Both cellular respiration and photosynthesis rely on electron transport chains embedded in membranes to produce ATP molecules. Which of the following correctly describes the difference between the two types of electron transport chains?

a. in cellular respiration the electron source is water and the final electron destination is oxygen.

b. in cellular respiration the electron source is the hydrogens in energy rich food and the final electron destination is oxygen.

c. in photosynthesis the electron source is water and the final destination is oxygen.

d. both b and c.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]

answer: the correct option is d. enzyme

lactase and carbonic anhydrase are the examples of enzymes.

lactase is an enzyme, which is present in the small intestine of mammals. it in the digestion of the disaccharide, lactose ( milk sugar) by converting it into two monosachharide, which are glucose and galactose.

carbonic anhydrase is present in the red blood cells. this enzyme plays significant role in the transport of co₂. it in the conversion of co₂ and h₂o into carbonic acid, which is then dissociated into bicarbonate ions and hydrogen ions.