The effect that yellowed or light-green leaves would have on a cucumber or tobacco plant

The effect would be that the green leaves, which contain chloroplasts, containing a chemical called chlorophyll would enable the plants to take in more energy in the form of sunlight, enabling the plants to photosynthesise and grow.

not too sure but maybe in the hot springs.

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.