Oxygen-rich blood enters the heart through the . vena cava
pulmonary artery
aorta
pulmonary vein

As a result of wildfires, in grasslands. a) tree growth increases b) grass growth increases c) soil quality decreases d) invertebrate variety decreases

Asolution of an enzyme and a substrate was placed in a water bath and the temperature of the reaction was raised gradually. the graph shown was plotted at the end of the experiment. what can be concluded from the graph? a) temperature has no effect on the activity of the enzyme. b) the effect of temperature on the enzyme is unpredictable. c) the enzyme shows increased activity up to a certain temperature. d) the activity of the enzyme is inversely proportional to the temperature.

The tubes transporting minerals and water upward are called ?