Consider the following statements about the carbon cycle: 1. Photosynthesis removes CO₂ from the atmosphere. 2. Respiration and combustion return CO₂ to the atmosphere. 3. Decomposition releases CO₂. Which of the above is/are correct? MCQ with Answer and Explanation

Explanation:
Charles Darwin and Alfred Wallace independently proposed natural selection as the mechanism for evolution. Darwin published 'On the Origin of Species' in 1859.

Explanation:
The Bohr effect describes how an increase in pCO2 or a decrease in pH (increase in H+) reduces hemoglobin's affinity for oxygen, shifting the oxygen dissociation curve to the right and promoting oxygen unloading. Conversely, in the lungs, where pCO2 is low and pH is relatively higher (more alkaline), the Bohr effect works in reverse: hemoglobin's affinity for oxygen increases, facilitating the loading (binding) of oxygen to hemoglobin. The Haldane effect describes the reciprocal relationship for CO2 transport.

Explanation:
Sedimentary rocks, such as limestone, shale, and sandstone, form in layers from accumulated sediments and preserve remains of organisms as fossils. Igneous rocks from volcanic activity and metamorphic rocks formed under high temperature/pressure rarely contain fossils. The fossil record provides evidence for evolution, showing gradual changes in species over geological time. Fossils include bones, shells, imprints, and amber inclusions.