The hormone that stimulates uterine contractions during childbirth is: MCQ with Answer and Explanation

Explanation:
Producers (green plants, algae, cyanobacteria) form the first trophic level, converting solar energy into biomass. Consumers depend on them.

Explanation:
Geotropism (gravitropism) is directional growth in response to gravity; roots show positive geotropism (downward), shoots negative (upward). Phototropism is light-directed, thigmotropism touch, hydrotropism water.

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.