Which event in Earth's history most directly allowed life to exist on land? Earth's temperatures increased, causing widespread evaporation.
Earth collided with a large object, forming the moon.
Single-celled organisms released oxygen into the air when they photosynthesized.
Single-celled organisms absorbed harmful gases from the air when they first formed.

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.

Overtime the pond slowly becomes more acidic due to the release of chemicals from a nearby factory. which of the organisms would most likely survive the change to their environment?

Which number represents a basic ph, 4 or 9? numerical answers expected! answer for blank 1: i'll give