Following statements regarding to the molecular processes of capacitation.

A. The sperm cell membrane is altered by the removal of albumin by cholesterol in the female reproductive tract.

B. Particular proteins or carbohydrates on the sperm surface are lost during decapacitation.

C. The membrane potential of the sperm cell becomes more positive as potassium ions leave the sperm. This change in membrane potential may allow calcium channels to be opened and permit calcium to enter the sperm.

D. Calcium and bicarbonate ions are critical in activating cAMP production and in facilitating the membrane fusion events of the acrosome reaction.

E. As a result of cAMP formation, protein phosphorylation occurs. Once they are phosphorylated, some proteins migrate to the surface of the sperm head. One of these proteins is izumo, which is critical in sperm-egg fusion.

which one of the following combinations is correct?

#Question id: 10224

#Unit 6. System Physiology – Plant

Exposure to high levels of excess light that damage the photosynthetic system and decrease both quantum efficiency and maximum photosynthetic rate results

#Question id: 10225

#Unit 6. System Physiology – Plant

Air circulation around the leaf removes heat from the leaf surfaces if the temperature of the leaf is higher than that of the air; this phenomenon is called

#Question id: 10226

#Unit 6. System Physiology – Plant

Under moderate excess light Quantum efficiency decreases , but the maximum photosynthetic rate remains unchanged and caused by the diversion of absorbed light energy toward heat dissipation—hence the decrease in quantum efficiency this term is known as

#Question id: 10227

#Unit 6. System Physiology – Plant

The evaporation of water requires energy, when water evaporates from a leaf (transpiration), it removes large amounts of heat from the leaf and thus cools it. The human body is cooled by the same principle, commonly known as

#Question id: 10228

#Unit 6. System Physiology – Plant

Photorespiration and the quantum yield differ between C3 and C4 photosynthesis, with changes particularly noticeable as temperatures vary quantum yield for photosynthesis as a function of leaf temperature in C3 plants and C4 plants. Following are some statements  based on this study.

 a.) In the C4 plants the quantum yield remains constant with temperature, reflecting low rates of photorespiration

 b.) At lower temperatures the quantum yield of C3 plants is higher than that of C4 plants

c.) C3 photosynthesis is more efficient at lower temperatures

 d.) At higher temperatures the quantum yield of C3 plants is higher  than that of C4 plants

 Which one of the following combination of above statements is correct?

#Question id: 10229

#Unit 6. System Physiology – Plant

Comparing such a plot for C3 and C4 plants reveals differences between the two pathways of carbon metabolism, which of the following given statements will be incorrect?