If all other factors affecting photosynthetic rates were equal and atmospheric co2 concentration were the main factor affecting photo synthetic rates, how woulf plant growth in an area that is about 30 degrees c in the daytime have changedover the course of the past 400,000 years?

The rate of photosynthesis is greatly affected by the temperature of the surrounding.

Temperature has a direct effect on the photosynthesis rates. If the temperature is too high or too low then the photosynthesis rates decreases but at optimum temperature, the photosynthesis rate increases.

If the temperature is about 30 degree Celsius the rate of photosynthesis at its peak because of the activity of RUBISCO enzyme increased that leads to higher production of glucose by the plant body so we can conclude that the rate of photosynthesis is greatly affected by the temperature of the surrounding.

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plant growth rate will remain the same

Explanation:

Photosynthesis is the process by which green plants generate carbohydrates (sugars) and oxygen from carbon dioxide, water, and light energy.

The balanced equation is as follows: 6CO2 + 6H20 + (solar energy) → C6H12O6 + 6O2

Note that "all other factors affecting photosynthetic rates were equal, ONLY atmospheric CO2 concentration were the main factor affecting photo synthetic rates"; then time (400, 000years) and 30 degrees C in the daytime temperature of 30°c will mean nothing.

Plants' chlorophyll will only trap the solar energy required to combine 6 moles of CO2 to 6 moles of H2O. Hence,

i think its c. amphipod

"a.) well–developed vascular system."