orbital is only tightly bound to the chlorophyll and is difficult to fetch the electron nearby molecules

c.)  The electron in the upper orbital is only loosely bound to the chlorophyll and is easily lost if a molecule that can accept the electron is nearby

d.) The promotion of an electron from the highest-energy filled orbital of the chlorophyll to the lowest-energy unfilled orbital

Which combination is CORRECT?

#Question id: 9593

#Unit 6. System Physiology – Plant

The lower-energy orbital of the positively charged oxidized reaction centre chlorophyll has a vacancy and can accept an electron If the acceptor molecule donates its electron back to the reaction centre chlorophyll, What will happened?

#Question id: 9594

#Unit 6. System Physiology – Plant

The first reaction that converts electron energy into chemical energy—What will happened in  the primary photochemical event—

#Question id: 9595

#Unit 6. System Physiology – Plant

The process is that the absorbed photon causes an electron rearrangement in the reaction centre chlorophyll, followed by an electron transfer process in which part of the energy in the photon is captured in the form of

#Question id: 9596

#Unit 6. System Physiology – Plant

The reaction centre chlorophyll is transiently in an oxidized state after losing an electron and before being re-reduced by its electron donor, what characteristics has been shown by chlorophylls in an oxidized state?